[Opensource] Expresso connection issues

[netwisercn]

Hi, everyone,  one of my friend run into these situation, I forward it
to you and try to find something helpful, any input is highly
appreciated.

 

I have the following problem:

 

1. After running a period of time, my java program suddenly generated
150-300s of connections in one minute. 

2. To response the query made by JavaBeans. 

3. After the connections are generated(say 320 connections), almost all
the connections are being used, though I set the DB time-out variable to
be very short(several minutes). 

4. There will be around 300 query to DB per second with high web load. 

5. The requests from clients will be delayed or not responded by the web
server during the connections generating period since there is a high
CPU/Mem load with the server, and then the web server generated many
HTTPD thread up to its max clients value and refuse all the users to be
connected. 

6. If I reload the Appserver or DB Server, there will be only 40-50
connections generated while the server working  fine, but several hours
or one day later, the problem occur again. 

7. The swap used may accumulated from several MB up to about 1GB.

 

Versions: MySQL 4.0.13, Red Hat 7.1, Resin 2.1.9 Apache 1.3.27
DBConnectionPool: Expresso 

 

 

30722  7:11:34  Aborted connection 43785 to db: 'DB' user: 'user' host:
`localhost' (Got timeout reading communication packets)

 

Does anybody meet such a problem? I want to know what may cause so many
DB connection, and how to avoid the server going down.

 

Any suggestions welcome.

 

 

James 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.jcorporate.com/pipermail/opensource/attachments/20030725/9f342248/attachment-0002.htm