Slow DB / outstanding requests

[Johan Meiring]

Hi,

Seeing as the list is quiet, something that might be of interest.

I am running 2.1.12 on a production server.
The server is (was) severly underpowered and the database was straining.

I was expenting the normal - "rejecting duplicate request".  (Cant remember exact error).

Then the server received about 30 access requests in about .1 second

It then went into a state where the following appeared over and over in the log:

Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 647 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 648 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 649 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 650 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 651 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 652 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 690 in component <core> module <queue>.
Mon Sep 12 11:33:46 2011 : Info: WARNING: Child is hung for request 685 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 691 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 692 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 693 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 694 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 677 in component <core> module <queue>.
Mon Sep 12 11:33:47 2011 : Info: WARNING: Child is hung for request 686 in component <core> module <queue>.
Mon Sep 12 11:33:48 2011 : Info: WARNING: Child is hung for request 625 in component <core> module <queue>.
Mon Sep 12 11:33:48 2011 : Info: WARNING: Child is hung for request 626 in component <core> module <queue>.
Mon Sep 12 11:33:48 2011 : Info: WARNING: Child is hung for request 627 in component <core> module <queue>.
Mon Sep 12 11:33:48 2011 : Info: WARNING: Child is hung for request 628 in component <core> module <queue>.


It never recovered.
Had to be restarted.
Even with no database queries outstanding.

Dont know if 2.1.12 has more "difficulty" with slow databases?

Unfortunately dont have more info, so this can probably be ignored.

Cheers,


-- 


Johan Meiring
Cape PC Services CC
Tel: (021) 883-8271
Fax: (021) 886-7782

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