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From Daniel <dferra...@gmail.com>
Subject Re: [users@httpd] Apache 2.4.10 AH00485: scoreboard is full, not at MaxRequestWorkers
Date Fri, 30 Jan 2015 02:34:34 GMT
2015-01-30 1:03 GMT+01:00 Mark Jacquet <mark_jacquet@yahoo.com.invalid>:

> Problem: Apache server will stay up for random amount of time, usually
> days, but eventually enters a hung state. When hung the CPU load gradually
> spikes on the machine
>  and new web server requests are unresponsive.
>
> Error logs typically contain lots of these:
>
>     Wed Jan 28 16:06:58.667188 2015] [mpm_event:error] [pid 25336:tid 1]
> AH00485: scoreboard is full, not at MaxRequestWorkers
> I have done a lot of web research on this top and have found many cases
> where others o=have had the same/similar issue but no real solutions. Seem
> very close to this bug report:
> https://issues.apache.org/bugzilla/show_bug.cgi?id=53555
>
> Environment:
>
> LDOM (VM) SunOS myhostname 5.10 Generic_118833-36 sun4v sparc
> SUNW,Sun-Fire-T200
> 8G RAM
>
> http Conf:
>
> StartServers                8
> MinSpareServers             Not set
> MaxSpareServers             Not set
> ServerLimit                 256
> MaxRequestWorkers           100
> MaxConnectionsPerChild      1000
> KeepAlive                   On
> TimeOut                     3000
> MaxKeepAliveRequests        50
> KeepAliveTimeout            2
>
> Current non-hung Score Board:
>
> Server Version: Apache/2.4.10 (Unix)
> Server MPM: event
> Server Built: Oct 30 2014 16:29:03
>
> Current Time: Wednesday, 28-Jan-2015 10:59:39 PST
> Restart Time: Wednesday, 28-Jan-2015 09:49:21 PST
> Parent Server Config. Generation: 1
> Parent Server MPM Generation: 0
> Server uptime: 1 hour 10 minutes 17 seconds
> Server load: 0.60 0.46 0.41
> Total accesses: 1134 - Total Traffic: 2.2 GB
> CPU Usage: u9.07 s16.94 cu609.51 cs69.31 - 16.7% CPU load
> .269 requests/sec - 0.5 MB/second - 2.0 MB/request
> 1 requests currently being processed, 99 idle workers
>
> PID Connections     Threads Async connections
> total   accepting   busy    idle    writing keep-alive  closing
> 25337   0   yes 1   24  0   0   0
> 25338   1   yes 0   25  1   0   0
> 25339   1   yes 0   25  0   0   1
> 25340   1   yes 0   25  0   0   1
> Sum 3       1   99  1   0   2
>
> Any thoughts/comments on http conf tuning, OS patches, apache bug fixes
> appreciated.
>
> This is a production server, so you can imagine, having it go down at
> random times (usually when I am asleep) is not fun!
>
> Thanks.
> MJ
>
>
>

Hello,

you have some odd values.

First you don't specify ThreadsPerChild, which by default is 64. Yet you do
specify the maxrequestworkers which represents the total of threads in all
child processes together, but you specify a maximun of 256 processes.

By a simple math, 256 process * 64 childs per process would yield 16384
threads in total, yet you are just allowing a maximun of 100, so
effectively your server is just capable of starting 1 single process and
thus, every time you restart, having no "spare" processes available you
will get scoreboard is full message.

Consider something more logical like this for starters:

StartServers            1 <-- starts with 1 process
ServerLimit             5 <-- 4 more process available, 5 x 200 max threads
= 1000 (as you can see bellow, math matches maxrequestworkers)
MinSpareThreads         25
MaxSpareThreads         100
ThreadsPerChild         200 <-- threads per child process
ThreadLimit             200 <---max threads per child process
MaxRequestWorkers       1000 <--- a total of 1000 threads
MaxConnectionsPerChild  10000000

This is an example, adjust to your needs.



-- 
*Daniel Ferradal*
IT Specialist

email         dferradal@gmail.com
linkedin     es.linkedin.com/in/danielferradal

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