RE: Too many logs are written on Windows (LOG: could not reserveshared memory region (addr=%p) for child %p:)

Hi Noah, Magnus and Tsunakawa-san,


Thank you for replying.


> Can you adopt pgbouncer, to reduce
> the frequency of starting new backend processes?  That should improve your
> performance, too.

Actually, before I found that F-secure causes this message,
I recommend my customer to use connection pooling to reduce the number of connection times.


> Could you collect the information
> http://postgr.es/m/20181203053506.GB2860387@rfd.leadboat.com requests?
> That may help us understand your system's unusual behavior.  (The issue in that
> thread is related but not identical.)

Sorry. Since my customer uses PostgreSQL in production environment,
I cannot deploy debug modules.


> In this particular case, it seems it *was* helpful, no? That's how you found
> out the customer used a broken antivirus product, which may certainly also
> cause *other* issues.
> 
> Some sort of rate limiting to reduce the volume might help, but the message
> itself seems to have clearly been useful.

Yes. You are right.
The message itself was useful.
Your idea to reduce the volume seems good.


> We can change pgwin32_ReserveSharedMemoryRegion() to take an argument "int
> loglevel".  Then the caller first calls it with LOG, and DEBUGx afterwards.
> It may also be helpful for the caller to output "LOG:  tried %d times to
> reserve shared memory region" when the caller ran the function twice or
> more before success.  That explains the possibly long time or CPU spikes
> of connection establishment.

It seems good idea for me.


Regards,
Ryohei Takahashi