[error] "Shutting down mod_pagespeed child" after binary upgrade

[GoogleCodeExporter]

What steps will reproduce the problem?
1. upgrade to 1.1.23.1-r2169 binary

What is the expected output?

No [error]'s in the Apache logs.

What do you see instead?

[Tue Nov 13 10:51:34 2012] [error] [mod_pagespeed 1.1.23.1-2169 @29929] 
Shutting down mod_pagespeed child
[Tue Nov 13 10:51:35 2012] [error] [mod_pagespeed 1.1.23.1-2169 @32135] 
Shutting down mod_pagespeed child
[Tue Nov 13 10:51:36 2012] [error] [mod_pagespeed 1.1.23.1-2169 @30753] 
Shutting down mod_pagespeed child
[Tue Nov 13 10:51:37 2012] [error] [mod_pagespeed 1.1.23.1-2169 @32114] 
Shutting down mod_pagespeed child
[Tue Nov 13 10:51:38 2012] [error] [mod_pagespeed 1.1.23.1-2169 @32389] 
Shutting down mod_pagespeed child

What version of the product are you using (please check X-Mod-Pagespeed header)?

- ModPagespeed 1.1.23.1-r2169
- Debian GNU/Linux 6.0.6
- Apache 2.2.16-6

Three (3) separate servers are logging the same errors, proportionate to 
load/traffic.

Creating a 'cache.flush' file results in [warn] level errors:

[Tue Nov 13 11:08:07 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @5177] Cache 
Flush 0
[Tue Nov 13 11:08:08 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @3209] Cache 
Flush 0
[Tue Nov 13 11:08:08 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @5841] Cache 
Flush 0
[Tue Nov 13 11:08:09 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @5087] Cache 
Flush 0
[Tue Nov 13 11:08:09 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @5801] Cache 
Flush 0
...
[Tue Nov 13 11:12:27 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @8107] Cache 
Flush 0
[Tue Nov 13 11:12:28 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @8110] Cache 
Flush 0
[Tue Nov 13 11:12:28 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @8111] Cache 
Flush 0
[Tue Nov 13 11:12:29 2012] [error] [mod_pagespeed 1.1.23.1-2169 @8112] Shutting 
down mod_pagespeed child
[Tue Nov 13 11:12:30 2012] [error] [mod_pagespeed 1.1.23.1-2169 @8113] Shutting 
down mod_pagespeed child
[Tue Nov 13 11:12:31 2012] [error] [mod_pagespeed 1.1.23.1-2169 @7746] Shutting 
down mod_pagespeed child
[Tue Nov 13 11:12:31 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @7725] Cache 
Flush 0
[Tue Nov 13 11:12:32 2012] [error] [mod_pagespeed 1.1.23.1-2169 @7425] Shutting 
down mod_pagespeed child
[Tue Nov 13 11:12:33 2012] [error] [mod_pagespeed 1.1.23.1-2169 @8109] Shutting 
down mod_pagespeed child
[Tue Nov 13 11:12:34 2012] [warn] [mod_pagespeed 1.1.23.1-2169 @8017] Cache 
Flush 0

Which MPM?

prefork

URL of broken page: N/A all appear to be working normally

Original issue reported on code.google.com by dun...@chirp.com.au on 13 Nov 2012 at 9:18