Re: [firebird-support] gds_thread_enter contention

> On Tuesday 06 May 2008, Dmitry Yemanov wrote:
>
> <originally posted on the support forums>
>
>> Bud Millwood wrote:
>> > - Does the fbclient library acquire a process-wide lock when a thread
>> > passes through it (even when connecting to fb-classic)? If so, doesn't
>> > that counteract the gains we get by running multiple fb-classic
>> > instances?
>>
>> Yes, fbclient is synchronized using some kind of global mutex. It is
>> acquired when any thread enters the API call and released as soon as the
>> network packet is ready to be sent to the remote server. So, the
>> blocking time is very short (compared to the network transport overhead
>> and the server side processing of the call) and I don't think it really
>> limits your performance.
>
> Hi Dmitry:
>
> I grabbed a developer here this morning and went back over our logic and our
> numbers, and we are both now reasonably sure that this lock *is* the source
> of the high contention. And from what we can tell, this lock is causing
> Firebird to fail to scale to its full potential.