Why MySQL server took time compare than MySQL inside wamp ?
Machine 1 installed MySQL 5.6.17(inside the wamp)
Machine 2 installed MySQL 5.7.24(separate server)
Both machines are same configuration and same OS.
I imported same DB dump file to Machine1 and Machine2.
Now I execute query (the query get data from 6 join tables) and return 400 rows.
Took time:
Machine 1 (5.6.17) inside wamp- Below 30 sec's
Machine 2 (5.7.24) - Morethan 230 sec's
Shall I use MySQL(wamp) instead of MySQL server?
I think MySQL server need to increase Innodb_bufferpool_size on my.ini which located from C;\Program Data (Default hidden folder)
Default Innodb_bufferpool_size is 8M
innodb_buffer_pool_size: This is a very important setting to look immediate after the installation using InnoDB. The InnoDB is the buffer pool where the data is indexed the cached, which has a very large possible size that will make sure and use the memory no the disk space for most of the read-write operations, generally the size of InnoDB values are 5-6GB for 8GB RAM.
Fix: Increase innodb_buffer_pool_size
innodb_buffer_pool_size=356M
Related
I tried to migrate the database of existing application from MySQL 5.6 to MySQL 8.0
I have created the backup .sql file from old engine and deplayed it to new 8.0 server - I received no errors , no warnings - process finished successfully.
BUT - my database size was 62 MB in MySQL 5.6 and when I moved it to MySQL 8.0 size changed to 56 MB. I have tried to check which tables where different and noticed that in some tabled the number of rows decreased.
Can anyone tell me why such strange thing happend? Why database size and row number decreased- even throw the process finished without errors and warnings.
Are there some important thinks that I need to know in migration process - that will allow me not to loose any data?
Make sure you have few things listed out.
1) Total number of tables in 5.6
2) highest rows tables.
First try to restore dump in same 5.6 version, double check above information.
decreasing size in few MB's is very common because of compression and restoration is different at another server.
All you need to make sure total number of rows should not decreased.
I don't know what's going on. My server has been fine for probably a year. Now I'm having a severe problem with MariaDB/MySQL. The DB server keeps crashing. When it does and I bring it back online I get errors, several tables are marked crashed and I have to repair them. Here are the server specs...
CloudLinux Server release 6.6 installed on Centos 6.5 (x64)
WHM/Cpanel 11.50.1 Build 1 (Current)
MariaDB 10.0.21
RAM: 3,820MB (3750MB+ in use)
Swap: 1,023MB (1,023MB in use)
4 Cores (Low idle load)
Available Disk Space: 26GB
I suspect it has to do with memory. Here's a memory alert I get in WHM:
Here's what I get when I try to visit a web site on my server that uses MySQL (As expected):
Warning: mysql_connect(): Connection refused in /home/mysite/public_html/index.php on line 19
Unable to connect to server.
Here's a link to the main error log of my database server (Too much to post here): http://wikisend.com/download/182056/proton.myserver.com.err.txt
This is what happens when I restart my database server from WHM. Each time I restart the db server, random tables are marked as crashed. Sometimes a lot of tables, sometimes just a few and then I have to repair them:
Here is the contents of the /etc/my.cnf file:
root#proton [~]# cat /etc/my.cnf
[mysqld]
default-storage-engine=MyISAM
innodb_file_per_table=1
max_allowed_packet=268435456
open_files_limit=10000
innodb_buffer_pool_size=123731968
The only thing I've tried to fix this is setting this option in WHM:
I only have a handful of sites on the server. Any help is greatly appreciated.
SHOW VARIABLES LIKE '%buffer%';
Do you have other products running in the same VM/server? How much of the 3750MB are they using? Consider increasing RAM as a quick fix. Otherwise, lets look for what is chewing up RAM.
You are probably no using any InnoDB tables? If not then change this to 0:
innodb_buffer_pool_size=123731968
For MyISAM, the most important factor is key_buffer_size; it should be no more than about 500M for your case.
What is WHM?
Abrupt stops of mysql (for any reason) leads to the need to REPAIR MyISAM tables ("marked crashed"). (Consider moving to InnoDB to avoid this recurring nuisance.)
The below command takes 2-3 seconds in a Linux MySQL 5.6 server running Php 5.4
exec("mysql --host=$db_host --user=$db_user --password=$db_password $db_name < $sql_file");
On windows with similar configuration it takes 10-15 seconds. The windows machine has a lot more ram (16gb) and similar hard drive. I installed MySQL 5.6 and made no configuration changes. This is on windows server 2012.
What are configurations I can change to fix this?
The database file creates about 40 innodb tables with very minimal inserts.
EDIT: Here is the file I am running:
https://www.dropbox.com/s/uguzgbbnyghok0o/database_14.4.sql?dl=0
UPDATE: On windows 8 and 7 it was 3 seconds. But on windows server 2012 it is 15+ seconds. I disabled System center 2012 and that made no difference.
UPDATE 2:
I also tried killing almost every service except for mysql and IIS and it still performed slowly. Is there something in windows server 2012 that causes this to be slow?
Update 3
I tried disable write cache buffer flush and performance is now great.
I didn't have to do this on other machines I tested with. Does this indicate a bottleneck With how disk is setup?
https://social.technet.microsoft.com/Forums/windows/en-US/282ea0fc-fba7-4474-83d5-f9bbce0e52ea/major-disk-speed-improvement-disable-write-cache-buffer-flushing?forum=w7itproperf
That is why we call it LAMP stack and no doubt why it is so popular mysql on windows vs Linux. But that has more to do more with stability and safety. Performance wise the difference should be minimal. While a Microsoft Professional can best tune the Windows Server explicitly for MySQL by enabling and disabling the services, but we would rather be interested to see the configuration of your my.ini. So what could be the contributing factors w.r.t Windows on MySQL that we should consider
The services and policies in Windows is sometimes a big impediment to performance because of all sorts of restrictions and protections.
We should also take into account the Apache(httpd.conf) and PHP(php.ini) configuration as MySQL is so tightly coupled with them.
Antivirus : Better disable this when benchmarking about performance
Must consider these parameters in my.ini as here you have 40 Innodb tables
innodb_buffer_pool_size, innodb_flush_log_at_trx_commit, query_cache_size, innodb_flush_method, innodb_log_file_size, innodb_file_per_table
For example: If file size of ib_logfile0 = 524288000, Then
524288000/1048576 = 500, Hence innodb_log_file_size should be 500M
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DIRECT
https://dev.mysql.com/doc/refman/5.1/en/innodb-tuning.html
When importing data into InnoDB, make sure that MySQL does not have autocommit mode enabled because that requires a log flush to disk for every insert
SET autocommit=0;
Most importantly innodb_flush_log_at_trx_commit as in this case it is about importing database. Setting this to '2' form '1' (default)hm can be a big performance booster specially during data import as log buffer will be flushed to OS file cache on every transaction commit
For reference :
https://dev.mysql.com/doc/refman/5.5/en/optimizing-innodb-bulk-data-loading.html
https://dba.stackexchange.com/a/72766/60318
http://kvz.io/blog/2009/03/31/improve-mysql-insert-performance/
Lastly, based on this
mysql --host=$db_host --user=$db_user --password=$db_password $db_name < $sql_file
If the mysqldump (.sql) file is not residing in the same host where you are importing, performance will be slow. Consider to copy the (.sql) file exactly in the server where you need to import the database, then try importing without --host option.
Windows is slower at creating files, period. 40 InnoDB tables involves 40 or 80 file creations. Since they are small InnoDB tables, you may as well set innodb_file_per_table=OFF before doing the CREATEs, thereby needing only 40 file creations.
Good practice in MySQL is to create tables once, and not be creating/dropping tables frequently. If your application is designed to do lots of CREATEs, we should focus on that. (Note that, even on Linux, table create time is non-trivial.)
If these are temporary tables... 5.7 will have significant changes that will improve the performance (on either OS) in this area. 5.7 is on the cusp of being GA.
(RAM size is irrelevant in this situation.)
I am currently using MySQL. I have noticed several times my front application runs slow after some usage. when i checked server status in MySQL workbench. I have noticed that innodb buffer usage was going to 100% . so I increased parameter innodb_buffer_pool_size to 1G in my.ini file of xampp. but innodb is not flushing the buffer and application runs slow after some time. is there any other parameters to change as-well?
consider using a size for innodb_buffer_pool_size of 70%-80% of available ram. Depending on how big your dataset is, you should increase the size.
I have a server with 12GB RAM, and max_heap_table_size in my.cnf is set to 6GB. ("max_heap_table_size=6442450944"). I restarted the MySQL server after setting this.
The trouble is, whenever my table gets to just 2GB during inserts I get error "table full". Why is it not letting me add more than 2GB worth of data? (The 2GB figure is what is shown as the size in phpMyAdmin)
A 32 bit MySQL server (or any 32 bit application for that matter) only have 2-3Gb(Depending on the OS, etc.) of virtual memory available, and thus can't address more memory. You need a 64 bit OS, and a 64 bit MySQL server to take advantage of more memory.