[rsyslog] Three bugs to stable v2 reported to Red Hat

[Tomas Heinrich]

On 08/31/2009 10:00 PM, Rainer Gerhards wrote:
>> The limitation of 1000 open file descriptors however (limitation of 
>> select()) is still there in newer rsyslog releases and 
>> therefor we are 
>> probably forced to work around it. Although I find it 
>> personally strange 
>> that this limitation is not a more widespread problem. Is 
>> everybody using 
>> a database backend ? Or are people segregating syslog messages by 
>> location/importance ?
> 
> I am not sure tha it is a select() limit. I routinely run tests with 2000 tcp
> connections under Fedora and it works well. An issue, of course, is the
> per-process file handle limit, which (on many systems) is 1,024. In current
> releases, you can simple increase that limit via the $MaxOpenFiles directive:

Part of the problem, based on the log excerpt from one of the bug 
reports, is that the file descriptor limit for the process is too low;

   Aug  1 19:10:30 lg2log01 rsyslogd:tcp accept, ignoring error and
   connection request: Too many open files
   Aug  1 19:10:34 lg2log01 rsyslogd:last message repeated 49 times
   Aug  1 19:10:33 lg2log01 rsyslogd:tcp accept, ignoring error and
   connection request: Too many open files

This isn't caused by select(). It should be possible to change the limit 
with 'ulimit -n <nbr>'.

The issue with select() remains, though. It has a hardcoded limit on the 
number of file descriptors of FD_SETSIZE. I've run a test with rsyslog 
2.0.6 and I haven't been able to receive messages from tcp clients with 
fds > 1024.

Tomas