Re: Database server restarting

On Tue, 6 May 2003, shoaib wrote:

> Hello,
>
> Thanks for you kind help.
>
> But is there any particular reason for database to do such kind of
> behavior.
> DEBUG:  pq_recvbuf: unexpected EOF on client connection
> DEBUG:  pq_recvbuf: unexpected EOF on client connection
> DEBUG:  pq_recvbuf: unexpected EOF on client connection
> DEBUG:  pq_recvbuf: unexpected EOF on client connection
> DEBUG:  database system was interrupted at 2003-05-03 04:17:19 SGT
> DEBUG:  checkpoint record is at 3/85EA18B0
> DEBUG:  redo record is at 3/85EA18B0; undo record is at 0/0; shutdown
> FALSE
> DEBUG:  next transaction id: 4111285; next oid: 7557242
> DEBUG:  database system was not properly shut down; automatic recovery
> in progress
> DEBUG:  ReadRecord: record with zero length at 3/85EA18F0
> DEBUG:  redo is not required
> DEBUG:  recycled transaction log file 0000000300000083
> DEBUG:  recycled transaction log file 0000000300000084
> DEBUG:  database system is ready
> DEBUG:  pq_recvbuf: unexpected EOF on client connection
>
> Is there any particular reason for this thing.

Well, there are probably lots of potential causes but consider something like
this:

process A starts up
process A uses N MB of memory
process A loops
process A uses N+1 MB of memory
...
process B starts up and connects to DB
memory available is 1MB
process A loops
process A uses N+1 MB of memory
proi
process B wants 10KB more memory
process B dies for want of memory allocation checks
DB notes the unexpected EOF on the connection from B
process A loops
process A wants N+1 MB of memory
process A retries N+1 MB of memory
process A retries N+1 MB of memory
process A retries N+1 MB of memory
process A retries N+1 MB of memory
...
system can't start any other process for lack of memory resources


You've got high system load, inability for processes to claim more memory and
errors about programs exiting at unexpected times.


--
Nigel Andrews