Re: Weird database hanging

Thanks to all those who responded. Some web applications do use connection pooling and some don't. I will need to find out the upper limits on the session pool size and also the rate of session starts. Thanks for the pointers.

Thanks,
Sunil.

On 9/18/07, Nigel Thomas <nigel_cl_thomas_at_yahoo.com> wrote:
>
> ----- Original Message ----
> From: Sunil Kanderi sunil.kanderi_at_gmail.com
>
>
> .... We have lots of web applications running from that database and once
> in a while there is a sudden spike in the number of connections from a
> Oracle user related to one of the web applications and the concurrent
> connections for that particular web application user jumps from 10 or 15
> concurrent connections to 100s in less than a couple of minutes. The
> database and the server hang until these connections are cleared. At times
> we cannot even get a connection to the server when this happens. I usually
> don't see any alerts in the alert log when this happens.
> ---------------
>
> Sunil
>
> From this, I can't say why you see the initial slowdown - but I can say it
> is common for connection pools to behave suicidally when faced with a slow
> down. Traffic piling into the connection pool causes an explosion in the
> number of connections - and there's nothing like a flood of new connections
> to make the traffic jam worse. See
> http://preferisco.blogspot.com/2007/02/avoiding-application-suicide-by-session.html
> .
>
> Regards Nigel
>

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