CA Access Gateway (SPS) AH00288: scoreboard is full, not at MaxRequestWorkers
Article ID: 130088
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We're running a CA Access Gateway (SPS) and this one reports the error :
[Fri Mar 01 09:53:55.553673 2019] [mpm_worker:error] [pid 8594:tid 4152100608] AH00288: scoreboard is full, not at MaxRequestWorkers
and we'd like to know how to fix it ?
The error "AH00485: scoreboard is full, not at MaxRequestWorkers" is known issue and if we read the bug's comments, the symptoms are very similar to what we experience in your environment. More, we're investigating the mpm server parameters as we can see in the bug's comments too. From the bug's comments, we see that there's no work around or specific configuration to solve this error line and performance issues when this appear.
So we have big chances to solve this issue by applying the 12.52SP1CR09 to the CA Access Gateway (SPS) and run Apache higher level of 2.4.25.
Let's highlight some comments here :
Scoreboard full error with event/ssl
A high-traffic web server using event MPM and mostly receiving HTTPS requests frequently got the error "scoreboard is full, not at MaxRequestWorkers" and showed very bad performance.
We fixed the issue by reverting from 2.4.2 to 2.2.22, still using event MPM.
We've seen AH00485: scoreboard is full, not at MaxRequestWorkers on 2.4.4 with the event MPM, no SSL involved.
Apache 2.4.10 on Slackware Linux 14.1 x86_64 platform.
I am seeing this about once a minute in the logs: AH00485: scoreboard is full, not at MaxRequestWorkers
I was able to recover only by a forced restart (stop then start).
I was able to manage this issue by reducing GracefulShutdownTimeout value and increasing MaxClients / MaxRequestWorkers value to make more room for Apache scoreboard .
Also I reduce no of MaxKeepAliveRequests Apache global level.
For more info :- https://www.tectut.com/2016/04/workaround-for-scoreboard-is-full-not-at-maxrequestworkers
We have successfully used patch in #55 for 50 days now on mid-sized production server with 1-2 million hits per day. No issues encountered. Previous issues disappeared (we think the original bug had been abused in DoS attack, but we might be wrong on this).
Use all scoreboard entries up to ServerLimit, for 2.4
This looks good. Should be proposed for back port!!
Fixed in 2.4.25
In the meantime I've decreased the ServerLimit/ThreadLimit to 5 and increased the ServerLimit 160 and more. The results with these settings are very good, no more user complaints (see below).
Otherwise those long running HTTP CONNECT sessions were still maxing out the total number of allowed processes.
> If you have any more experiences with the patch I am certainly > interested. Even if it has simply run for some time without (new) > bugs exposed.
the patch had been deployed to about ~3.000 servers since November 2016 with different work loads from 10 users to 400+ users. After applying your patch + the ThreadLimit change, there were no more complaints :)
I've also diffed httpd 2.4.23 + the patch with the version of the code that landed in 2.4.25 and it's exactly the same. I'm soon going to roll out 2.4.25 to those boxes.