Scoreboard is full,not at MaxRequestWorkers

问题

I an using Apache and Tomcat with mod-jk in my project. My web application is in Tomcat instances. I am using Apache jmeter for testing http load on tomcat. But I'm getting the error Scoreboard is full,not at MaxRequestWorkers even with 1000 threads.

[mpm_event:error] [pid 24313:tid 3075319488] AH00485: scoreboard is full, not at MaxRequestWorkers

[mpm_event:error] [pid 24313:tid 3075319488] AH00484: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting

I've configured http-mpm for approximately 5000 threads.

httd-mpm.conf file is:

<IfModule mpm_event_module>
    ServerLimit              200
    StartServers             3
    MinSpareThreads          75
    MaxSpareThreads          250
    MaxClients               5000 
    ThreadsPerChild          25
    MaxRequestWorkers        5000
    MaxConnectionsPerChild   5000
</IfModule>

Can anybody please guide me what can be the problem in this configuration?

回答1:

It seems that Apache tries to gracefully finish some of the processes and hangs while doing so. It might be a problem of Apache (https://bz.apache.org/bugzilla/show_bug.cgi?id=53555) or a problem of the application itself.

You can easily check it by looking at the server-status page of apache. In order to do that you need to enable the status.conf apache module. Then go to your-server.org/server-status. You will see all the processes and threads currently being used or gracefully finishing ("G"-state). If you have to many G's that don't go away, you found your problem. It would look sth like this:

Too many threads gracefully finishing...

The solution is pretty simple. Just set MaxConnectionsPerChild to 0 or comment it out (mpm_event.conf). What this does is just let the process continue it's work without restarting it. That's a good thing in our case, since restarting the process let to the problem of having to many G's filling up the scoreboard and eventually crashing Apache.

Hope that helped.

回答2:

I had this same problem. I tried different Apache versions and MPMs.

I seem to get this alot with MPM Worker. Also error does not reoccur using Apache 2.2.2

Are you using cPanel? IF so try /upcp --force and increase StartServers to a higher amount like 50 as that's all I did to get this error away.

回答3:

This serverfault Q&A suggests that the event mpm may have a bug. The recommended settings for at least partial workaround:

StartServers 3
MinSpareServers 5
MaxSpareServers 10
ServerLimit 250
MaxRequestWorkers 250
MaxConnectionsPerChild 1000
KeepAlive Off

回答4:

Try EnableMMAP Off in 00_default_settings.conf

来源：https://stackoverflow.com/questions/22576807/scoreboard-is-full-not-at-maxrequestworkers

标签

apache

Tomcat

httpd.conf

mod-jk