FreeTDS Development Group

[Björn Lundin <b.f.lundin AT gmail.com>]

I've experienced firewalls cutting idle connections
After 1 hour. 
Every 20 minutes, i did a dummy query as a workaround. 
Worked nice. 
Test by writing a program that connects, sleeps 3595 secs, 
Queries db, sleeps 3605 seconds. If crash second time, you know the 
timeframe. 

--
Björn 
Skickat från min iPhone

23 feb 2012 kl. 07:54 skrev Michael Peppler <mpeppler AT peppler.org>:

> On Feb 22, 2012, at 11:32 PM, Michelle Dupuis wrote:
> 
>> I have a C program using freetds ver 0.91 (package on CentOS 5.7).  All 
>> seems to work well, but after some idle time (eg: 5 hours) the connection 
>> seems to drop because attempts to issue a query result in error 20003 
>> (disconnect).  Is freetds disconnecting or is the Sybase server 
>> disconnecting the session?
>> Is there any way to prevent this?
> 
> Normally, Sybase will not disconnect an idle session. However, there are 
> ways to enable this (e.g. checking on various MDA tables, and killing idle 
> connections), so you check with your DBA that this is not in place on the 
> database side.
> I'm not 100% up to date on the FreeTDS internals, but I don't think that it 
> has any idle disconnect logic (I know for a fact that Sybase OpenClient 
> does not).
> Another possibility is that there is a router or firewall between your 
> program and the Sybase server, and it does idle disconnect - this is 
> something that is fairly common - so maybe check with your network admins.
> 
> If I remember correctly I think that Sybase OpenClient has an option to 
> turn on a keep-alive probe - I don't know if FreeTDS has included anything 
> similar. Enabling this should at least fool the network layer into thinking 
> that there is activity and avoid any disconnects from routers/firewalls.
> 
> Michael
> --
> Michael Peppler
> Sybase on Linux FAQ: http://www.peppler.org/FAQ/linux.html
> 
> "A successful [software] tool is one that was used to do something 
> undreamed of by its author." -- S. C. Johnson    
> 
> 
> 
> 
> 
> 
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