tcp_conn_request_max

[fiorenzo monteleone]

I have application with upper 500 simultaneous connections.
I have "connect requests dropped due to full queue" in the netstat -p tcp.
I increase the parameter "tcp_conn_request_max" from 4096 to 16384 but I have the same error in the netstat.
I also increased parameter "tcp_syn_rcvd_max" from 500 to 5000 but I have the same error.
Any suggestions?
Thanks.

[Ludovic Derlyn]

hi,

see
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=207158

regards

L-DERLYN

[rick jones]

The number of pending connections which can be queued to a listen() endpoint is the minimum of tcp_conn_request_max and whatever the application passes in a call to listen().

So, I suspect you need to get your application to start making a call to listen() with a larger backlog.

I _seriously_ doubt you need a queue of 16384 entries - heck, 4096 seems high to me. I'd try 1024 for both tcp_conn_request_max and your listen() call and then go from there.

[fiorenzo monteleone]

I tested all the possible value for parameter "tcp_conn_request_max" but I have the same problem of "connect requests dropped due to full queue" when I open around 225 connections simultaneous.
The request of connection are http and the application server is Bea Weblogic.
At this moment I suspect that the problem can be a weblogic parameter but I don't know weblogic parameter that is correlate with this kind of problem.

[Chan 007]

Hi,

Please find the link for the weblogic parameters...

Increasing "tcp_conn_request_max" will not help you.

Check your application code.

Chan

[fiorenzo monteleone]

What do you thing about the patch PHNE_23068 that increase the listen backlog requested by inetd from 128 to 1024?

[rick jones]

Increasing inetd's listen backlog would only help for those services launched via inetd. I suspect that the BEA weblogic web server is not launched that way, which means you have to go and find the parameter for weblogic to have it set its listen() backlog. No way around it.

[fiorenzo monteleone]

I changed the parameter "Accept Backlog" from 50 to 500 in config.xml of weblogic and I haven't the error of "connect requests dropped due to full queue" in tcp stack.
The problem seems resolved thanks everyone for collaboration.
Bye Fiorenzo.