Sorry to bring back this old user thread on dev ML, but I think we should defintively made this configurable. At least to allow
people to easily
try 2 basic configurations (ie -1 or 600000) and especially to make people aware of possible problems there.
The related doc is here
http://commons.apache.org/dbcp/configuration.html.
Jacques
From: "David E Jones" <
[hidden email]>
To: <
[hidden email]>
Sent: Thursday, January 31, 2008 8:10 PM
Subject: Re: Stale DB-connections
>
> This is an interesting find Hans.
>
> Has anyone noticed, or tested, this with other databases (ie other than MySQL which is what Hans mentions testing with)?
>
> The big question in my mind is do we turn it off altogether, or make it a configurable option with recommended settings for
> different databases?
>
> If anyone can take a peek at their system(s) and offer feedback that would be great.
>
> -David
>
>
> On Jan 31, 2008, at 12:37 AM, Hans Holmlund wrote:
>
>> I have just upgraded to the latest version of Entity Engine and stumbled upon a problem. The problem I had was that
>> db-connections were dropped after awhile but without actually closing the TCP session with the database. So when I checked with
>> netstat I had a lot of connections in a CLOSE_WAIT state. I'm using MySQL but I guess this may happen with other databases too.
>> I had a look in the code and come up with a fix. In DBCPConnectionFactory (row 96) there is a line saying:
>> pool.setTimeBetweenEvictionRunsMillis(600000);
>>
>> In GenericPool to set this parameter has the effect of creating an eviction thread, so every 10 minutes the pool will be checked
>> if there exist any unused objects. The problem seems to be when the object is evicted, I'm not sure what is happening but the
>> object is not correctly removed.
>> I don't think that this cleaning procedure is necessary, if I have set the pool-maxsize to 200 I can probably live with that the
>> actual pool-size never shrinks.
>> So I made this change:
>> pool.setTimeBetweenEvictionRunsMillis(-1);
>> The eviction thread will not be created. And after I made this change I have not had any problems with stale DB-connections.
>>
>> / Hans Holmlund
>
>
Locked
