system crashing

system crashing

by jalal alsgahyer -
Number of replies: 3

Hi,

we have small moodle site ( 300 users ) , this site every 3 to 4 days show some problems most of them "Json syntax errors " i should be restarted Apache server  every time to back the system working fine again,

Actually  no more 70 user login to the system at the same time or using any activity at the same time , but this errors still apeare 

"  specially in quiz activity "

like:

- PHP Warning:  Declaration of ArrayObject::ksort() should be compatible with ArrayObject::uasort($cmp_function) in  drive:C:\ \-\-\-\\-\\moodle\\cache\\lib.php on line 181.

-Declaration of ArrayObject:sad) should be compatible with ArrayObject:: in C:\\-\\- \\-\\-\\moodle\\cache\\lib.php on line 181.

-the specified network name is no longer available.  : AH00341: winnt_accept: Asynchronous AcceptEx failed.

-VirtualAlloc() failed: [0x00000008] Not enough storage is available to process this command.

VirtualFree() failed: [0x000001e7] Attempt to access invalid address.


our server : Windows server , Intel (R) Xeon cpu 2.53GHz , RAM 6 GB ,

PHP 7.1 , apache 2.4 , mysql 5.6

is the problem in hardware issue or what ?


Regards

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In reply to jalal alsgahyer

Re: system crashing

by Visvanath Ratnaweera -
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Hi

Whether a site is small depends on how big the server is. If we take a not-so-scientific rule of thumb circulating in this forum saying "10-20 concurrent users per GB of memory", your 6 GB should support 60 to 120 concurrent users. 70 logged-in users (not concurrent users) and the 30 (concurrent) quiz users as mentioned in https://moodle.org/mod/forum/discuss.php?d=412853 fall below expectations. So let us continue assuming that hardware could do better.

BTW, how many cores and threads does your Xeon CPU have?

The usual practice is to monitor the server during such heavy loads and dig deep to find bottleneck. But in your case, there are serious system errors (valloc, vfree). So the first step should be to raise the https://docs.moodle.org/en/Debugging level to find out in which part of the code the error happens. I am not able to give any detailed instructions since I don't use Windows. In fact most of the community here use some sort of Unix/Linux. Luckily there are a few helpers from the Windows Server world.

P.S. Could you kindly post a note in your previous discussion https://moodle.org/mod/forum/discuss.php?d=412853 that the continuation is here. Discussing the same thing in two threads more than double the work of the helpers.
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In reply to Visvanath Ratnaweera

Re: system crashing

by jalal alsgahyer -
thanks Mr. Ratnaweera
I will check the Debugging ,
about my previous discussion "https://moodle.org/mod/forum/discuss.php?d=412853 " ,when I discussed this case in other forum the helpers suggested to post the case in performance forum because this i repost here , so sorry for duplication

Regards,
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In reply to jalal alsgahyer

Re: system crashing

by Visvanath Ratnaweera -
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The debugging should go together with resource monitoring, I would say. Because it is possible that those crashing valloc, vfree system calls simply mean that memory ran out. But again, I know nothing what Windows does.

Don't worry about your previous discussion. I placed a note there.
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