Help:: Listen queue overflow killing servers

John Johnstone jjohnstone.nospamfreebsd at
Fri Jul 26 15:10:04 UTC 2019

On 7/26/19 9:24 AM, MJ wrote:
> On 26/07/2019 11:08 pm, Paul Macdonald via freebsd-questions wrote:
>> On 26/07/2019 13:52, Robert Schulze wrote:

>> One of the things we do (whihc may be bad)  is to log to a single file 
>> ( e.g all.sites.log, this doesn;t seem to cause problems in general , 
>> but i can see how if there's X child processes then they may all need 
>> write locks)
> Unless it's hammering the log and there's locks on it.
>> Is that a really bad idea? ( Often handy to have one file for 
>> differnet vhosts, but maybe that needs a rethink)
> Syslog works this way.

With syslog there are multiple processes all their messages to port 514. 
  There is just a single process syslogd which then writes to its files.

The situation here seems to be that all.sites.log is opened for writing 
with shared access by multiple processes which would be different from 
syslog.  Maybe that approach should also be taken here.

With any approach, with one log file there is a serialization of 
everything written to that file.  The throughput of the method that does 
that becomes a limiting factor.  Maybe that limit is being reached.

John J.

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