Mysql memory usage growing until OOM and system kills / restarts - mysql
I have MySQL 5.7.27 under Ubuntu 16.04.4, 64 bit, 4GB RAM and SSDs (it's a virtual machine). I am observing resident memory growth in mysqld until no more resources are available and the OS kills / restarts mysqld.
Some background - The system is used to collect information from remote locations, with 1 entity being collected from each location. Each entity might have many hundreds of data points. For each remote location, there are two databases, which supports two situations: each location is per customer (but one customer might have many - thousands - of such locations) and in some situations, it might be many thousands of entities being collected from each remote location. The two DBs correspond to raw data collected and "processed" summaries. In addition, there is one additional DB per customer recording admin and other data about each remote location. So, total DB count is C * ( 1 + 2L ) - C for customer, L for location. The first DB of 2L has 32 tables and a minimum size of 2MB (but I have at least one example which it 5.9GB - not in this current sample set) - it is "cleared" at the start of each collection event; the second has 12 tables and typical size in the current sample set is 1MB (although this accumulates for each collection event).
A remote collection is performed periodically, say once a week or once a month, per remote location. After each collection, a process is run to summarise data from the ALL of the 2L databases into the one unifying one.
In the system with the issue, there are C ( 1 + 2L ) equaling just over 5000. When the summarisation process is run, mysqld resident memory (viewed using top) grows from around 800MB to just under 3GB. The summarisation process completes and might then run again a short time afterwards. That process completes cleanly and correctly releases query results and closes DB connections. The application is PHP 7.2.24 CLI running locally (so, using sockets, not TCP).
I have tried "tuning":
open_files_limit = 11000
table_open_cache = 5200
innodb_lru_scan_depth = 128
innodb_flush_log_at_trx_commit = 2
innodb_buffer_pool_size = 1073741824
(see open_files_limit, table_open_cache, innodb_lru_scan_depth, innodb_flush_log_at_trx_commit, innodb_buffer_pool_size)
These either made no apparent change or worsened the rate of growth of memory usage. I also ran show engine performance_schema status; at three instances: when resident memory was at 2459MB, 2478MB and 2910MB. Between those three samples, I saw differences only in the following metrics:
2459MB 2478MB 2910MB
(digest_hash).count 4676 -> 4837 -> 4958
(filename_hash).count 121118 -> 121139 -> 121214
(table_share_hash).count 27229 -> 27247 -> 27276
mutex_instances.count 29696 -> 30720 -> 31744
mutex_instances.memory 3801088 -> 3932160 -> 4063232
performance_scheme.memory 426293432 -> 426424504 -> 4266886648
rwlock_instances.count 400384 -> 400384 -> 401408
rwlock_instances.memory 51249152 -> 51249152 -> 51380224
My expectation is that at the end of each summarisation run, either "temporary" buffer space in mysqld would be freed up, or would simply be reused at the next run of that process, given that it effectively is making the same sequence of queries (and very similar updates) across the same set of databases / tables. The fact that the memory footprint grows suggest to me that either there is a memory leak in mysqld, or that an intentional "buffer" related to some failure condition (connections, locks, mutexes?) is at least part of the cause of the memory growth. I suggest the latter, because I would look at what would persist in mysqld between subsequent runs of that summarisation process.
I have also tried running mysqltuner.pl (see http://mysqltuner.com), but this also causes the memory growth problem, which is undoubtedly related to the number of databases. However, if I might refer to https://dev.mysql.com/doc/refman/5.7/en/database-count-limit.html, whatever limit MySQL might or might not have to the number of databases and tables, the numbers here are not significant to mysqld itself, even if they might be to the underlying OS. I confess I was impressed that the server was apparently handling over 1000 SELECTS per second on a not very highly spec'd system.
So, What "monitoring" parameters should I be looking at to assist with tuning mysql, the OS or platform and what (mysql / OS) tuning parameters would be most helpful in this situation? I could just take the Jaws approach ("We're going to need a bigger boat"), but if the issue I'm experiencing is a memory leak, then just adding more RAM is only just postponing the inevitable.
------------ EDIT following answer by Rick James (2020/01/13) -
RAM - 4GB
SHOW VARIABLES; (less SSL related info) output:
auto_generate_certs ON
auto_increment_increment 1
auto_increment_offset 1
autocommit ON
automatic_sp_privileges ON
avoid_temporal_upgrade OFF
back_log 80
basedir /usr/
big_tables OFF
bind_address *
binlog_cache_size 32768
binlog_checksum CRC32
binlog_direct_non_transactional_updates OFF
binlog_error_action ABORT_SERVER
binlog_format ROW
binlog_group_commit_sync_delay 0
binlog_group_commit_sync_no_delay_count 0
binlog_gtid_simple_recovery ON
binlog_max_flush_queue_time 0
binlog_order_commits ON
binlog_row_image FULL
binlog_rows_query_log_events OFF
binlog_stmt_cache_size 32768
binlog_transaction_dependency_history_size 25000
binlog_transaction_dependency_tracking COMMIT_ORDER
block_encryption_mode aes-128-ecb
bulk_insert_buffer_size 8388608
character_set_client utf8mb4
character_set_connection utf8mb4
character_set_database utf8
character_set_filesystem binary
character_set_results utf8mb4
character_set_server utf8
character_set_system utf8
character_sets_dir /usr/share/mysql/charsets/
check_proxy_users OFF
collation_connection utf8mb4_general_ci
collation_database utf8_unicode_ci
collation_server utf8_unicode_ci
completion_type NO_CHAIN
concurrent_insert AUTO
connect_timeout 10
core_file OFF
datadir /var/lib/mysql/
date_format %Y-%m-%d
datetime_format %Y-%m-%d %H:%i:%s
default_authentication_plugin mysql_native_password
default_password_lifetime 0
default_storage_engine InnoDB
default_tmp_storage_engine InnoDB
default_week_format 0
delay_key_write ON
delayed_insert_limit 100
delayed_insert_timeout 300
delayed_queue_size 1000
disabled_storage_engines
disconnect_on_expired_password ON
div_precision_increment 4
end_markers_in_json OFF
enforce_gtid_consistency OFF
eq_range_index_dive_limit 200
error_count 0
event_scheduler OFF
expire_logs_days 10
explicit_defaults_for_timestamp OFF
external_user
flush OFF
flush_time 0
foreign_key_checks ON
ft_boolean_syntax + -><()~*:""&|
ft_max_word_len 84
ft_min_word_len 4
ft_query_expansion_limit 20
ft_stopword_file (built-in)
general_log OFF
general_log_file /var/lib/mysql/demo.log
group_concat_max_len 1024
gtid_executed_compression_period 1000
gtid_mode OFF
gtid_next AUTOMATIC
gtid_owned
gtid_purged
have_compress YES
have_crypt YES
have_dynamic_loading YES
have_geometry YES
have_openssl YES
have_profiling YES
have_query_cache YES
have_rtree_keys YES
have_ssl YES
have_statement_timeout YES
have_symlink YES
host_cache_size 279
hostname <hidden>
identity 0
ignore_builtin_innodb OFF
ignore_db_dirs
init_connect
init_file
init_slave
innodb_adaptive_flushing ON
innodb_adaptive_flushing_lwm 10
innodb_adaptive_hash_index ON
innodb_adaptive_hash_index_parts 8
innodb_adaptive_max_sleep_delay 150000
innodb_api_bk_commit_interval 5
innodb_api_disable_rowlock OFF
innodb_api_enable_binlog OFF
innodb_api_enable_mdl OFF
innodb_api_trx_level 0
innodb_autoextend_increment 64
innodb_autoinc_lock_mode 1
innodb_buffer_pool_chunk_size 134217728
innodb_buffer_pool_dump_at_shutdown ON
innodb_buffer_pool_dump_now OFF
innodb_buffer_pool_dump_pct 25
innodb_buffer_pool_filename ib_buffer_pool
innodb_buffer_pool_instances 1
innodb_buffer_pool_load_abort OFF
innodb_buffer_pool_load_at_startup ON
innodb_buffer_pool_load_now OFF
innodb_buffer_pool_size 134217728
innodb_change_buffer_max_size 25
innodb_change_buffering all
innodb_checksum_algorithm crc32
innodb_checksums ON
innodb_cmp_per_index_enabled OFF
innodb_commit_concurrency 0
innodb_compression_failure_threshold_pct 5
innodb_compression_level 6
innodb_compression_pad_pct_max 50
innodb_concurrency_tickets 5000
innodb_data_file_path ibdata1:12M:autoextend
innodb_data_home_dir
innodb_deadlock_detect ON
innodb_default_row_format dynamic
innodb_disable_sort_file_cache OFF
innodb_doublewrite ON
innodb_fast_shutdown 1
innodb_file_format Barracuda
innodb_file_format_check ON
innodb_file_format_max Barracuda
innodb_file_per_table ON
innodb_fill_factor 100
innodb_flush_log_at_timeout 1
innodb_flush_log_at_trx_commit 2
innodb_flush_method
innodb_flush_neighbors 1
innodb_flush_sync ON
innodb_flushing_avg_loops 30
innodb_force_load_corrupted OFF
innodb_force_recovery 0
innodb_ft_aux_table
innodb_ft_cache_size 8000000
innodb_ft_enable_diag_print OFF
innodb_ft_enable_stopword ON
innodb_ft_max_token_size 84
innodb_ft_min_token_size 3
innodb_ft_num_word_optimize 2000
innodb_ft_result_cache_limit 2000000000
innodb_ft_server_stopword_table
innodb_ft_sort_pll_degree 2
innodb_ft_total_cache_size 640000000
innodb_ft_user_stopword_table
innodb_io_capacity 200
innodb_io_capacity_max 2000
innodb_large_prefix ON
innodb_lock_wait_timeout 50
innodb_locks_unsafe_for_binlog OFF
innodb_log_buffer_size 16777216
innodb_log_checksums ON
innodb_log_compressed_pages ON
innodb_log_file_size 50331648
innodb_log_files_in_group 2
innodb_log_group_home_dir ./
innodb_log_write_ahead_size 8192
innodb_lru_scan_depth 128
innodb_max_dirty_pages_pct 75
innodb_max_dirty_pages_pct_lwm 0
innodb_max_purge_lag 0
innodb_max_purge_lag_delay 0
innodb_max_undo_log_size 1073741824
innodb_monitor_disable
innodb_monitor_enable
innodb_monitor_reset
innodb_monitor_reset_all
innodb_numa_interleave OFF
innodb_old_blocks_pct 37
innodb_old_blocks_time 1000
innodb_online_alter_log_max_size 134217728
innodb_open_files 5200
innodb_optimize_fulltext_only OFF
innodb_page_cleaners 1
innodb_page_size 16384
innodb_print_all_deadlocks OFF
innodb_purge_batch_size 300
innodb_purge_rseg_truncate_frequency 128
innodb_purge_threads 4
innodb_random_read_ahead OFF
innodb_read_ahead_threshold 56
innodb_read_io_threads 4
innodb_read_only OFF
innodb_replication_delay 0
innodb_rollback_on_timeout OFF
innodb_rollback_segments 128
innodb_sort_buffer_size 1048576
innodb_spin_wait_delay 6
innodb_stats_auto_recalc ON
innodb_stats_include_delete_marked OFF
innodb_stats_method nulls_equal
innodb_stats_on_metadata OFF
innodb_stats_persistent ON
innodb_stats_persistent_sample_pages 20
innodb_stats_sample_pages 8
innodb_stats_transient_sample_pages 8
innodb_status_output OFF
innodb_status_output_locks OFF
innodb_strict_mode ON
innodb_support_xa ON
innodb_sync_array_size 1
innodb_sync_spin_loops 30
innodb_table_locks ON
innodb_temp_data_file_path ibtmp1:12M:autoextend
innodb_thread_concurrency 0
innodb_thread_sleep_delay 10000
innodb_tmpdir
innodb_undo_directory ./
innodb_undo_log_truncate OFF
innodb_undo_logs 128
innodb_undo_tablespaces 0
innodb_use_native_aio ON
innodb_version 5.7.28
innodb_write_io_threads 4
insert_id 0
interactive_timeout 28800
internal_tmp_disk_storage_engine InnoDB
join_buffer_size 262144
keep_files_on_create OFF
key_buffer_size 16777216
key_cache_age_threshold 300
key_cache_block_size 1024
key_cache_division_limit 100
keyring_operations ON
large_files_support ON
large_page_size 0
large_pages OFF
last_insert_id 0
lc_messages en_US
lc_messages_dir /usr/share/mysql/
lc_time_names en_US
license GPL
local_infile ON
lock_wait_timeout 31536000
locked_in_memory OFF
log_bin OFF
log_bin_basename
log_bin_index
log_bin_trust_function_creators OFF
log_bin_use_v1_row_events OFF
log_builtin_as_identified_by_password OFF
log_error /var/log/mysql/error.log
log_error_verbosity 3
log_output FILE
log_queries_not_using_indexes OFF
log_slave_updates OFF
log_slow_admin_statements OFF
log_slow_slave_statements OFF
log_statements_unsafe_for_binlog ON
log_syslog OFF
log_syslog_facility daemon
log_syslog_include_pid ON
log_syslog_tag
log_throttle_queries_not_using_indexes 0
log_timestamps UTC
log_warnings 2
long_query_time 10
low_priority_updates OFF
lower_case_file_system OFF
lower_case_table_names 0
master_info_repository FILE
master_verify_checksum OFF
max_allowed_packet 16777216
max_binlog_cache_size 1.84467440737095E+019
max_binlog_size 104857600
max_binlog_stmt_cache_size 1.84467440737095E+019
max_connect_errors 100
max_connections 151
max_delayed_threads 20
max_digest_length 1024
max_error_count 64
max_execution_time 0
max_heap_table_size 16777216
max_insert_delayed_threads 20
max_join_size 1.84467440737096E+019
max_length_for_sort_data 1024
max_points_in_geometry 65536
max_prepared_stmt_count 16382
max_relay_log_size 0
max_seeks_for_key 1.84467440737096E+019
max_sort_length 1024
max_sp_recursion_depth 0
max_tmp_tables 32
max_user_connections 0
max_write_lock_count 1.84467440737096E+019
metadata_locks_cache_size 1024
metadata_locks_hash_instances 8
min_examined_row_limit 0
multi_range_count 256
myisam_data_pointer_size 6
myisam_max_sort_file_size 9.22337203685373E+018
myisam_mmap_size 1.84467440737096E+019
myisam_recover_options BACKUP
myisam_repair_threads 1
myisam_sort_buffer_size 8388608
myisam_stats_method nulls_unequal
myisam_use_mmap OFF
mysql_native_password_proxy_users OFF
net_buffer_length 16384
net_read_timeout 30
net_retry_count 10
net_write_timeout 60
new OFF
ngram_token_size 2
offline_mode OFF
old OFF
old_alter_table OFF
old_passwords 0
open_files_limit 11000
optimizer_prune_level 1
optimizer_search_depth 62
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,duplicateweedout=on,subquery_materialization_cost_based=on,use_index_extensions=on,condition_fanout_filter=on,derived_merge=on
optimizer_trace enabled=off,one_line=off
optimizer_trace_features greedy_search=on,range_optimizer=on,dynamic_range=on,repeated_subselect=on
optimizer_trace_limit 1
optimizer_trace_max_mem_size 16384
optimizer_trace_offset -1
parser_max_mem_size 1.84467440737096E+019
performance_schema ON
performance_schema_accounts_size -1
performance_schema_digests_size 10000
performance_schema_events_stages_history_long_size 10000
performance_schema_events_stages_history_size 10
performance_schema_events_statements_history_long_size 10000
performance_schema_events_statements_history_size 10
performance_schema_events_transactions_history_long_size 10000
performance_schema_events_transactions_history_size 10
performance_schema_events_waits_history_long_size 10000
performance_schema_events_waits_history_size 10
performance_schema_hosts_size -1
performance_schema_max_cond_classes 80
performance_schema_max_cond_instances -1
performance_schema_max_digest_length 1024
performance_schema_max_file_classes 80
performance_schema_max_file_handles 32768
performance_schema_max_file_instances -1
performance_schema_max_index_stat -1
performance_schema_max_memory_classes 320
performance_schema_max_metadata_locks -1
performance_schema_max_mutex_classes 210
performance_schema_max_mutex_instances -1
performance_schema_max_prepared_statements_instances -1
performance_schema_max_program_instances -1
performance_schema_max_rwlock_classes 50
performance_schema_max_rwlock_instances -1
performance_schema_max_socket_classes 10
performance_schema_max_socket_instances -1
performance_schema_max_sql_text_length 1024
performance_schema_max_stage_classes 150
performance_schema_max_statement_classes 193
performance_schema_max_statement_stack 10
performance_schema_max_table_handles -1
performance_schema_max_table_instances -1
performance_schema_max_table_lock_stat -1
performance_schema_max_thread_classes 50
performance_schema_max_thread_instances -1
performance_schema_session_connect_attrs_size 512
performance_schema_setup_actors_size -1
performance_schema_setup_objects_size -1
performance_schema_users_size -1
pid_file /var/run/mysqld/mysqld.pid
plugin_dir /usr/lib/mysql/plugin/
port 3306
preload_buffer_size 32768
profiling OFF
profiling_history_size 15
protocol_version 10
proxy_user
pseudo_slave_mode OFF
pseudo_thread_id 8224
query_alloc_block_size 8192
query_cache_limit 1048576
query_cache_min_res_unit 4096
query_cache_size 16777216
query_cache_type OFF
query_cache_wlock_invalidate OFF
query_prealloc_size 8192
rand_seed1 0
rand_seed2 0
range_alloc_block_size 4096
range_optimizer_max_mem_size 8388608
rbr_exec_mode STRICT
read_buffer_size 131072
read_only OFF
read_rnd_buffer_size 262144
relay_log
relay_log_basename /var/lib/mysql/demo-relay-bin
relay_log_index /var/lib/mysql/demo-relay-bin.index
relay_log_info_file relay-log.info
relay_log_info_repository FILE
relay_log_purge ON
relay_log_recovery OFF
relay_log_space_limit 0
report_host
report_password
report_port 3306
report_user
require_secure_transport ON
rpl_stop_slave_timeout 31536000
secure_auth ON
secure_file_priv /var/lib/mysql-files/
server_id 0
server_id_bits 32
server_uuid <hidden>
session_track_gtids OFF
session_track_schema ON
session_track_state_change OFF
session_track_system_variables time_zone,autocommit,character_set_client,character_set_results,character_set_connection
session_track_transaction_info OFF
sha256_password_auto_generate_rsa_keys ON
sha256_password_private_key_path private_key.pem
sha256_password_proxy_users OFF
sha256_password_public_key_path public_key.pem
show_compatibility_56 OFF
show_create_table_verbosity OFF
show_old_temporals OFF
skip_external_locking ON
skip_name_resolve OFF
skip_networking OFF
skip_show_database OFF
slave_allow_batching OFF
slave_checkpoint_group 512
slave_checkpoint_period 300
slave_compressed_protocol OFF
slave_exec_mode STRICT
slave_load_tmpdir /tmp
slave_max_allowed_packet 1073741824
slave_net_timeout 60
slave_parallel_type DATABASE
slave_parallel_workers 0
slave_pending_jobs_size_max 16777216
slave_preserve_commit_order OFF
slave_rows_search_algorithms TABLE_SCAN,INDEX_SCAN
slave_skip_errors OFF
slave_sql_verify_checksum ON
slave_transaction_retries 10
slave_type_conversions
slow_launch_time 2
slow_query_log OFF
slow_query_log_file /var/lib/mysql/demo-slow.log
socket /var/run/mysqld/mysqld.sock
sort_buffer_size 262144
sql_auto_is_null OFF
sql_big_selects ON
sql_buffer_result OFF
sql_log_bin ON
sql_log_off OFF
sql_mode ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
sql_notes ON
sql_quote_show_create ON
sql_safe_updates OFF
sql_select_limit 1.84467440737096E+019
sql_slave_skip_counter 0
sql_warnings OFF
stored_program_cache 256
super_read_only OFF
sync_binlog 1
sync_frm ON
sync_master_info 10000
sync_relay_log 10000
sync_relay_log_info 10000
system_time_zone GMT
table_definition_cache 2000
table_open_cache 5200
table_open_cache_instances 16
thread_cache_size 8
thread_handling one-thread-per-connection
thread_stack 262144
time_format %H:%i:%s
time_zone SYSTEM
timestamp 1579095336.07864
tls_version TLSv1,TLSv1.1,TLSv1.2
tmp_table_size 16777216
tmpdir /tmp
transaction_alloc_block_size 8192
transaction_allow_batching OFF
transaction_isolation REPEATABLE-READ
transaction_prealloc_size 4096
transaction_read_only OFF
transaction_write_set_extraction OFF
tx_isolation REPEATABLE-READ
tx_read_only OFF
unique_checks ON
updatable_views_with_limit YES
version 5.7.28-0ubuntu0.16.04.2
version_comment (Ubuntu)
version_compile_machine x86_64
version_compile_os Linux
wait_timeout 28800
warning_count 0
SHOW GLOBAL STATUS; (less SSL related info and any com_*=0 values) output:
Aborted_clients 0
Aborted_connects 4
Binlog_cache_disk_use 0
Binlog_cache_use 0
Binlog_stmt_cache_disk_use 0
Binlog_stmt_cache_use 0
Bytes_received 120596117
Bytes_sent 423055987
Com_admin_commands 1422
Com_change_db 1969
Com_delete 26
Com_delete_multi 5
Com_flush 5
Com_insert 543
Com_lock_tables 106103
Com_select 290121
Com_set_option 3952
Com_show_charsets 4
Com_show_fields 1756
Com_show_keys 3
Com_show_plugins 1
Com_show_status 2317
Com_show_tables 4
Com_show_variables 10
Com_unlock_tables 106103
Com_update 119462
Connection_errors_accept 0
Connection_errors_internal 0
Connection_errors_max_connections 0
Connection_errors_peer_address 0
Connection_errors_select 0
Connection_errors_tcpwrap 0
Connections 53918
Created_tmp_disk_tables 7205
Created_tmp_files 6
Created_tmp_tables 26682
Delayed_errors 0
Delayed_insert_threads 0
Delayed_writes 0
Flush_commands 1
Handler_commit 516258
Handler_delete 605
Handler_discover 0
Handler_external_lock 1131715
Handler_mrr_init 0
Handler_prepare 0
Handler_read_first 251891
Handler_read_key 1450835
Handler_read_last 0
Handler_read_next 46912240
Handler_read_prev 0
Handler_read_rnd 333804
Handler_read_rnd_next 77706400
Handler_rollback 0
Handler_savepoint 0
Handler_savepoint_rollback 0
Handler_update 20612
Handler_write 139820
Innodb_buffer_pool_dump_status Dumping of buffer pool not started
Innodb_buffer_pool_load_status Buffer pool(s) load completed at 200110 15:44:11
Innodb_buffer_pool_resize_status
Innodb_buffer_pool_pages_data 7744
Innodb_buffer_pool_bytes_data 126877696
Innodb_buffer_pool_pages_dirty 0
Innodb_buffer_pool_bytes_dirty 0
Innodb_buffer_pool_pages_flushed 10525
Innodb_buffer_pool_pages_free 128
Innodb_buffer_pool_pages_misc 319
Innodb_buffer_pool_pages_total 8191
Innodb_buffer_pool_read_ahead_rnd 0
Innodb_buffer_pool_read_ahead 2174
Innodb_buffer_pool_read_ahead_evicted 552
Innodb_buffer_pool_read_requests 92861248
Innodb_buffer_pool_reads 230500
Innodb_buffer_pool_wait_free 0
Innodb_buffer_pool_write_requests 490867
Innodb_data_fsyncs 6682
Innodb_data_pending_fsyncs 0
Innodb_data_pending_reads 0
Innodb_data_pending_writes 0
Innodb_data_read 3812250112
Innodb_data_reads 257019
Innodb_data_writes 36166
Innodb_data_written 301705728
Innodb_dblwr_pages_written 5776
Innodb_dblwr_writes 1121
Innodb_log_waits 0
Innodb_log_write_requests 24009
Innodb_log_writes 23298
Innodb_os_log_fsyncs 3651
Innodb_os_log_pending_fsyncs 0
Innodb_os_log_pending_writes 0
Innodb_os_log_written 34017280
Innodb_page_size 16384
Innodb_pages_created 388
Innodb_pages_read 232676
Innodb_pages_written 10525
Innodb_row_lock_current_waits 0
Innodb_row_lock_time 0
Innodb_row_lock_time_avg 0
Innodb_row_lock_time_max 0
Innodb_row_lock_waits 0
Innodb_rows_deleted 605
Innodb_rows_inserted 33914
Innodb_rows_read 125144394
Innodb_rows_updated 20612
Innodb_num_open_files 5200
Innodb_truncated_status_writes 0
Innodb_available_undo_logs 128
Key_blocks_not_flushed 0
Key_blocks_unused 13396
Key_blocks_used 3
Key_read_requests 6
Key_reads 3
Key_write_requests 0
Key_writes 0
Locked_connects 0
Max_execution_time_exceeded 0
Max_execution_time_set 0
Max_execution_time_set_failed 0
Max_used_connections 14
Max_used_connections_time 10/01/20 15:50
Not_flushed_delayed_rows 0
Ongoing_anonymous_transaction_count 0
Open_files 0
Open_streams 0
Open_table_definitions 3464
Open_tables 5200
Opened_files 337104
Opened_table_definitions 140571
Opened_tables 76095
Performance_schema_accounts_lost 0
Performance_schema_cond_classes_lost 0
Performance_schema_cond_instances_lost 0
Performance_schema_digest_lost 0
Performance_schema_file_classes_lost 0
Performance_schema_file_handles_lost 0
Performance_schema_file_instances_lost 0
Performance_schema_hosts_lost 0
Performance_schema_index_stat_lost 0
Performance_schema_locker_lost 0
Performance_schema_memory_classes_lost 0
Performance_schema_metadata_lock_lost 0
Performance_schema_mutex_classes_lost 0
Performance_schema_mutex_instances_lost 0
Performance_schema_nested_statement_lost 0
Performance_schema_prepared_statements_lost 0
Performance_schema_program_lost 0
Performance_schema_rwlock_classes_lost 0
Performance_schema_rwlock_instances_lost 0
Performance_schema_session_connect_attrs_lost 0
Performance_schema_socket_classes_lost 0
Performance_schema_socket_instances_lost 0
Performance_schema_stage_classes_lost 0
Performance_schema_statement_classes_lost 0
Performance_schema_table_handles_lost 0
Performance_schema_table_instances_lost 0
Performance_schema_table_lock_stat_lost 0
Performance_schema_thread_classes_lost 0
Performance_schema_thread_instances_lost 0
Performance_schema_users_lost 0
Prepared_stmt_count 0
Qcache_free_blocks 1
Qcache_free_memory 16760152
Qcache_hits 0
Qcache_inserts 0
Qcache_lowmem_prunes 0
Qcache_not_cached 184049
Qcache_queries_in_cache 0
Qcache_total_blocks 1
Queries 687716
Questions 684326
Rsa_public_key <removed>
Select_full_join 2827
Select_full_range_join 319
Select_range 56255
Select_range_check 1525
Select_scan 156904
Slave_open_temp_tables 0
Slow_launch_threads 0
Slow_queries 0
Sort_merge_passes 0
Sort_range 61935
Sort_rows 116417
Sort_scan 99600
Table_locks_immediate 458
Table_locks_waited 0
Table_open_cache_hits 381570
Table_open_cache_misses 76095
Table_open_cache_overflows 70888
Tc_log_max_pages_used 0
Tc_log_page_size 0
Tc_log_page_waits 0
Threads_cached 7
Threads_connected 3
Threads_created 14
Threads_running 1
Uptime 424288
Uptime_since_flush_status 424288
Short answer: If you are not swapping and not crashing, there is nothing to worry about. But, since OOM is killing it, then something needs to be tuned lower.
Long answer...
Change swappiness to 1. (It may be defaulted to 60.)
For only 4GB of RAM, do not set innodb_buffer_pool_size to 75-80% of RAM as someone else suggested. You will run out of RAM. Swapping is terrible for performance. Leave it at 1G for now. And this assumes you do not have any other applications running on the machine.
The buffer_pool grows but does not shrink. It is reused. It is a "cache" for blocks of data and indexes of the various tables you are working on.
It sounds like 400MB is chewed up by performance_schema. If you are not using that, turn it off. If you are using it, then lower the buffer_pool to 1000M to make room for PS.
table_open_cache = 5200 -- Do you have thousands of tables? Perhaps 1000 would be safer.
Dozens, even hundreds, of databases is not a problem. table_open_cache is a cache, so it does not need to be as large as the number of tables you have. But, since there are multiple entries for one table when multiple connections are looking at that table, it can be too small.
For further analysis, please provide the info discussed here: http://mysql.rjweb.org/doc.php/mysql_analysis#tuning I will see if there are further clues in the VARIABLES and GLOBAL STATUS.
1K qps is moderately busy (~70th percentile); 10K gets more exciting. Since you seem to have bursts of activity, perhaps you are hitting 10K?
I am not a fan of "throwing hardware at a problem".
An analysis of the settings
Observations:
* Version: 5.7.28-0ubuntu0.16.04.2
* 4 GB of RAM
* Uptime = 4d 21:51:28
* Are you sure this was a SHOW GLOBAL STATUS ?
* You are not running on Windows.
* Running 64-bit version
* You appear to be running entirely (or mostly) InnoDB.
The More Important Issues:
Do not use LOCK TABLES / UNLOCK TABLES with InnoDB. Use transactions. (Or, let's discuss why you are using them.)
innodb_buffer_pool_size = 1G -- or lower if you have a lot of other apps running -- Caution: 1G would make the OOM issue worse, so don't do this until figuring out the OOM problem.
Your system seems to be rather lightly loaded -- except for the number of tables that are open. Can you elaborate on what the app does?
Possibly a lot of inefficient queries. Set long_query_time = 1 and turn on the slowlog.
Details and other observations:
( (key_buffer_size / 0.20 + innodb_buffer_pool_size / 0.70) ) = ((16M / 0.20 + 128M / 0.70)) / 4096M = 6.4% -- Most of available ram should be made available for caching.
-- http://mysql.rjweb.org/doc.php/memory
( table_open_cache ) = 5,200 -- Number of table descriptors to cache
-- Several hundred is usually good.
( Table_open_cache_misses / (Table_open_cache_hits + Table_open_cache_misses) ) = 76,095 / (381570 + 76095) = 16.6% -- Effectiveness of table_open_cache.
-- Increase table_open_cache (now 5200) and check table_open_cache_instances (now 16).
( innodb_buffer_pool_size ) = 128M -- InnoDB Data + Index cache
-- 128M (an old default) is woefully small.
( Innodb_buffer_pool_read_ahead_evicted / Innodb_buffer_pool_read_ahead ) = 552 / 2174 = 25.4% -- Utility of read_ahead.
-- Turn off innodb_random_read_ahead (now OFF).
( Innodb_dblwr_pages_written/Innodb_pages_written ) = 5,776/10525 = 54.9% -- Seems like these values should be equal?
( Innodb_os_log_written / (Uptime / 3600) / innodb_log_files_in_group / innodb_log_file_size ) = 34,017,280 / (424288 / 3600) / 2 / 48M = 0.00287 -- Ratio
-- (see minutes)
( Uptime / 60 * innodb_log_file_size / Innodb_os_log_written ) = 424,288 / 60 * 48M / 34017280 = 10,462 -- Minutes between InnoDB log rotations Beginning with 5.6.8, this can be changed dynamically; be sure to also change my.cnf.
-- (The recommendation of 60 minutes between rotations is somewhat arbitrary.) Adjust innodb_log_file_size (now 50331648). (Cannot change in AWS.)
( innodb_flush_method ) = innodb_flush_method = -- How InnoDB should ask the OS to write blocks. Suggest O_DIRECT or O_ALL_DIRECT (Percona) to avoid double buffering. (At least for Unix.) See chrischandler for caveat about O_ALL_DIRECT
( innodb_flush_neighbors ) = 1 -- A minor optimization when writing blocks to disk.
-- Use 0 for SSD drives; 1 for HDD.
( innodb_io_capacity ) = 200 -- I/O ops per second capable on disk . 100 for slow drives; 200 for spinning drives; 1000-2000 for SSDs; multiply by RAID factor.
( innodb_print_all_deadlocks ) = innodb_print_all_deadlocks = OFF -- Whether to log all Deadlocks.
-- If you are plagued with Deadlocks, turn this on. Caution: If you have lots of deadlocks, this may write a lot to disk.
( character_set_server ) = character_set_server = utf8
-- Charset problems may be helped by setting character_set_server (now utf8) to utf8mb4. That is the future default.
( net_buffer_length / max_allowed_packet ) = 16,384 / 16M = 0.10%
( local_infile ) = local_infile = ON
-- local_infile (now ON) = ON is a potential security issue
( Select_scan / Com_select ) = 156,904 / 290121 = 54.1% -- % of selects doing full table scan. (May be fooled by Stored Routines.)
-- Add indexes / optimize queries
( innodb_autoinc_lock_mode ) = 1 -- Galera: desires 2 -- 2 = "interleaved"; 1 = "consecutive" is typical; 0 = "traditional".
-- Galera desires 2; 2 requires BINLOG_FORMAT=ROW or MIXED
( slow_query_log ) = slow_query_log = OFF -- Whether to log slow queries. (5.1.12)
( long_query_time ) = 10 -- Cutoff (Seconds) for defining a "slow" query.
-- Suggest 2
( log_slow_slave_statements ) = log_slow_slave_statements = OFF -- (5.6.11, 5.7.1) By default, replicated statements won't show up in the slowlog; this causes them to show.
-- It can be helpful in the slowlog to see writes that could be interfering with Slave reads.
( back_log ) = 80 -- (Autosized as of 5.6.6; based on max_connections)
-- Raising to min(150, max_connections (now 151)) may help when doing lots of connections.
You have the Query Cache half-off. You should set both query_cache_type = OFF and query_cache_size = 0 . There is (according to a rumor) a 'bug' in the QC code that leaves some code on unless you turn off both of those settings.
Abnormally small:
Com_insert = 4.6 /HR
Created_tmp_files = 0.051 /HR
Handler_write = 0.33 /sec
Innodb_buffer_pool_bytes_data = 299 /sec
Key_read_requests = 0.051 /HR
Key_reads+Key_writes + Innodb_pages_read+Innodb_pages_written+Innodb_dblwr_writes+Innodb_buffer_pool_pages_flushed = 0.6 /sec
Open_files = 0
Table_locks_immediate = 3.9 /HR
Abnormally large:
Com_unlock_tables = 0.25 /sec
Innodb_num_open_files = 5,200
Open_table_definitions = 3,464
Open_tables = 5,200
performance_schema_max_rwlock_classes = 50
Abnormal strings:
innodb_fast_shutdown = 1
optimizer_trace = enabled=off,one_line=off
optimizer_trace_features = greedy_search=on, range_optimizer=on, dynamic_range=on, repeated_subselect=on
require_secure_transport = ON
slave_rows_search_algorithms = TABLE_SCAN,INDEX_SCAN
Related
Single Table Queries Very Slow With Indexes MariaDB
I am trying to tune some slow running queries on MariaDB and have hit a brick wall. I mainly work with Postgres / Oracle and these queries times seem extremely slow to me, but I can't figure out what I'm missing. The queries in question (see below for examples) are mostly single table queries or with one join / subquery. The table in question has around 19million rows (26.5gb) and has fairly frequent writes. Table structure and indexes below: CREATE TABLE products_reviews ( id bigint(20) NOT NULL AUTO_INCREMENT , product_id int(11) NOT NULL DEFAULT 0 , name varchar(255) NOT NULL DEFAULT '' , rate tinyint(4) NOT NULL DEFAULT 0 , created_at datetime NOT NULL , posted_at date NOT NULL , site varchar(50) NOT NULL , review text NOT NULL , details text DEFAULT NULL , type smallint(6) NOT NULL DEFAULT 0 , notify smallint(6) NOT NULL DEFAULT 1 , notify_daily int(11) NOT NULL DEFAULT 1 , user_id int(11) DEFAULT NULL , updated_at datetime NOT NULL , admin_id int(11) DEFAULT NULL , status smallint(6) NOT NULL DEFAULT 0 , comment text NOT NULL , notified_at datetime NOT NULL , reply tinyint(4) NOT NULL DEFAULT 0 , syndicate varchar(100) NOT NULL , status_user tinyint(4) NOT NULL , reviewer_id varchar(100) NOT NULL DEFAULT '' , sentiment text DEFAULT NULL , sentiment_score float(5,2) NOT NULL DEFAULT 0.00 , ai text DEFAULT NULL , active tinyint(4) NOT NULL DEFAULT 1 , active_updated_at datetime NOT NULL DEFAULT current_timestamp() , review_translate text NOT NULL , price float(6,2) NOT NULL , tagging text NOT NULL , site_id int(11) NOT NULL , hash varchar(255) NOT NULL , PRIMARY KEY (id) , KEY created_at (created_at) , KEY posted_at (posted_at) , KEY site (site) , KEY product_id (product_id) , KEY admin_id (admin_id) , KEY type (type) , KEY notify (notify) , KEY active (active) , KEY admin_posted (admin_id,posted_at) , KEY reviewer_id (reviewer_id) , KEY idx_products_reviews_pspth (product_id,site,posted_at,type,hash) , KEY idx_products_reviews_pa (product_id,active) , KEY idx_products_reviews_product_posted (product_id,posted_at) , KEY idx_products_reviews_product_adminid_postedid (product_id,admin_id,posted_at) , KEY product_id_2 (product_id,site,active) ) ENGINE=InnoDB AUTO_INCREMENT=27316062 DEFAULT CHARSET=utf8 Mariadb settings below: alter_algorithm DEFAULT aria_block_size 8192 aria_checkpoint_interval 30 aria_checkpoint_log_activity 1048576 aria_encrypt_tables OFF aria_force_start_after_recovery_failures 0 aria_group_commit none aria_group_commit_interval 0 aria_log_file_size 1073741824 aria_log_purge_type immediate aria_max_sort_file_size 9223372036853727232 aria_page_checksum ON aria_pagecache_age_threshold 300 aria_pagecache_buffer_size 134217728 aria_pagecache_division_limit 100 aria_pagecache_file_hash_size 512 aria_recover_options BACKUP,QUICK aria_repair_threads 1 aria_sort_buffer_size 268434432 aria_stats_method nulls_unequal aria_sync_log_dir NEWFILE aria_used_for_temp_tables ON auto_increment_increment 1 auto_increment_offset 1 autocommit ON automatic_sp_privileges ON back_log 100 basedir /usr big_tables OFF binlog_annotate_row_events ON binlog_cache_size 32768 binlog_checksum CRC32 binlog_commit_wait_count 0 binlog_commit_wait_usec 100000 binlog_direct_non_transactional_updates OFF binlog_file_cache_size 16384 binlog_format MIXED binlog_optimize_thread_scheduling ON binlog_row_image FULL binlog_stmt_cache_size 32768 bulk_insert_buffer_size 8388608 check_constraint_checks ON column_compression_threshold 100 column_compression_zlib_level 6 column_compression_zlib_strategy DEFAULT_STRATEGY column_compression_zlib_wrap OFF completion_type NO_CHAIN concurrent_insert AUTO connect_timeout 10 core_file OFF date_format %Y-%m-%d datetime_format %Y-%m-%d %H:%i:%s deadlock_search_depth_long 15 deadlock_search_depth_short 4 deadlock_timeout_long 50000000 deadlock_timeout_short 10000 debug_no_thread_alarm OFF default_master_connection default_regex_flags default_storage_engine InnoDB default_tmp_storage_engine MyISAM default_week_format 0 delay_key_write ON delayed_insert_limit 100 delayed_insert_timeout 300 delayed_queue_size 1000 div_precision_increment 4 encrypt_binlog OFF encrypt_tmp_disk_tables OFF encrypt_tmp_files OFF enforce_storage_engine eq_range_index_dive_limit 0 error_count 0 event_scheduler OFF expensive_subquery_limit 100 expire_logs_days 7 explicit_defaults_for_timestamp OFF external_user extra_max_connections 1 extra_port 0 flush OFF flush_time 0 foreign_key_checks ON ft_boolean_syntax + -><()~*:""&| ft_max_word_len 84 ft_min_word_len 4 ft_query_expansion_limit 20 ft_stopword_file (built-in) general_log OFF group_concat_max_len 1048576 gtid_binlog_pos gtid_binlog_state gtid_current_pos gtid_domain_id 0 gtid_ignore_duplicates OFF gtid_pos_auto_engines gtid_seq_no 0 gtid_slave_pos gtid_strict_mode OFF have_compress YES have_crypt YES have_dynamic_loading YES have_geometry YES have_openssl YES have_profiling YES have_query_cache YES have_rtree_keys YES have_ssl DISABLED have_symlink YES histogram_size 0 histogram_type SINGLE_PREC_HB host_cache_size 633 identity 0 idle_readonly_transaction_timeout 0 idle_transaction_timeout 0 idle_write_transaction_timeout 0 ignore_builtin_innodb OFF ignore_db_dirs in_predicate_conversion_threshold 1000 in_transaction 0 init_connect init_file init_slave innodb_adaptive_flushing ON innodb_adaptive_flushing_lwm 10.000000 innodb_adaptive_hash_index ON innodb_adaptive_hash_index_parts 8 innodb_adaptive_max_sleep_delay 150000 innodb_autoextend_increment 64 innodb_autoinc_lock_mode 1 innodb_background_scrub_data_check_interval 3600 innodb_background_scrub_data_compressed OFF innodb_background_scrub_data_interval 604800 innodb_background_scrub_data_uncompressed OFF innodb_buf_dump_status_frequency 0 innodb_buffer_pool_chunk_size 134217728 innodb_buffer_pool_dump_at_shutdown ON innodb_buffer_pool_dump_now OFF innodb_buffer_pool_dump_pct 25 innodb_buffer_pool_filename ib_buffer_pool innodb_buffer_pool_instances 8 innodb_buffer_pool_load_abort OFF innodb_buffer_pool_load_at_startup ON innodb_buffer_pool_load_now OFF innodb_buffer_pool_size 68719476736 innodb_change_buffer_max_size 25 innodb_change_buffering all innodb_checksum_algorithm crc32 innodb_checksums ON innodb_cmp_per_index_enabled OFF innodb_commit_concurrency 0 innodb_compression_algorithm zlib innodb_compression_default OFF innodb_compression_failure_threshold_pct 5 innodb_compression_level 6 innodb_compression_pad_pct_max 50 innodb_concurrency_tickets 5000 innodb_data_file_path ibdata1:12M:autoextend innodb_data_home_dir innodb_deadlock_detect ON innodb_default_encryption_key_id 1 innodb_default_row_format dynamic innodb_disable_sort_file_cache OFF innodb_disallow_writes OFF innodb_doublewrite ON innodb_encrypt_log OFF innodb_encrypt_tables OFF innodb_encrypt_temporary_tables OFF innodb_encryption_rotate_key_age 1 innodb_encryption_rotation_iops 100 innodb_encryption_threads 0 innodb_fast_shutdown 1 innodb_fatal_semaphore_wait_threshold 600 innodb_file_format innodb_file_per_table ON innodb_fill_factor 100 innodb_flush_log_at_timeout 1 innodb_flush_log_at_trx_commit 1 innodb_flush_method fsync innodb_flush_neighbors 1 innodb_flush_sync ON innodb_flushing_avg_loops 30 innodb_force_load_corrupted OFF innodb_force_primary_key OFF innodb_force_recovery 0 innodb_ft_aux_table innodb_ft_cache_size 8000000 innodb_ft_enable_diag_print OFF innodb_ft_enable_stopword ON innodb_ft_max_token_size 84 innodb_ft_min_token_size 3 innodb_ft_num_word_optimize 2000 innodb_ft_result_cache_limit 2000000000 innodb_ft_server_stopword_table innodb_ft_sort_pll_degree 2 innodb_ft_total_cache_size 640000000 innodb_ft_user_stopword_table innodb_idle_flush_pct 100 innodb_immediate_scrub_data_uncompressed OFF innodb_io_capacity 1000 innodb_io_capacity_max 2000 innodb_large_prefix innodb_lock_schedule_algorithm fcfs innodb_lock_wait_timeout 50 innodb_locks_unsafe_for_binlog OFF innodb_log_buffer_size 16777216 innodb_log_checksums ON innodb_log_compressed_pages ON innodb_log_file_size 50331648 innodb_log_files_in_group 2 innodb_log_group_home_dir ./ innodb_log_optimize_ddl ON innodb_log_write_ahead_size 8192 innodb_lru_scan_depth 1024 innodb_max_dirty_pages_pct 75.000000 innodb_max_dirty_pages_pct_lwm 0.000000 innodb_max_purge_lag 0 innodb_max_purge_lag_delay 0 innodb_max_undo_log_size 10485760 innodb_monitor_disable innodb_monitor_enable innodb_monitor_reset innodb_monitor_reset_all innodb_old_blocks_pct 37 innodb_old_blocks_time 1000 innodb_online_alter_log_max_size 134217728 innodb_open_files 4096 innodb_optimize_fulltext_only OFF innodb_page_cleaners 4 innodb_page_size 16384 innodb_prefix_index_cluster_optimization OFF innodb_print_all_deadlocks OFF innodb_purge_batch_size 300 innodb_purge_rseg_truncate_frequency 128 innodb_purge_threads 4 innodb_random_read_ahead OFF innodb_read_ahead_threshold 56 innodb_read_io_threads 4 innodb_read_only OFF innodb_replication_delay 0 innodb_rollback_on_timeout OFF innodb_rollback_segments 128 innodb_scrub_log OFF innodb_scrub_log_speed 256 innodb_sort_buffer_size 1048576 innodb_spin_wait_delay 4 innodb_stats_auto_recalc ON innodb_stats_include_delete_marked OFF innodb_stats_method nulls_equal innodb_stats_modified_counter 0 innodb_stats_on_metadata OFF innodb_stats_persistent ON innodb_stats_persistent_sample_pages 20 innodb_stats_sample_pages 8 innodb_stats_traditional ON innodb_stats_transient_sample_pages 8 innodb_status_output OFF innodb_status_output_locks OFF innodb_strict_mode OFF innodb_sync_array_size 1 innodb_sync_spin_loops 30 innodb_table_locks ON innodb_temp_data_file_path ibtmp1:12M:autoextend innodb_thread_concurrency 0 innodb_thread_sleep_delay 10000 innodb_tmpdir innodb_undo_directory ./ innodb_undo_log_truncate OFF innodb_undo_logs 128 innodb_undo_tablespaces 0 innodb_use_atomic_writes ON innodb_use_native_aio ON innodb_version 10.3.21 innodb_write_io_threads 4 insert_id 0 interactive_timeout 3600 join_buffer_size 1048576 join_buffer_space_limit 2097152 join_cache_level 2 keep_files_on_create OFF key_buffer_size 67108864 key_cache_age_threshold 300 key_cache_block_size 1024 key_cache_division_limit 100 key_cache_file_hash_size 512 key_cache_segments 0 large_files_support ON large_page_size 0 large_pages OFF last_gtid last_insert_id 0 lc_messages en_US lc_messages_dir lc_time_names en_US license GPL local_infile ON lock_wait_timeout 86400 locked_in_memory OFF log_bin OFF log_bin_basename log_bin_compress OFF log_bin_compress_min_len 256 log_bin_index log_bin_trust_function_creators OFF log_disabled_statements sp log_error /var/log/mariadb/mariadb.log log_output FILE log_queries_not_using_indexes OFF log_slave_updates OFF log_slow_admin_statements ON log_slow_disabled_statements sp log_slow_filter admin,filesort,filesort_on_disk,filesort_priority_queue,full_join,full_scan,query_cache,query_cache_miss,tmp_table,tmp_table_on_disk log_slow_rate_limit 1 log_slow_slave_statements ON log_slow_verbosity log_tc_size 24576 log_warnings 2 long_query_time 1.000000 low_priority_updates OFF lower_case_file_system OFF lower_case_table_names 0 master_verify_checksum OFF max_allowed_packet 67108864 max_binlog_cache_size 18446744073709547520 max_binlog_size 1073741824 max_binlog_stmt_cache_size 18446744073709547520 max_connect_errors 10000 max_connections 600 max_delayed_threads 20 max_digest_length 1024 max_error_count 64 max_heap_table_size 67108864 max_insert_delayed_threads 20 max_join_size 18446744073709551615 max_length_for_sort_data 1024 max_long_data_size 67108864 max_prepared_stmt_count 16382 max_recursive_iterations 4294967295 max_relay_log_size 1073741824 max_seeks_for_key 4294967295 max_session_mem_used 9223372036854775807 max_sort_length 1024 max_sp_recursion_depth 0 max_statement_time 0.000000 max_tmp_tables 32 max_user_connections 0 max_write_lock_count 4294967295 metadata_locks_cache_size 1024 metadata_locks_hash_instances 8 min_examined_row_limit 0 mrr_buffer_size 262144 multi_range_count 256 myisam_block_size 1024 myisam_data_pointer_size 6 myisam_max_sort_file_size 9223372036853727232 myisam_mmap_size 18446744073709551615 myisam_recover_options BACKUP,QUICK myisam_repair_threads 1 myisam_sort_buffer_size 134217728 myisam_stats_method NULLS_UNEQUAL myisam_use_mmap OFF mysql56_temporal_format ON net_buffer_length 16384 net_read_timeout 30 net_retry_count 10 net_write_timeout 60 open_files_limit 65535 optimizer_prune_level 1 optimizer_search_depth 62 optimizer_selectivity_sampling_limit 100 optimizer_switch index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on optimizer_use_condition_selectivity 1 performance_schema OFF performance_schema_accounts_size -1 performance_schema_digests_size -1 performance_schema_events_stages_history_long_size -1 performance_schema_events_stages_history_size -1 performance_schema_events_statements_history_long_size -1 performance_schema_events_statements_history_size -1 performance_schema_events_waits_history_long_size -1 performance_schema_events_waits_history_size -1 performance_schema_hosts_size -1 performance_schema_max_cond_classes 80 performance_schema_max_cond_instances -1 performance_schema_max_digest_length 1024 performance_schema_max_file_classes 50 performance_schema_max_file_handles 32768 performance_schema_max_file_instances -1 performance_schema_max_mutex_classes 200 performance_schema_max_mutex_instances -1 performance_schema_max_rwlock_classes 40 performance_schema_max_rwlock_instances -1 performance_schema_max_socket_classes 10 performance_schema_max_socket_instances -1 performance_schema_max_stage_classes 160 performance_schema_max_statement_classes 200 performance_schema_max_table_handles -1 performance_schema_max_table_instances -1 performance_schema_max_thread_classes 50 performance_schema_max_thread_instances -1 performance_schema_session_connect_attrs_size -1 performance_schema_setup_actors_size 100 performance_schema_setup_objects_size 100 performance_schema_users_size -1 pid_file /var/run/mariadb/mariadb.pid plugin_dir /usr/lib64/mysql/plugin/ plugin_maturity gamma port 3306 preload_buffer_size 32768 profiling OFF profiling_history_size 15 progress_report_time 5 protocol_version 10 proxy_protocol_networks proxy_user pseudo_slave_mode OFF pseudo_thread_id 1852681 query_alloc_block_size 16384 query_cache_limit 1048576 query_cache_min_res_unit 4096 query_cache_size 1048576 query_cache_strip_comments OFF query_cache_type OFF query_cache_wlock_invalidate OFF query_prealloc_size 24576 rand_seed1 93838501 rand_seed2 36662033 range_alloc_block_size 4096 read_binlog_speed_limit 0 read_buffer_size 1048576 read_only OFF read_rnd_buffer_size 1048576 relay_log relay_log_basename relay_log_index relay_log_info_file relay-log.info relay_log_purge ON relay_log_recovery OFF relay_log_space_limit 17179869184 replicate_annotate_row_events ON replicate_do_db replicate_do_table replicate_events_marked_for_skip REPLICATE replicate_ignore_db replicate_ignore_table replicate_wild_do_table replicate_wild_ignore_table report_host report_password report_port 3306 report_user rowid_merge_buff_size 8388608 secure_auth ON secure_file_priv secure_timestamp NO server_id 1 session_track_schema ON session_track_state_change OFF session_track_system_variables autocommit,character_set_client,character_set_connection,character_set_results,time_zone session_track_transaction_info OFF skip_external_locking ON skip_name_resolve ON skip_networking OFF skip_parallel_replication OFF skip_replication OFF skip_show_database OFF slave_compressed_protocol OFF slave_ddl_exec_mode IDEMPOTENT slave_domain_parallel_threads 0 slave_exec_mode STRICT slave_load_tmpdir /san/svc-fs/mysqltmp slave_max_allowed_packet 1073741824 slave_net_timeout 60 slave_parallel_max_queued 131072 slave_parallel_mode conservative slave_parallel_threads 0 slave_parallel_workers 0 slave_run_triggers_for_rbr NO slave_skip_errors OFF slave_sql_verify_checksum ON slave_transaction_retries 10 slave_transaction_retry_errors 1213,1205 slave_transaction_retry_interval 0 slave_type_conversions slow_launch_time 2 slow_query_log ON slow_query_log_file /san/svc-fs/mysqllogs/slow-log socket /san/svc-fs/mysql/mysql.sock sort_buffer_size 1048576 sql_auto_is_null OFF sql_big_selects ON sql_buffer_result OFF sql_log_bin ON sql_log_off OFF sql_mode NO_ENGINE_SUBSTITUTION sql_notes ON sql_quote_show_create ON sql_safe_updates OFF sql_select_limit 18446744073709551615 sql_slave_skip_counter 0 sql_warnings OFF ssl_ca ssl_capath ssl_cert ssl_cipher ssl_crl ssl_crlpath ssl_key standard_compliant_cte ON storage_engine InnoDB stored_program_cache 256 strict_password_validation ON sync_binlog 0 sync_frm ON sync_master_info 10000 sync_relay_log 10000 sync_relay_log_info 10000 system_time_zone CST system_versioning_alter_history ERROR system_versioning_asof DEFAULT table_definition_cache 4096 table_open_cache 4096 table_open_cache_instances 8 tcp_keepalive_interval 0 tcp_keepalive_probes 0 tcp_keepalive_time 0 thread_cache_size 16 thread_concurrency 10 thread_handling one-thread-per-connection thread_pool_idle_timeout 60 thread_pool_max_threads 65536 thread_pool_oversubscribe 3 thread_pool_prio_kickup_timer 1000 thread_pool_priority auto thread_pool_size 16 thread_pool_stall_limit 500 thread_stack 299008 time_format %H:%i:%s time_zone SYSTEM timed_mutexes OFF timestamp 1644789513.087889 tmp_disk_table_size 18446744073709551615 tmp_memory_table_size 33554432 tmp_table_size 33554432 tmpdir /san/svc-fs/mysqltmp transaction_alloc_block_size 8192 transaction_prealloc_size 4096 tx_isolation REPEATABLE-READ tx_read_only OFF unique_checks ON updatable_views_with_limit YES use_stat_tables NEVER userstat OFF version 10.3.21-MariaDB-log version_comment MariaDB Server version_compile_machine x86_64 version_compile_os Linux version_malloc_library jemalloc 3.6.0-0-g46c0af68bd248b04df75e4f92d5fb804c3d75340 version_source_revision e5e5877740f248de848219ee3a1d2881cd5c5b82 version_ssl_library OpenSSL 1.0.2k-fips 26 Jan 2017 wait_timeout 600 warning_count 0 wsrep_osu_method TOI wsrep_auto_increment_control ON wsrep_causal_reads OFF wsrep_certification_rules strict wsrep_certify_nonpk ON wsrep_cluster_address wsrep_cluster_name my_wsrep_cluster wsrep_convert_lock_to_trx OFF wsrep_data_home_dir /san/svc-fs/mysql/ wsrep_dbug_option wsrep_debug OFF wsrep_desync OFF wsrep_dirty_reads OFF wsrep_drupal_282555_workaround OFF wsrep_forced_binlog_format NONE wsrep_gtid_domain_id 0 wsrep_gtid_mode OFF wsrep_load_data_splitting ON wsrep_log_conflicts OFF wsrep_max_ws_rows 0 wsrep_max_ws_size 2147483647 wsrep_mysql_replication_bundle 0 wsrep_node_address wsrep_node_incoming_address AUTO wsrep_notify_cmd wsrep_on OFF wsrep_patch_version wsrep_25.24 wsrep_provider none wsrep_provider_options wsrep_recover OFF wsrep_reject_queries NONE wsrep_replicate_myisam OFF wsrep_restart_slave OFF wsrep_retry_autocommit 1 wsrep_slave_fk_checks ON wsrep_slave_uk_checks OFF wsrep_slave_threads 1 wsrep_sst_auth wsrep_sst_donor wsrep_sst_donor_rejects_queries OFF wsrep_sst_method rsync wsrep_sst_receive_address AUTO wsrep_start_position 00000000-0000-0000-0000-000000000000:-1 wsrep_sync_wait 0 The queries filters can be selected on the front end by a user so the where clause can vary a bit. They will all contain a product_id at least. The speed to read from disk seems absurdly slow for the number of rows being fetched. Example queries: This one takes 400seconds to return Edit - Below query is in an incorrect format which must have happened when creating the post. Original is below SELECT SQL_NO_CACHE pr.rate as star, pr.product_id, pr.site, COUNT(pr.id) AS count FROM products_reviews pr JOIN products p ON p.id = pr.product_id AND pr.active > 0 AND pr.posted_at >= '2020-10-26' AND pr.posted_at <= '2022-01-24 23:59' AND pr.admin_id = 3598 GROUP BY pr.rate, pr.product_id, pr.site; SELECT rate as star, product_id, site, COUNT(id) AS count FROM products_reviews WHERE product_id IN (SELECT id FROM products WHERE admin_id = 3598) AND active >0 AND posted_at >= '2020-10-26' AND posted_at <= '2022-01-24 23:59' AND admin_id = 3598 GROUP BY rate, product_id, site Explain plan { "query_block": { "select_id": 1, "filesort": { "sort_key": "products_reviews.rate, products_reviews.product_id, products_reviews.site", "temporary_table": { "table": { "table_name": "products_reviews", "access_type": "range", "possible_keys": [ "posted_at", "product_id", "admin_id", "active", "admin_posted", "idx_products_reviews_pspth", "idx_products_reviews_pa", "idx_products_reviews_product_posted", "idx_products_reviews_product_adminid_postedid", "product_id_2", "idx_products_aaprps_covering", "idx_products_aprps_covering_t" ], "key": "idx_products_aaprps_covering", "key_length": "6", "used_key_parts": ["admin_id", "active"], "rows": 1826162, "filtered": 100, "attached_condition": "products_reviews.admin_id = 3598 and products_reviews.active > 0 and products_reviews.posted_at >= '2020-10-26' and products_reviews.posted_at <= '2022-01-24 23:59'", "using_index": true }, "table": { "table_name": "products", "access_type": "eq_ref", "possible_keys": ["PRIMARY", "id", "admin_id"], "key": "PRIMARY", "key_length": "8", "used_key_parts": ["id"], "ref": ["metabase.products_reviews.product_id"], "rows": 1, "filtered": 100, "attached_condition": "products.admin_id = 3598 and products_reviews.product_id = products.`id`" } } } } } I ran profiling on the transaction and the whole time is spent on "Sending Data". Here is a second query, this one takes around 32 seconds. SELECT site, MIN(posted_at) as posted_at, AVG(IF(rate>0, rate, NULL)) as rate, COUNT(IF(type=0, 1, NULL)) as count, COUNT(IF(type=0 AND syndicate='', 1, NULL)) as count_ns, AVG(IF(rate>0 AND syndicate='', rate, NULL)) as rate_ns, COUNT(IF(type=1, 1, NULL)) as count_qe FROM products_reviews WHERE product_id = '24828' AND active >0 GROUP BY site Explain Plan { "query_block": { "select_id": 1, "table": { "table_name": "products_reviews", "access_type": "ref", "possible_keys": [ "product_id", "active", "idx_products_reviews_pspth", "idx_products_reviews_pa", "idx_products_reviews_product_posted", "idx_products_reviews_product_adminid_postedid", "product_id_2" ], "key": "product_id_2", "key_length": "4", "used_key_parts": ["product_id"], "ref": ["const"], "rows": 6575, "filtered": 100, "attached_condition": "products_reviews.product_id <=> '24828' and products_reviews.active > 0" } } { "query_block": { "select_id": 1, "table": { "table_name": "products_reviews", "access_type": "ref", "possible_keys": [ "product_id", "active", "idx_products_reviews_pspth", "idx_products_reviews_pa", "idx_products_reviews_product_posted", "idx_products_reviews_product_adminid_postedid", "product_id_2" ], "key": "product_id_2", "key_length": "4", "used_key_parts": ["product_id"], "ref": ["const"], "rows": 6575, "filtered": 100, "attached_condition": "products_reviews.product_id <=> '24828' and products_reviews.active > 0" } } } Possibly partially related to cardinality. Here's a count of rows, distinct product_id and distinct posted_at. count(*) 19128090 count(distinct(product_id)) 28821 count(distinct(posted_at)) 7551 The server has 96gb RAM and a 480GB SATA SSD. The buffer pool settings look well optimized to me. I tried increasing innodb_io_capacity but that had a negative impact. If there is nothing I can do to speed up the queries with regards query tuning or parameter tuning, I wondered about keeping the table in memory at all times. They seem to get flushed at least once a day (probably around the time backups are taken). Would it be sensible to have a job that runs once every couple of hours to select * from the table? Many thanks.
It's a good question you ask. My answer has a few dimensions. Server provisioning: Your machine is adequate, and possibly overprovisioned. You have allocated 2/3 of your server's RAM to your 64GiB InnoDB buffer pool (innodb_buffer_pool_size) and that's probably enough to hold your tables. You could allocate another 8 - 12 GiB to it and still have RAM left over for your server's other functions. But buffer pool size is almost certainly not your issue. Many indexes: You have quite a few single-column indexes. Are you sure they are all needed? Generally speaking, we create indexes to support particular query patterns, not because they might be helpful someday. If you can drop some of your indexes, do so. And, indexes slow down INSERTs and UPDATEs because both the table data and indexes are affected. Which brings us to ... Frequent updates: It's possible that your update operations slow down the reporting-style queries you showed us in your question because the server is struggling to give consistent results (using locks) as updates happen. Try giving this SQL statement right before your too-slow query. SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED; This causes a "dirty read". It cuts down on locking, but gives you the chance you'll get an older version of rows that are being actively updated. That's usually no problem for reporting-style queries. Try it and see how much it helps. Equality and range filters, covering BTREE indexes. Consider your first query, repeated here: SELECT SQL_NO_CACHE pr.rate as star, pr.product_id, pr.site, COUNT(pr.id) AS count FROM products_reviews pr JOIN products p ON p.id = pr.product_id AND pr.active > 0 AND pr.posted_at >= '2020-10-26' AND pr.posted_at <= '2022-01-24 23:59' AND pr.admin_id = 3598 GROUP BY pr.rate, pr.product_id, pr.site; You filter product_reviews on admin_id for equality, then active and posted at for ranges, then you look up rows in products, then group by rate, product_id, and site. Try using this so-called covering index. CREATE INDEX rate_product_site_rollup ON products_review (admin_id, posted_at, active, rate, product_id, site); It contains the data your query needs from the products_review table. To satisfy the query, the database can random-access the index to the first eligible row (admin_id = nnnn and the first eligible posted_at row. It can then scan the index sequentially to filter out active <= 0 rows. Finally, your GROUP BY columns are there already sorted in an order suitable for quick grouping. You might consider a similar covering index for your second query. (Some makes and versions of database servers allow INCLUDE(col, col, col) clauses in index declarations, but not MariaDB / MySQL. INCLUDE is very useful for covering indexes, but including the columns in the index works too.) More than one range filter: BTREE indexes do their fastest work when you only have one range filter in your query. If your business rules allowed you to filter on pr.active = 1 then this index would satisfy your query even faster. CREATE INDEX rate_product_site_rollup ON products_review (admin_id, active, posted_at, rate, product_id, site); Extraneous JOIN: You JOIN to your products table, but don't use any columns from it. So the JOIN serves only one purpose: to exclude reviews that have no matching product. Is this step necessary? Note: pr.posted_at < '2022-01-24' + INTERVAL 1 DAY, with <, is a bit more reliable on the almost-midnight edge case than pr.posted_at <= '2022-01-24 23:59'
`products is only sort of used. If you don't really need it, get rid of it. I see two things that can matter: If there is no matching row from products the JOIN will avoid including it. If there are multiple rows in products, then the COUNT will increase. Replace JOIN products p ON p.id = pr.product_id AND with WHERE As a rule: Use ON to specify how the tables are related. Use WHERE to specify which rows to keep. Another INDEX tip: When you need INDEX(a,b), you can do without INDEX(a). I am thinking of (admin_id, posted_at) If active is only "0" or "1", then use AND active = 1, plus change to INDEX(admin_id, active, posted_at) "indexes could only contain one equality operator" -- The rule is more like "Indexes should contain only one range operator, and it needs to be last". (Note: "covering" is a deliberate exception.) (I agree that the 'covering' index may help, but I generally avoid indexes with lots of columns.) I have the master of that MariaDB link (that RLOG mentioned); it has been updated a few times here: http://mysql.rjweb.org/doc.php/index_cookbook_mysql
MySQL 5.5 innoDB writes drop, scripts slow down and locks increase
I have a database that I do INSERTS into by a python script that calls various API's and runs on a cron. There are also SELECT statements that look at previous values in the table in order to create averages based off the current and previous data. Everything runs fine for a day or two, however after that the database seems to enter a form of contention where the sites will drop, locks will increase and the scripts slow down in their performance. I do deletes after all scripts complete (Never at the same time to avoid locking) in order to truncate data and keep the database small ensuring it doesn't reach it's buffer_pool_size limit. Previously I had a crazy query_cache_size of 2048M for a DB that is heavy on writes, I've changed that to 10M recently and the query_cache_limit to 256K since then I've done no extra changes. There are a lot of mixed reviews online about what can be done to optimise this, most of my tables have an index because it is also heavy on SELECT statements as well as writes. The below is my my.cnf file, I'm hoping someone might be able to help with if there's any setting here that might be ubsurd and should be changed. I'm running on mysql Ver 14.14 Distrib 5.5.62, for debian-linux-gnu (x86_64) and using innoDB. Below is the my.cnf file. Appreciate the help. thread_cache_size was set to 100 as max_used_connections tends to sit on 128. Threads_connected tends to range from 90-120. The server is a 4-core 32gb RAM server from AWS r5.xlarge # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/lib/mysql/mysql.sock host = 127.0.0.1 # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/lib/mysql/mysql.sock nice = 0 [mysqld] # # * Basic Settings # user = mysql pid-file = /var/lib/mysql/mysql.pid #/var/run/mysqld/mysqld.pid socket = /var/lib/mysql/mysql.sock #/var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp lc-messages-dir = /usr/share/mysql skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = 0.0.0.0 key_buffer_size = 256M table_cache = 16394 thread_cache_size = 100 innodb_file_per_table = ON ## Per-Thread Buffers * (max_connections) = total per-thread mem usage thread_stack = 256K #default: 32bit: 192K, 64bit: 256K sort_buffer_size = 2M #default: 2M, larger may cause perf issues read_buffer_size = 2M #default: 128K, change in increments of 4K read_rnd_buffer_size = 2M #default: 256K join_buffer_size = 2M #default: 128K binlog_cache_size = 256K #default: 32K, size of buffer to hold TX queries ## Query Cache query_cache_size = 10M #global buffer query_cache_limit = 256K #max query result size to put in cache ## Connections max_connections = 500 # was 400 #multiplier for memory usage via per-thread buffers max_connect_errors = 100 # was 200 #default: 10 concurrent_insert = 2 #default: 1, 2: enable insert for all instances connect_timeout = 60 #default -5.1.22: 5, +5.1.22: 10 ## Table and TMP settings max_heap_table_size = 2048M #recommend same size as tmp_table_size bulk_insert_buffer_size = 2048M #recommend same size as tmp_table_size tmp_table_size = 2048M #recommend 1G min ## MyISAM Engine key_buffer = 2M #global buffer myisam_sort_buffer_size = 256M #index buffer size for creating/altering indexes myisam_max_sort_file_size = 512M #max file size for tmp table when creating/alering indexes ## InnoDB IO settings - 5.5.x and greater innodb_write_io_threads = 64 # Apr7 innodb_read_io_threads = 64 # Apr7 #innodb_log_file_size = 3G innodb_buffer_pool_size = 22G #global buffer innodb-buffer-pool-instances = 20 innodb_additional_mem_pool_size = 24M #global buffer # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 # # Error log - should be very few entries. # log_error = /var/log/mysql/error.log # # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log expire_logs_days = 10 max_binlog_size = 100M #binlog_do_db = include_database_name #binlog_ignore_db = include_database_name # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/ Complete GLOBAL STATUS after the servers been up for over 24 hours and has now hit the contention state. Variable_name Value Aborted_clients 8659 Aborted_connects 0 Binlog_cache_disk_use 0 Binlog_cache_use 0 Binlog_stmt_cache_disk_use 0 Binlog_stmt_cache_use 0 Bytes_received 10528823106 Bytes_sent 11879095113 Com_admin_commands 114321 Com_assign_to_keycache 0 Com_alter_db 0 Com_alter_db_upgrade 0 Com_alter_event 0 Com_alter_function 0 Com_alter_procedure 0 Com_alter_server 0 Com_alter_table 0 Com_alter_tablespace 0 Com_analyze 0 Com_begin 0 Com_binlog 0 Com_call_procedure 0 Com_change_db 2494 Com_change_master 0 Com_check 0 Com_checksum 0 Com_commit 21669803 Com_create_db 0 Com_create_event 0 Com_create_function 0 Com_create_index 0 Com_create_procedure 0 Com_create_server 0 Com_create_table 0 Com_create_trigger 0 Com_create_udf 0 Com_create_user 0 Com_create_view 0 Com_dealloc_sql 0 Com_delete 57847 Com_delete_multi 2 Com_do 0 Com_drop_db 0 Com_drop_event 0 Com_drop_function 0 Com_drop_index 0 Com_drop_procedure 0 Com_drop_server 0 Com_drop_table 0 Com_drop_trigger 0 Com_drop_user 0 Com_drop_view 0 Com_empty_query 0 Com_execute_sql 0 Com_flush 1 Com_grant 0 Com_ha_close 0 Com_ha_open 0 Com_ha_read 0 Com_help 0 Com_insert 10384315 Com_insert_select 4493 Com_install_plugin 0 Com_kill 0 Com_load 0 Com_lock_tables 0 Com_optimize 0 Com_preload_keys 0 Com_prepare_sql 0 Com_purge 0 Com_purge_before_date 0 Com_release_savepoint 0 Com_rename_table 0 Com_rename_user 0 Com_repair 0 Com_replace 0 Com_replace_select 0 Com_reset 0 Com_resignal 0 Com_revoke 0 Com_revoke_all 0 Com_rollback 0 Com_rollback_to_savepoint 0 Com_savepoint 0 Com_select 31617317 Com_set_option 585637 Com_signal 0 Com_show_authors 0 Com_show_binlog_events 0 Com_show_binlogs 0 Com_show_charsets 0 Com_show_collations 0 Com_show_contributors 0 Com_show_create_db 0 Com_show_create_event 0 Com_show_create_func 0 Com_show_create_proc 0 Com_show_create_table 0 Com_show_create_trigger 0 Com_show_databases 1 Com_show_engine_logs 0 Com_show_engine_mutex 0 Com_show_engine_status 4415 Com_show_events 0 Com_show_errors 0 Com_show_fields 7780 Com_show_function_status 0 Com_show_grants 0 Com_show_keys 0 Com_show_master_status 0 Com_show_open_tables 0 Com_show_plugins 0 Com_show_privileges 0 Com_show_procedure_status 0 Com_show_processlist 0 Com_show_profile 0 Com_show_profiles 0 Com_show_relaylog_events 0 Com_show_slave_hosts 0 Com_show_slave_status 0 Com_show_status 4416 Com_show_storage_engines 0 Com_show_table_status 0 Com_show_tables 2492 Com_show_triggers 0 Com_show_variables 9040 Com_show_warnings 11880457 Com_slave_start 0 Com_slave_stop 0 Com_stmt_close 48226 Com_stmt_execute 90467 Com_stmt_fetch 0 Com_stmt_prepare 48354 Com_stmt_reprepare 0 Com_stmt_reset 0 Com_stmt_send_long_data 218 Com_truncate 16 Com_uninstall_plugin 0 Com_unlock_tables 0 Com_update 11304832 Com_update_multi 0 Com_xa_commit 0 Com_xa_end 0 Com_xa_prepare 0 Com_xa_recover 0 Com_xa_rollback 0 Com_xa_start 0 Compression ON Connections 692888 Created_tmp_disk_tables 969524 Created_tmp_files 152 Created_tmp_tables 1104523 Delayed_errors 0 Delayed_insert_threads 0 Delayed_writes 0 Flush_commands 1 Handler_commit 74944534 Handler_delete 9802964 Handler_discover 0 Handler_prepare 0 Handler_read_first 333333 Handler_read_key 61866586 Handler_read_last 3454093 Handler_read_next 13704879326 Handler_read_prev 2773935641 Handler_read_rnd 39932346 Handler_read_rnd_next 9899032663 Handler_rollback 170160 Handler_savepoint 0 Handler_savepoint_rollback 0 Handler_update 40464627 Handler_write 180607735 Innodb_buffer_pool_pages_data 768282 Innodb_buffer_pool_bytes_data 12587532288 Innodb_buffer_pool_pages_dirty 10741 Innodb_buffer_pool_bytes_dirty 175980544 Innodb_buffer_pool_pages_flushed 39908997 Innodb_buffer_pool_pages_free 563241 Innodb_buffer_pool_pages_misc 110237 Innodb_buffer_pool_pages_total 1441760 Innodb_buffer_pool_read_ahead_rnd 0 Innodb_buffer_pool_read_ahead 24195 Innodb_buffer_pool_read_ahead_evicted 0 Innodb_buffer_pool_read_requests 61256179019 Innodb_buffer_pool_reads 519946 Innodb_buffer_pool_wait_free 0 Innodb_buffer_pool_write_requests 307699280 Innodb_data_fsyncs 22277830 Innodb_data_pending_fsyncs 1 Innodb_data_pending_reads 0 Innodb_data_pending_writes 0 Innodb_data_read 10761654272 Innodb_data_reads 656718 Innodb_data_writes 59599294 Innodb_data_written 1327119237120 Innodb_dblwr_pages_written 39909506 Innodb_dblwr_writes 2757000 Innodb_have_atomic_builtins ON Innodb_log_waits 0 Innodb_log_write_requests 22935831 Innodb_log_writes 16721934 Innodb_os_log_fsyncs 16783015 Innodb_os_log_pending_fsyncs 1 Innodb_os_log_pending_writes 0 Innodb_os_log_written 19349207552 Innodb_page_size 16384 Innodb_pages_created 111573 Innodb_pages_read 656709 Innodb_pages_written 39909506 Innodb_row_lock_current_waits 0 Innodb_row_lock_time 78010 Innodb_row_lock_time_avg 84 Innodb_row_lock_time_max 3217 Innodb_row_lock_waits 926 Innodb_rows_deleted 9802964 Innodb_rows_inserted 10494572 Innodb_rows_read 25829527401 Innodb_rows_updated 13355863 Innodb_truncated_status_writes 0 Key_blocks_not_flushed 0 Key_blocks_unused 1674 Key_blocks_used 21 Key_read_requests 358190032 Key_reads 0 Key_write_requests 116148559 Key_writes 0 Last_query_cost 0.000000 Max_used_connections 247 Not_flushed_delayed_rows 0 Open_files 48 Open_streams 0 Open_table_definitions 325 Open_tables 597 Opened_files 3878714 Opened_table_definitions 341 Opened_tables 620 Performance_schema_cond_classes_lost 0 Performance_schema_cond_instances_lost 0 Performance_schema_file_classes_lost 0 Performance_schema_file_handles_lost 0 Performance_schema_file_instances_lost 0 Performance_schema_locker_lost 0 Performance_schema_mutex_classes_lost 0 Performance_schema_mutex_instances_lost 0 Performance_schema_rwlock_classes_lost 0 Performance_schema_rwlock_instances_lost 0 Performance_schema_table_handles_lost 0 Performance_schema_table_instances_lost 0 Performance_schema_thread_classes_lost 0 Performance_schema_thread_instances_lost 0 Prepared_stmt_count 128 Qcache_free_blocks 0 Qcache_free_memory 0 Qcache_hits 0 Qcache_inserts 0 Qcache_lowmem_prunes 0 Qcache_not_cached 0 Qcache_queries_in_cache 0 Qcache_total_blocks 0 Queries 88430604 Questions 88219702 Rpl_status AUTH_MASTER Select_full_join 3100 Select_full_range_join 806 Select_range 14288643 Select_range_check 0 Select_scan 225040 Slave_heartbeat_period 0.000 Slave_open_temp_tables 0 Slave_received_heartbeats 0 Slave_retried_transactions 0 Slave_running OFF Slow_launch_threads 0 Slow_queries 18 Sort_merge_passes 147 Sort_range 7993917 Sort_rows 23603619 Sort_scan 934553 Ssl_accept_renegotiates 0 Ssl_accepts 0 Ssl_callback_cache_hits 0 Ssl_cipher Ssl_cipher_list Ssl_client_connects 0 Ssl_connect_renegotiates 0 Ssl_ctx_verify_depth 0 Ssl_ctx_verify_mode 0 Ssl_default_timeout 0 Ssl_finished_accepts 0 Ssl_finished_connects 0 Ssl_session_cache_hits 0 Ssl_session_cache_misses 0 Ssl_session_cache_mode NONE Ssl_session_cache_overflows 0 Ssl_session_cache_size 0 Ssl_session_cache_timeouts 0 Ssl_sessions_reused 0 Ssl_used_session_cache_entries 0 Ssl_verify_depth 0 Ssl_verify_mode 0 Ssl_version Table_locks_immediate 67102620 Table_locks_waited 0 Tc_log_max_pages_used 0 Tc_log_page_size 0 Tc_log_page_waits 0 Threads_cached 58 Threads_connected 102 Threads_created 674 Threads_running 5 Uptime 84415 Uptime_since_flush_status 84415
MySQL TokuDB engine using too much CPU
I have converted tables of a database from InnoDB to TokuDB and i noticed that with TokuDB, reads are using way too much CPU. Why is this? To be more specific, the server with TokuDB tables is a slave of a server with InnoDB which is part of the PXC. The slave just used regular percona server and not PXC. But the slave seems to be using way too much CPU and i do not know why? Below is my my.cnf config: [client] port = 3306 socket = /var/run/mysqld/mysqld.sock [mysqld_safe] thp-setting=never socket = /var/run/mysqld/mysqld.sock nice = 0 flush_caches numa_interleave core-file-size = unlimited open_files_limit = 1024 [mysqld] back_log = 65535 bind-address = 0.0.0.0 binlog_format = ROW character_set_server = utf8 collation_server = utf8_general_ci core_file basedir = /usr datadir = /var/lib/mysql #default_storage_engine = InnoDB enforce-gtid-consistency = 1 expand_fast_index_creation = 1 expire_logs_days = 7 gtid_mode = ON innodb_autoinc_lock_mode = 2 innodb_buffer_pool_instances = 1 innodb_buffer_pool_populate = 1 innodb_buffer_pool_size = 512M innodb_data_file_path = ibdata1:64M;ibdata2:64M:autoextend innodb_file_format = Barracuda innodb_file_per_table innodb_force_recovery = 1 innodb_flush_log_at_trx_commit = 2 innodb_flush_method = O_DIRECT innodb_io_capacity = 1600 innodb_large_prefix innodb_locks_unsafe_for_binlog = 1 innodb_log_file_size = 64M innodb_print_all_deadlocks = 1 innodb_read_io_threads = 64 innodb_stats_on_metadata = FALSE innodb_support_xa = FALSE innodb_write_io_threads = 64 lc-messages-dir = /usr/share/mysql log-bin = mysqld-bin log-queries-not-using-indexes log-slave-updates long_query_time = 1 master_info_repository = TABLE max_allowed_packet = 64M max_connect_errors = 4294967295 max_connections = 2500 max_user_connections = 2550 min_examined_row_limit = 1000 open_files_limit = 1024 port = 3306 relay_log_info_repository = TABLE relay-log-recovery = TRUE relay-log-recovery = 1 skip-external-locking skip-name-resolve slave_parallel_workers = 8 slow_query_log = 1 slow_query_log_timestamp_always = 1 socket = /var/run/mysqld/mysqld.sock table_open_cache = 4096 thread_cache = 1024 tmpdir = /srv/tmp transaction_isolation = REPEATABLE-READ updatable_views_with_limit = 0 user = mysql wait_timeout = 60 server-id = 2 # TokuDB fine tuning default_storage_engine = TokuDB tokudb_analyze_time = 5 #tokudb_cache_size = 6G tokudb_directio = 1 tokudb_commit_sync = 0 tokudb_fsync_log_period = 1000 tokudb_load_save_space =1 tokudb_alter_print_error=0 tokudb_block_size = 4MB tokudb_bulk_fetch = 1 tokudb_disable_slow_alter = 1 tokudb_last_lock_timeout = empty tokudb_row_format = tokudb_quicklz #tokudb_data_dir = /var/lib/tokudb [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M !includedir /etc/mysql/conf.d/ The following replication message was being reported by our monitoring system xymon when tokudb_cache_size when initially set to 80% of total RAM. 2016-02-25 16:42:04 9604 [Warning] Neither --relay-log nor --relay-log-index were used; so replication may break when this MySQL server acts as a slave and has his hostname changed!! Please use '--relay-log=db-kdb-slave-6-relay-bin' to avoid this problem. 2016-02-25 16:42:05 9604 [Warning] Recovery from master pos 552554502 and file mysqld-bin.001163. Previous relay log pos and relay log file had been set to 552554714, ./db-kdb-slave-6-relay-bin.002933 respectively. 2016-02-25 16:42:05 9604 [Warning] Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information. ------More info about the Master server running InnoDB and part of PXC----------- ## Results from top top - 10:05:12 up 14 days, 7:56, 2 users, load average: 2.16, 2.31, 2.39 Tasks: 413 total, 1 running, 412 sleeping, 0 stopped, 0 zombie %Cpu(s): 8.9 us, 0.6 sy, 0.0 ni, 89.9 id, 0.3 wa, 0.0 hi, 0.2 si, 0.0 st KiB Mem: 65704012 total, 63553216 used, 2150796 free, 169832 buffers KiB Swap: 975868 total, 809892 used, 165976 free. 16304268 cached Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2485 mysql 20 0 60.146g 0.045t 2.612g S 314.9 73.3 27762:43 mysqld ## disk info george#db-erp-3:~$ df -h Filesystem Size Used Avail Use% Mounted on udev 32G 8.0K 32G 1% /dev tmpfs 6.3G 1.2M 6.3G 1% /run /dev/sda2 274G 2.1G 258G 1% / none 4.0K 0 4.0K 0% /sys/fs/cgroup none 5.0M 0 5.0M 0% /run/lock none 32G 0 32G 0% /run/shm none 100M 0 100M 0% /run/user /dev/nvme0n1p1 1.1T 542G 503G 52% /srv na1:/vol/yphome 4.5T 3.7T 875G 82% /net/account ## Memory info george#db-erp-3:~$ free -g total used free shared buffers cached Mem: 62 60 2 0 0 15 -/+ buffers/cache: 44 17 Swap: 0 0 0 george#db-erp-3:~$ ## Database info +--------------------+----------------------+ | Data Base Name | Data Base Size in MB | +--------------------+----------------------+ | information_schema | 0.00976563 | | dberp | 347143.32031250 | | mysql | 2.11562061 | | performance_schema | 0.00000000 | +--------------------+----------------------+ 4 rows in set (0.13 sec) +--------------------+----------------------+------------------+ | Data Base Name | Data Base Size in MB | Free Space in MB | +--------------------+----------------------+------------------+ | information_schema | 0.00976563 | 0.00000000 | | dberp | 347143.32031250 | 6270.00000000 | | mysql | 2.11562061 | 4.00199127 | | performance_schema | 0.00000000 | 0.00000000 | +--------------------+----------------------+------------------+ 4 rows in set (0.03 sec)
Your CPU will be higher for reads because TokuDB data needs to be decompressed to be used. Also, if this slave is processing any activity from the master than it's also doing compression for the insert/update/delete activity. Couple of ideas. 1. Reduce the value of tokudb_block_size. While 4MB is great for compression it means that your point queries need to decompress a lot more data than they have to. Try using 256KB and see how CPU and performance changes. You might have to rebuild your slave to accomplish this easily (I'm now over a year away from working at TokuDB). 2. Look at your tokudb_cache_size. It defaults to 50% of RAM, but if nothing else is on this server you should up it to somewhere between 75% and 80%. This will mean less reads and decompression since more data will be in your cache.
MySQL query performance issue with MyISAM table
Folks I have a table( billing_data) with about 60 million records. The table engine is MyISAM. We have a stored procedure that will read csv file and dump in temp table every 10-15 mins and then it will be inserted in this table( billing_data). There are lot of records being inserted in this table. we are trying to run the query as below on the same table( plus the other tables in join) to generate the report. "select b.destination,b.release_cause_protocol_stack,b.binary_value_protocol_stack,b.release_cause from billing_datas b inner join (select id from carriermasters where id in (99, 100, 101) ) c1 on b.carrierid_customer=c1.idinner join (select id from technicalprofiles where id in (83, 274, 84, 416)) t1 on b.technical_profileid_customer=t1.id inner join (select trunk from trunks where trunk in (90409, 90310, 30230, 30313) ) tr1 on b.origination_trunkid=tr1.trunk inner join (select id from carriermasters where id in (214, 215, 59, 60, 62, 292, 63, 216, 64, 61, 217, 274, 58) ) c2 on b.carrierid_supplier=c2.id inner join (select id from technicalprofiles where id in (223, 55, 224, 56, 225, 57, 226, 58, 227, 228, 229, 230, 393, 394, 395, 59, 231, 232, 233, 460, 234)) t2 on b.technical_profileid_supplier=t2.id inner join (select trunk from trunks where trunk in (90106, 30249, 90249, 30250, 90250, 90445, 30409, 90446, 30410, 30294, 90363, 30293, 90293, 30175, 30146, 90146, 90435, 90049, 30177, 90294, 90130, 30130, 90189, 30145, 90145, 90389, 30400, 90429, 90121, 90159)) tr2 on b.supplierid=tr2.trunk where b.start_time_date between '2013-08-02 00:00:00' and '2013-08-02 23:59:59' order by b.start_time_date asc" NOw the scenario is a) if we stop the cron job to insert the data in the billing_datas table, then the above query takes about more than 40 mins. b) if the cron job is running ( inserting the data from the file) to the temp table and then to billing_data. At that time the above query will run forever. I m not sure where i m getting wrong. we also checked the indexes and its fine. Mysql query : show variables automatic_sp_privileges ON back_log 50 big_tables OFF binlog_cache_size 32768 binlog_direct_non_transactional_updates OFF binlog_format STATEMENT bulk_insert_buffer_size 8388608 completion_type 0 concurrent_insert 1 connect_timeout 10 default_week_format 0 delay_key_write ON delayed_insert_limit 100 delayed_insert_timeout 300 delayed_queue_size 1000 div_precision_increment 4 engine_condition_pushdown ON event_scheduler OFF flush OFF flush_time 0 foreign_key_checks ON ft_query_expansion_limit 20 ignore_builtin_innodb OFF innodb_adaptive_hash_index ON innodb_additional_mem_pool_size 1048576 innodb_autoextend_increment 8 innodb_autoinc_lock_mode 1 innodb_buffer_pool_size 8388608 innodb_checksums ON innodb_commit_concurrency 0 innodb_concurrency_tickets 500 innodb_data_file_path ibdata1:10M:autoextend innodb_data_home_dir innodb_doublewrite ON innodb_fast_shutdown 1 innodb_file_io_threads 4 innodb_file_per_table OFF innodb_flush_log_at_trx_commit 1 innodb_flush_method innodb_force_recovery 0 innodb_lock_wait_timeout 50 innodb_locks_unsafe_for_binlog OFF innodb_log_buffer_size 1048576 innodb_log_file_size 5242880 innodb_log_files_in_group 2 innodb_max_dirty_pages_pct 90 innodb_max_purge_lag 0 innodb_mirrored_log_groups 1 innodb_open_files 300 innodb_rollback_on_timeout OFF innodb_stats_method nulls_equal innodb_stats_on_metadata ON innodb_support_xa ON innodb_sync_spin_loops 20 innodb_table_locks ON innodb_thread_concurrency 8 innodb_thread_sleep_delay 10000 innodb_use_legacy_cardinality_algorithm ON insert_id 0 interactive_timeout 28800 join_buffer_size 131072 keep_files_on_create OFF key_buffer_size 8384512 key_cache_age_threshold 300 key_cache_block_size 1024 key_cache_division_limit 100 large_files_support ON large_page_size 0 large_pages OFF last_insert_id 0 local_infile ON locked_in_memory OFF log OFF log_bin OFF log_bin_trust_function_creators OFF log_bin_trust_routine_creators OFF long_query_time 10 low_priority_updates OFF max_allowed_packet 1048576 max_binlog_cache_size 1.84467E+19 max_binlog_size 1073741824 max_connect_errors 10 max_connections 151 max_delayed_threads 20 max_error_count 64 max_heap_table_size 16777216 max_insert_delayed_threads 20 max_join_size 1.84467E+19 max_length_for_sort_data 1024 max_long_data_size 1048576 max_prepared_stmt_count 16382 max_relay_log_size 0 max_seeks_for_key 1.84467E+19 max_sort_length 1024 max_sp_recursion_depth 0 max_tmp_tables 32 max_user_connections 0 max_write_lock_count 1.84467E+19 min_examined_row_limit 0 multi_range_count 256 myisam_data_pointer_size 6 myisam_max_sort_file_size 9.22337E+18 myisam_mmap_size 1.84467E+19 myisam_recover_options OFF myisam_repair_threads 1 myisam_sort_buffer_size 8388608 myisam_stats_method nulls_unequal myisam_use_mmap OFF net_buffer_length 16384 net_read_timeout 30 net_retry_count 10 net_write_timeout 60 open_files_limit 1024 optimizer_prune_level 1 optimizer_search_depth 62 optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on preload_buffer_size 32768 pseudo_thread_id 7256 query_alloc_block_size 8192 query_cache_limit 1048576 query_cache_min_res_unit 4096 query_cache_size 0 query_cache_type ON query_cache_wlock_invalidate OFF query_prealloc_size 8192 range_alloc_block_size 4096 read_buffer_size 131072 read_only OFF read_rnd_buffer_size 262144 skip_external_locking ON slow_launch_time 2 sort_buffer_size 2097144 sql_auto_is_null ON sql_big_selects ON sql_big_tables OFF sql_buffer_result OFF sql_log_bin ON sql_log_off OFF sql_log_update ON sql_low_priority_updates OFF sql_max_join_size 1.84467E+19 sql_quote_show_create ON sql_safe_updates OFF sql_select_limit 1.84467E+19 storage_engine MyISAM sync_binlog 0 sync_frm ON table_definition_cache 256 table_lock_wait_timeout 50 table_open_cache 64 table_type MyISAM thread_cache_size 0 thread_handling one-thread-per-connection thread_stack 262144 timed_mutexes OFF tmp_table_size 16777216 transaction_alloc_block_size 8192 transaction_prealloc_size 4096 unique_checks ON updatable_views_with_limit YES version 05/01/69 version_compile_os redhat-linux-gnu wait_timeout 28800
SELECT b.destination , b.release_cause_protocol_stack , b.binary_value_protocol_stack , b.release_cause FROM billing_datas b JOIN carriermasters customer ON b.carrierid_customer = customer.id JOIN technicalprofiles tpc ON b.technical_profileid_customer = tpc.id JOIN trunks kc ON b.origination_trunkid = kc.trunk JOIN carriermasters supplier ON b.carrierid_supplier = supplier.id JOIN technicalprofiles tps ON b.technical_profileid_supplier = tps.id JOIN trunks ks ON b.supplierid = ks.trunk WHERE b.start_time_date BETWEEN '2013-08-02 00:00:00' AND '2013-08-02 23:59:59' AND customer.id IN (99, 100, 101) AND tpc.id IN (83, 274, 84, 416) AND kc.trunk IN (90409, 90310, 30230, 30313) AND supplier.id IN (214, 215, 59, 60, 62, 292, 63, 216, 64, 61, 217, 274, 58) AND tps.id IN (223, 55, 224, 56, 225, 57, 226, 58, 227, 228, 229, 230, 393, 394, 395, 59, 231, 232, 233, 460, 234) AND ks.trunk IN (90106, 30249, 90249, 30250, 90250, 90445, 30409, 90446, 30410, 30294, 90363, 30293, 90293, 30175, 30146, 90146, 90435, 90049, 30177, 90294, 90130, 30130, 90189, 30145, 90145, 90389, 30400, 90429, 90121, 90159) ORDER BY b.start_time_date ASC;
InnoDB insert count slow down
I batch insert to mysql innoDB table continuously, insert per second ratio is slow down. Some behaviour are - If shutdown data inserter (java) application, mysql do some i/o operation for a while. - Add some insert then shutdown mysql server, shutdown operation duration is too long. If start and stop mysql without any insertion, start and stop operation so fast. - Insert speed is not (so much) depend on data amount on table. If restart mysql server, insert per second is similar to last restart insert per second value. I read some comment on forum, do not add continuosly, have gap between 2 insertions. Is it meaningful? Why sql is slow down? query SHOW VARIABLES LIKE 'inno%' result is below innodb_adaptive_flushing = ON innodb_adaptive_hash_index = ON innodb_additional_mem_pool_size = 20971520 innodb_autoextend_increment = 8 innodb_autoinc_lock_mode = 1 innodb_buffer_pool_instances = 1 innodb_buffer_pool_size = 268435456 innodb_change_buffering = all innodb_checksums = ON innodb_commit_concurrency = 0 innodb_concurrency_tickets = 500 innodb_data_file_path = ibdata1:50M:autoextend innodb_data_home_dir = innodb_doublewrite = ON innodb_fast_shutdown = 1 innodb_file_format = Barracuda innodb_file_format_check = ON innodb_file_format_max = Antelope innodb_file_per_table = ON innodb_flush_log_at_trx_commit = 2 innodb_flush_method = O_DSYNC innodb_force_recovery = 0 innodb_io_capacity = 200 innodb_lock_wait_timeout = 50 innodb_locks_unsafe_for_binlog = OFF innodb_log_buffer_size = 8388608 innodb_log_file_size = 268435456 innodb_log_files_in_group = 2 innodb_log_group_home_dir = ./ innodb_max_dirty_pages_pct = 75 innodb_max_purge_lag = 0 innodb_mirrored_log_groups = 1 innodb_old_blocks_pct = 37 innodb_old_blocks_time = 0 innodb_open_files = 300 innodb_purge_batch_size = 20 innodb_purge_threads = 0 innodb_read_ahead_threshold = 56 innodb_read_io_threads = 4 innodb_replication_delay = 0 innodb_rollback_on_timeout = OFF innodb_spin_wait_delay = 6 innodb_stats_on_metadata = ON innodb_stats_sample_pages = 8 innodb_strict_mode = ON innodb_support_xa = ON innodb_sync_spin_loops = 30 innodb_table_locks = ON innodb_thread_concurrency = 0 innodb_thread_sleep_delay = 10000 innodb_use_native_aio = OFF innodb_use_sys_malloc = ON innodb_version = 1.1.1 innodb_write_io_threads = 4 Thanks
InnoDB works by default in autocommit mode, which means every insert requires writing to disk twice. Using extended inserts (a.k.a. multi-row inserts) and enclosing several consecutive inserts into a transaction increases performance.
Slow down reason is insert operation stored on to cache (dirty page) and periodically written hard-drive. Until dirty page memory is full insert operations are fast then cache is full and insert speed bottleneck disc written (I/O). You can use below sql to show dirty page size "Modified db pages" show engine innodb status