Re: FATAL: could not read statistics message

On 5/16/06, Sean Davis <sdavis2(at)mail(dot)nih(dot)gov> wrote:
> I am using postgresql 8.1.0 on an Xserver running MacOS 10.3.9. I am
> getting the following in the log every minute for the past couple of days.
> The database is otherwise running normally, as far as I can tell:
>
> 2006-05-16 07:26:01 EDT FATAL: could not read statistics message:
> Resource temporarily unavailable
> 2006-05-16 07:27:01 EDT FATAL: could not read statistics message:
> Resource temporarily unavailable
> 2006-05-16 07:28:03 EDT FATAL: could not read statistics message:
> Resource temporarily unavailable
>
> I saw a previous message in the archives, but it did not appear that any
> conclusion was reached. Tom suggested that an EAGAIN signal was being
> received from the system, but I'm not sure what this means exactly or why it
> is happening now, as we have had the server running for months.
>
> Any insight?

I ran into this problem also on OS X running Postgresql 8.0. When you
start postgresql you usually see these 4 processes:

/usr/local/pgsql/bin/postmaster
postgres: writer process
postgres: stats buffer process
postgres: stats collector process

When I saw the same error as you, the stats collector process was
missing. A few times we also got messages like

[KERNEL]: no space in available paging segments; swapon suggested

and then a bunch of these:

postgres[13562]: [1-1] FATAL: could not read statistics message:
Resource temporarily unavailable

We thought it was our memory tuning of OS X. Since it wasn't a
production box, we didn't pursue the problem further. What tuning have
you done to postgresql.conf and the OS X memory settings?