Title: Database connection error with high concurrent users
Last modified: August 24, 2016

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# Database connection error with high concurrent users

 *  [mortimer](https://wordpress.org/support/users/mortimer/)
 * (@mortimer)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/)
 * I’m having database connection errors with 100+ concurrent users. Hosted on a
   dedicated host with quad core and 16GB RAM.
 * I’m currently monitoring with New Relic and here are screenshots: [https://onedrive.live.com/redir?page=view&resid=D17715711192A7B8!148&authkey=!AKY5oKbTRy8JC80](https://onedrive.live.com/redir?page=view&resid=D17715711192A7B8!148&authkey=!AKY5oKbTRy8JC80)
 * What would be the best method to start troubleshooting this?
 * What I’ve done so far:
    WP Database repair Tested without plugins (did a little
   better on current users but still very slow or crashed) Simulated load with loader.
   io (crashing around 100-200 concurrent users, seeing similar real world issues)

Viewing 6 replies - 1 through 6 (of 6 total)

 *  Thread Starter [mortimer](https://wordpress.org/support/users/mortimer/)
 * (@mortimer)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170620)
 * A little extra info – this site has a few thousand posts. Also, the test I did
   without plugins was with the plugins disabled. I’ll run a test on a bare install
   of WP in the morning to see how that does.
 *  [accuwebhosting](https://wordpress.org/support/users/accuwebhosting/)
 * (@accuwebhosting)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170627)
 * Hi,
 * You will need to tweak MySQL server settings so that it can accommodate more 
   concurrent users. MySQL connection rates can be improved by either adjusting 
   MySQL settings, or providing more memory and processing power to the overworked
   server. Query caching and proper indexing can also help to improve MySQL performance.
   Refer following guides to tweak MySQL server for big number of concurrent connections.
 * [http://dev.mysql.com/doc/refman/5.1/en/too-many-connections.html](http://dev.mysql.com/doc/refman/5.1/en/too-many-connections.html)
 * [https://www.percona.com/blog/2014/01/28/10-mysql-settings-to-tune-after-installation/](https://www.percona.com/blog/2014/01/28/10-mysql-settings-to-tune-after-installation/)
 * [https://codex.wordpress.org/High_Traffic_Tips_For_WordPress](https://codex.wordpress.org/High_Traffic_Tips_For_WordPress)
 * Thanks,
 *  Thread Starter [mortimer](https://wordpress.org/support/users/mortimer/)
 * (@mortimer)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170716)
 * I used the Percona tool for my.cnf config but the performance doesn’t appear 
   to be improved. I was able to crash the server with a load test on a fresh install
   of WP so that at least reasonably rules out an issue with the install.
 * Mysql is still maxed at 200mb of memory usage, shouldn’t that be changing? The
   database size is around 100mb.
 * This is what I used in the config file: [http://pastebin.com/h0Q2TCTG](http://pastebin.com/h0Q2TCTG)
 *  [Lalit Nagrath](https://wordpress.org/support/users/laliz/)
 * (@laliz)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170719)
 * > Mysql is still maxed at 200mb of memory usage
 * you can try bumping it to 2gb or something and then test it. also i wasnt able
   to acess New relic Screenshots
 *  Thread Starter [mortimer](https://wordpress.org/support/users/mortimer/)
 * (@mortimer)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170722)
 * Sorry, there was a blank page in the notebook. View with this [link](https://onedrive.live.com/view.aspx?resid=D17715711192A7B8!148&app=OneNote&authkey=!AKY5oKbTRy8JC80).
 * How would I bump up the memory to 2gb? The generated config file from the Percona
   tool should have increased it past 200mb but it appears to have not.
 *  [Lalit Nagrath](https://wordpress.org/support/users/laliz/)
 * (@laliz)
 * [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170723)
 * this article has some good points beside links posted by accuwebshotsing above
 * [http://www.ewhathow.com/2013/09/how-to-increase-mysql-memory-limit/](http://www.ewhathow.com/2013/09/how-to-increase-mysql-memory-limit/)
   experiemnt with them and select the one’s which works best for your website
 * also your relic screenshot doesnt display much load. CPU was 50% at 100 concurrent
   users and RAM wasnt’used much either.

Viewing 6 replies - 1 through 6 (of 6 total)

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## Tags

 * [connection](https://wordpress.org/support/topic-tag/connection/)
 * [database](https://wordpress.org/support/topic-tag/database/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 6 replies
 * 3 participants
 * Last reply from: [Lalit Nagrath](https://wordpress.org/support/users/laliz/)
 * Last activity: [10 years, 11 months ago](https://wordpress.org/support/topic/database-connection-error-with-high-concurrent-users/#post-6170723)
 * Status: not resolved

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