Reason for asking this is that, I have been firing around 200 concurrent connections via SOAP to a web service, and in MySQL, I have never seen more than 20 connections being processed at a time.

My MySQL settings are as below: max_connections=1000 max_user_connections=50

MySQL show variables have confirmed that these are the settings in effect, so I am tempted to rule out MySQL.

Any inputs from anyone familiar with JBOSS (EJB) or Tomcat could shed some light on this?


This is most likely a limit on the data source config on the JDBC MySQL driver then in your setup - wherever you have your data source defined look for the max connections property. Depending on your setup this could be in several locations defined differently (i.e. in server.xml at the Tomcat level vs. in web.xml at the webapp/ level), but it's in there somewhere. Maybe try a grep for "20" w/ quotes or >20< (nested in XML) first...

  • Your pointer definitely helped, but it wasn't server.xml or web.xml. The main culprit here is mysql-ds.xml and missing <min-pool-size> and <max-pool-size> configurations. Once I added them in, extra connections come in instantly :D – blacklotus Jun 29 '10 at 2:34
  • cool cool, your config was specifically JBoss then (my examples were Tomcat). you got the idea, glad to see it's fixed. :) – troyengel Jun 29 '10 at 3:23

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