Re: [HACKERS] Tom Lane's fixes in v6.4.3

>Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp> writes:
>>> From Tom Lane's horror story...
>>> I spent an hour tracing through startup of 6.4.x, and I now understand
>>> why the thing doesn't crash despite the horrible bugs in ShmemInitHash.
>>> Read on, if you have a strong stomach.
>
>> Are Tom Lane's fixes included in 6.4.3 beta? I think his findings are
>> so important.
>
>I have made a patch for 6.4.x which I intend to commit into the REL6_4
>tree, but it hasn't gotten as much testing as I would like. The patch
>is attached if you care to try it for a while first. (These changes
>are already in the development tree, BTW.)

Thanks. Your patches work fine with fresh REL6_4 sources I got this
morning. One thing I noticed: when the backend runs out the
semaphores, postmatser dies with following messages:

IpcSemaphoreCreate: semget failed (No space left on device) key=5432017, num=16, permission=600
NOTICE: Message from PostgreSQL backend:
The Postmaster has informed me that some other backend died abnormally and possibly corrupted shared memory.
I have rolled back the current transaction and am going to terminate your database system connection and exit.
Please reconnect to the database system and repeat your query.

Is this normal?

I thought postmatser tried to re-initialize the shared buffer and
resume to the normal operation in this case.

BTW, 6.4 tree does not have the max backend patch I posted. So even if
there are enough resources, the backend will crash if connections >
MaxBackends.
--
Tatsuo Ishii