My issue is, my website open too many connections in mysql server this is hanged my website and also generate many requests on apache. i have installed the apache module mod-evasive and mod-security i have also empty the iptables rules basically i am using amazon ec2 so it gives security ip i have blocked all outbound and inbound i have opened only 443,80 and ssh 22 port only but still when i take netstat it shows
netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n
4 --0.0.0.0
4 ---119.159.195.199
25 ---54.69.254.252
374 ---
on above my question is why my server 374 apache connection on ::1:80 how can block this or reduce this
mysql connection stat are
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| Connections | 5208 |
| Threads_cached | 0 |
| Threads_connected | 54 |
| Threads_created | 5207 |
| Threads_running | 54 |
+-------------------+-------+
5 rows in set (0.00 sec)
my second question is why my sql connections is increasing.
Please any one help me i will really appreciated.
Related
I need to download locally (macOS BigSur) a large dataset (millions of rows) from an AWS RDS database (MySQL 5.7).
Thanks to this great post I am able to connect and download on my machine some data into a csv file:
mysql --host=$HOST --user $USER --password=$PASSWORD --database=$DATABASE --port=$PORT --batch \
--quick -e "$QUERY" \
| sed $'s/\\t/","/g;s/^/"/;s/$/"/;s/\\n//g' > $FILE_PATH
However, if I extend my query to thousands of records, after few seconds the process stops and the csv ends up truncated (literally the last written row is truncated half way), so I assume there is some kind of stream or timeout or buffer issue.
mysql> SHOW VARIABLES LIKE '%timeout';
+-----------------------------+----------+
| Variable_name | Value |
+-----------------------------+----------+
| connect_timeout | 10 |
| delayed_insert_timeout | 300 |
| have_statement_timeout | YES |
| innodb_flush_log_at_timeout | 1 |
| innodb_lock_wait_timeout | 50 |
| innodb_rollback_on_timeout | OFF |
| interactive_timeout | 28800 |
| lock_wait_timeout | 31536000 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| rpl_stop_slave_timeout | 31536000 |
| slave_net_timeout | 60 |
| wait_timeout | 28800 |
+-----------------------------+----------+
Since the command does stops after ~10sec I assume it depends on the connect_timeout value. However I tried setting it with SET ##GLOBAL.connect_timeout=7200 but I get a permission error. I tried adding the --connect-timeout=7200 parameter on the command, but it does not work (which strikes me the most).
Running the query (limited to ~250k rows) on my client (SequelAce) it runs fine, so I can exclude issues with the data or the the SQL script itself.
Any ideas or suggestions?
Are there better tools for the job maybe?
We have problem to run php script via crontab. There are around 70 lines that run scripts installed in different virtual servers. When few lines are executed everything is working but when we have more some of them are not executed.
First we thought that this is crontab issue, but then we figure out that we are getting error from the script 'Error msg: Unable to connect to the database'. Just to let you now this script allow applications, that we have installed on our VPS to execut of the system's scheduled sending script (so you we can schedule our emails to be sent at a later date) on our server.
By getting this error we know that problem exist in the mysql engine. We are not mysql experts so maybe someone knows what to do with this. Here are few outputs from our mysql.
Uptime: 80832 Threads: 60 Questions: 4116373
Slow queries: 2067 Opens: 69721 Flush tables: 2
Open tables: 400 Queries per second avg: 50.925
and
+--------------------------+--------+
| Variable_name | Value |
+--------------------------+--------+
| Aborted_connects | 64 |
| Connections | 671995 |
| Max_used_connections | 215 |
| Ssl_client_connects | 0 |
| Ssl_connect_renegotiates | 0 |
| Ssl_finished_connects | 0 |
| Threads_connected | 60 |
+--------------------------+--------+
Do you see something suspicious here? Connections are opened only on localhost. In /etc/my.cnf there is a setup
bind-address = 127.0.0.1
When I run the command show processlist; I get details of the connections made to the server. Here are the connection details of my MySQL server,
mysql> show processlist;
+------+-----------------+----------------------+-------------+---------+----------+------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+------+-----------------+----------------------+-------------+---------+----------+------------------------+------------------+
| 1 | event_scheduler | localhost | NULL | Daemon | 13200075 | Waiting on empty queue | NULL |
| 4212 | root | localhost | NULL | Query | 0 | init | show processlist |
| 4214 | root | xxx.xx.xxx.xxx:50197 | testmysqldb | Sleep | 1 | | NULL |
| 4215 | root | xxx.xx.xxx.xxx:50198 | testmysqldb | Sleep | 3 | | NULL |
+------+-----------------+----------------------+-------------+---------+----------+------------------------+------------------+
What does the "number" after the term hostname and a colon (:) mean? It generally appears when a remote connection is made, on Linux and appears even for local connection on Windows.
Thanks in Advance!!
It's the client's port number used for the connection.
"xxx.xx.xxx.xxx:50197" means that there's an open connection from IP address "xxx.xx.xxx.xxx" and port 50197, towards your MySQL server (probably on port 3306.)
This is the client's TCP Port.
You connect to the server for example on default port 3306 but the client uses a different port on its side of the connection. This port is listed there.
It's client port number i.e. a connection gets open between two processes (on the same host or physically apart) using sockets - Socket is host_ip:port_num
So when we connect to a mysql (on same machine - localhost or remote server) a connection is opened i.e.
client_ip:xxxxx --> mysql_ip:3306 (3306 is default for Mysql, can use other port as well)
Example:
xxx.xx.xxx.xxx:50197
We send query and receive response from the mysql (mysql_ip:3306) at client_ip:50197
Can anyone tell me how can I kill all the sleeping processes?
I searched for it and I found that we can do it by command
mk-kill --match-command Sleep --kill --victims all --interval 10
I connected the DB server(Linux) but I find the message that command not found.
I tried to connect via MYSQL administrator and it doesn't say that command not found but also doesn't executes the query , just says you have an SQl error
login to Mysql as admin:
mysql -uroot -ppassword;
And than run command:
mysql> show processlist;
You will get something like below :
+----+-------------+--------------------+----------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+--------------------+----------+---------+------+-------+------------------+
| 49 | application | 192.168.44.1:51718 | XXXXXXXX | Sleep | 183 | | NULL ||
| 55 | application | 192.168.44.1:51769 | XXXXXXXX | Sleep | 148 | | NULL |
| 56 | application | 192.168.44.1:51770 | XXXXXXXX | Sleep | 148 | | NULL |
| 57 | application | 192.168.44.1:51771 | XXXXXXXX | Sleep | 148 | | NULL |
| 58 | application | 192.168.44.1:51968 | XXXXXXXX | Sleep | 11 | | NULL |
| 59 | root | localhost | NULL | Query | 0 | NULL | show processlist |
+----+-------------+--------------------+----------+---------+------+-------+------------------+
You will see complete details of different connections. Now you can kill the sleeping connection as below:
mysql> kill 55;
Query OK, 0 rows affected (0.00 sec)
kill $queryID; is helpful but if there is only one query causing an issue;
Having a lot of MySQL sleeping processes can cause a huge spike in your CPU load or IO
Here is a simple one-line command (if behind the MySQL server is linux) which would kill all of the current sleeping MySQL processes:
for i in `mysql -e "show processlist" | awk '/Sleep/ {print $1}'` ; do mysql -e "KILL $i;"; done
This is only a temporary repair; I strongly advise identifying and addressing the problem's main cause.
For instance, you may set the wait timeout variable to the amount of time you want MySQL to hold open connections before shutting them.
But if the issue still persists and you have to investigate the DB queries that cause the problem there is another way. In screen session, you can use another while cycle to continuously kill the sleeping queries. (while there is an output of the mysql show processlit | grep -i sleep | awk id column and kill it.) If you are using MySQL replication between different hosts this will help them to catch up. So when using show slave status\G; Seconds_behind_master will be going to catch up.
Of course, you should investigate the root cause again.
I found that my mysql sever have many of connection who is sleep. i want to delete them all.
so how i can configure my mysql server than then delete or dispose the connection who is in sleep not currently in process.
are this possible to delete this thing in mysql tell me how i can do following
a connection allow only one time datareader open and destroy the connection [process] after giving resposnse of query.
If you want to do it manually you can do like this:
login to Mysql as admin:
mysql -uroot -ppassword;
And than run command:
mysql> show processlist;
You will get something like below :
+----+-------------+--------------------+----------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+--------------------+----------+---------+------+-------+------------------+
| 49 | application | 192.168.44.1:51718 | XXXXXXXX | Sleep | 183 | | NULL ||
| 55 | application | 192.168.44.1:51769 | XXXXXXXX | Sleep | 148 | | NULL |
| 56 | application | 192.168.44.1:51770 | XXXXXXXX | Sleep | 148 | | NULL |
| 57 | application | 192.168.44.1:51771 | XXXXXXXX | Sleep | 148 | | NULL |
| 58 | application | 192.168.44.1:51968 | XXXXXXXX | Sleep | 11 | | NULL |
| 59 | root | localhost | NULL | Query | 0 | NULL | show processlist |
+----+-------------+--------------------+----------+---------+------+-------+------------------+
You will see complete details of different connections. Now you can kill the sleeping connection as below:
mysql> kill 52;
Query OK, 0 rows affected (0.00 sec)
Why would you want to delete a sleeping thread? MySQL creates threads for connection requests, and when the client disconnects the thread is put back into the cache and waits for another connection.
This reduces a lot of overhead of creating threads 'on-demand', and it's nothing to worry about. A sleeping thread uses about 256k of memory.
you can find all working process execute the sql:
show process;
and you will find the sleep process, if you want terminate it, please remember the processid and excute this sql:
kill processid
but actually you can set a timeout variable in my.cnf:
wait_timeout=15
connect_timeout=10
interactive_timeout=100
for me with MySql server on windows,
I update the file (because cannot set variable with sql request due privileges):
D:\MySQL\mysql-5.6.48-winx64\my.ini
add the lines:
wait_timeout=61
interactive_timeout=61
restart service, and acknowledge new values with:
SHOW VARIABLES LIKE '%_timeout';
==> i do a connection tests and after 1 minutes all 10+ connections in sleep are disapeared!