Changing KeepAlive to Off does not help, the issue occurs at this point where obviously due to MaxConnectionsPerChild a Process should become killed.
As observed, the problem is that (in the example stated) both PIDs 11454 and 16555 do not become killed because of these remaining connections, which is ok, since these could be remaining downloads or something to a client. But then, Apache does neither fork new processes to accept new connections nor does it kill the both PIDs (which is as just statet, ok) - the scoreboard is full then in that case and new connections can not be accepted. As I see a solution to this problem is that the main httpd process should be 1. able to fork new processes 2. I see no reason why the scoreboard is full then, 1+2 connections is 3, not 2x64=128, in that given case 125 free slots are wasted since they are blocked by the 2 remaining processes which show connections which fill up the scoreboard, those are shown as "G"s in the scoreboard for both PIDs - that should not be the case. Since 2.4.2 (the first I've used) I did not understand why a finishing/killing process shows all "G"s - however, that issue did not occur in 2.2 when I used MPM event in experimental stage, but in 2.2 I did not have that problem, the connections were counted as usual. Probably because lots of the code was taken from MPM worker, where the calculations were still correct, until fully adopted to 2.4. By this theory, also MPM worker might experience this, however, due to the different design MPM worker also may never get to that point to show this behavior and error messages in the log. So my conclusion is also a question: why are finishing processes showing all "G"s in the scoreboard, and/or why are these finishing threads all counted in the scoreboard (here: 2x64 instead of 1+2, causing 125 threads to be wasted). I would expect this issue to become much more important when most people upgrade to 2.4, also I clearly would say this is a bug.
On Thu, Sep 6, 2012 at 11:21 PM, Sam <[email protected] <mailto:[email protected]>> wrote:Never, the server is not even under high load. There are several thousand vhosts, it is about shared webhosting. This is what server-status says: PID Connections Threads Async connections total accepting busy idle writing keep-alive closing 21388 257 yes 44 20 0 171 44 11454 2 no 0 0 0 0 0 16555 1 no 0 0 0 0 0 Sum 260 44 20 0 171 44How about those 171 in keep-alive? What are your KeepAlive and KeepAliveTimeout settings? Maybe try switching KeepAlive off? Whit only 192 threads and KeepAlive On you are imposing DoS on your self in case of long timeout.That one PID 11454has "2" connections, 16555 has "1", all other values are 0, I guess it should become killed? - but it does not, it stays like this for a while (I don't know on what this "while" depends on). At this point all 3 rows are filled with stuff, such as: WWW_W_WWWWWW_WW_W_W_W_WW__WWW__WW__WWWWWW__WWW__W__W_RWWWWRWWWWW GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG GGGGGGGGGGGGGGGLGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG But as you see, due to several _ this means that there are not all 192 busy, in fact: 105 requests/sec - 2.5 MB/second - 24.8 kB/request 44 requests currently being processed, 20 idle workers WHY can no others be used? With the statement above it means that 128 (which is 192-64) workers are unused because they should become killed already, to spawn new ones, these are the ones in the 2. and 3. row with "G"s. -- So the rest is occupied with "G". In Apache 2.2 I used MPM_event as well, this obviously never occured because the both PIDs above which are showing G only showed just dots in that case, now after one PID should be finished, all slots become occupied with G, which obviously causes a full scoreboard. I would consider this a bug, a serious one for my case, since it often occurs (~1-3 times per hour) that the server stops accepting new requests, just because of that full scoreboard, where the server is neither busy, nor do I see what configuration directive should be configured badly. Again: KeepAlive On ListenBacklog 4095 Timeout 20 KeepAliveTimeout 8 MaxKeepAliveRequests 16192 MaxRanges 200 MaxRangeOverlaps 20 MaxRangeReversals 20 GracefulShutdownTimeout 6 LimitInternalRecursion 10 LimitRequestFieldSize 4094 LimitRequestFields 40 LimitRequestLine 4094 LimitXMLRequestBody 786432 MaxRequestWorkers 192 ServerLimit 3 StartServers 2 MaxMemFree 2048 MinSpareThreads 64 MaxSpareThreads 64 ThreadLimit 128 ThreadsPerChild 64 MaxConnectionsPerChild 10240 AsyncRequestWorkerFactor 10 I assumed AsyncRequestWorkerFactor to have something to do with it, I raised it from 2 (default) to 10, no change. By the way: after some time (in this case above both) PIDs become killed finally, releasing 2x64 slots in the scoreboard, the waring messages vanish and the server can respond again well to requests. In the interest of finding a workaround until this is fixed: what configuration directives control that timeout or whatever, which cause these PIDs to become killed?On Thu, Sep 6, 2012 at 7:06 PM, Sam <[email protected] <mailto:[email protected]>> wrote: Yes, I still see such messages even after upgrading to 2.4.3On Sun, Aug 19, 2012 at 8:25 AM, Sam<[email protected]> <mailto:[email protected]> wrote:I upgraded to Apache 2.4 and use mod_event on a server having average high load. My issue is that I am getting pretty much often the error message within the error log AH00485: scoreboard is full, not at MaxRequestWorkers What causes this? The server almost stops to handle new requests when this occurs. MaxRequestWorkers 192 ServerLimit 3 StartServers 2 MaxMemFree 2048 MinSpareThreads 64 MaxSpareThreads 64 ThreadLimit 64 ThreadsPerChild 64 MaxConnectionsPerChild 10240 AsyncRequestWorkerFactor 2So you never have more than 192 simultaneous requests at any given time ???
