Increasing connections on servers.

[conectividade]

Hi folks!!

Our CSS11501 was LB of 5 servers, port 443, but the number of established

conections was increasing until that service stoped.

That servers are: IBM X.series - Red Hat 7.3 - Apache and Websphere.

The same situation was happened with other 2 servers (dotnet), the number

of established connections was increasing, and the consumption of memory

too, until that server stoped. This service don´t use persistence.

That servers are: Sun-Intel-Zeon - Win 2003 server

Anybody already saw something like that?

But I can´t saw that connections fixed on CSS.

What we could make to correct this problem?

simple lay-out of our net is attached

[Gilles Dufour]

you can use the command 'maxconn' to limit the number of connections per server.

Connections in excess of maxconn will be dropped.

If the connections you are receiving are valid and constantly surpassing maxconn, I would recommend to increase the number of servers.

Regards,

Gilles.

[conectividade]

x

[conectividade]

Gilles, thanks!

But, it´s normal? Why this happen?

Another thing, if the connections are directed to server without CSS it doesn't happen. The service stay alive.

If I config max connections on service, when this connections will close?

Or exist any other thing to do on CSS?

flow-timeout-multiplier and flow-reset-reject could help or not?

What this comands does?

thanks a lot,

Renato

[Gilles Dufour]

Renato,

your initial explanation did not mention why the number of connections was increasing.

Maybe this is what you should investigate first.

Capture sniffer trace and identify what is going on.

If the connections is dropped by the CSS, a RESET is being sent, so the servers should also clean its connection - no performance issue there.

If you start playing with the flow-timeout-multiplier, connections will still open a longer time.

If your not sure what is causing the number of connections to increase, this command could have a bad effect as it will keep the connection alive even if not used.

In conclusion, try to identify the reason for the connections to increase.

Does it increase on the CSS [sho summary] ?

or just on the server ?

Regards,

Gilles.