RE: FW: query pg_stat_ssl hang 100%cpu

   Yes, checked the server history logs, we found when the backend starting hang there, operating system has out of memory that may lead to the allocation of RecordIdentierArray failed.   

Thanks,

James

-----Original Message-----
From: Thomas Munro <thomas.munro@gmail.com> 
Sent: Thursday, September 7, 2023 6:01 PM
To: James Pang (chaolpan) <chaolpan@cisco.com>
Cc: Michael Paquier <michael@paquier.xyz>; PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: FW: query pg_stat_ssl hang 100%cpu

On Thu, Sep 7, 2023 at 9:38 PM James Pang (chaolpan) <chaolpan@cisco.com> wrote:
> (gdb) p  RecordCacheArrayLen
> $3 = 0

Clearly this system lacks check against wrapping around, but it must be hard work to allocate billions of typmods...

Or maybe if in an earlier call we assigned RecordCacheArray but the allocation of RecordIdentifierArray failed (a clue would be that it is still NULL), we never manage to assign RecordCacheArrayLen a non-zero value?  But it must be unlikely for a small allocation to fail...