UNIX for Advanced & Expert Users

Hello,

I am using Redhat redhat 4 update 4 kernal 2.6. My server is some time suddenly running slow.
The averge cpu load goes up to 50 to 60. (There is only two CPU and usually, the averge load
is between 1 to 2.5) That time, i see, there are several sessions connected.
Normally, we have 150 to 160 session. But when the server is slow, the total number of sessions
goes up to 400. At that time, it is taking long time to connect into the database. Even,
connecting into linux box is taking long time.

Our application server is showing this error message in log file.

ERROR] [2008-10-02 13:09:31] [JDBCExceptionReporter] The data source returned null from getConnection(user,password).
org.hibernate.exception.GenericJDBCException: Cannot open connection

Any one is phasing this problem??? Any direction to pursue this issue?

hi,

i think netstat -an would be a nice and simple method to see whether the server has reach its maximum port caused by application forking.

and for the serious part - a NIDS or NIPS should be placed in front of all servers network.

HTH.

hi ,

1. Please check with updates
2. Check with log file
3. JDBC connection is a problem better reonfig to JDBC connection
4. restart the JDBC service

kumar

Looks like connection error to me. What database are you connecting to? And is it local or remote? Check the max number of the allowed connections on the database listener you might be exceeding it under high load.

What database are you using? What is the max number of database connection you set in the server?

Hi All


Please give server model then can I give the best commands for u. other way’s I can’t do

Why update one kernel 2.6 before working fine right.