I have created JDBC Test Plan and i am using mysql database, with 'max number of connections:2' in 'connection pool configuration' but when i change it to 10 average response time increases.
My Question is 'max number of connections:2'in 'connection pool configuration' is referring to number of users?
I do not have ide about database performance testing, how database performance testing plan should be? i am assuming that increase number of users in thread group and report the response time. Can some one guid me with the sample database test plan as i do not know what component should be modified when testing for the performance.
Number of connections != number of users.
This "Max Number of Connections" is applicable for JDBC Connection Pool. JDBC Connections are very "expensive" to create hence normal practice is creating a pool so the connections can be established and used/reused by threads(users).
Ideally you should configure JDBC parameters to match your application settings, if you figure out that database responds slower due to the lack of available connections - you can test new configuration and suggest DBAs to change settings.
Number of users you should be setting on Thread Group level.
See The Real Secret to Building a Database Test Plan With JMeter article to learn more about concepts of database load testing using JMeter