Bug #75488 [Opn]: Under heavy load PHP misses Opcache hits with no errors

From: Date: Fri, 27 Apr 2018 15:28:28 +0000
Subject: Bug #75488 [Opn]: Under heavy load PHP misses Opcache hits with no errors
References: 1  Groups: php.bugs 
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Edit report at https://bugs.php.net/bug.php?id=75488&edit=1

 ID:                 75488
 Updated by:         nikic@php.net
 Reported by:        david at davidfavor dot com
 Summary:            Under heavy load PHP misses Opcache hits with no
                     errors
 Status:             Open
 Type:               Bug
 Package:            opcache
 Operating System:   Ubuntu Artful
 PHP Version:        7.2.3
 Block user comment: N
 Private report:     N

 New Comment:

It's not immediately obvious to me that there is any bug here. Why do you think that any log
entry without 0.00% CPU usage indicates an opcache miss? Execution time and CPU load vary and your
99-percentile load is going to be significantly higher than your average load. Especially as opcache
itself only reports 2 misses, I'd assume that at least this particular case is simply due to
statistical variation.

Now, the actual production case you describe does look like an actual problem. This kind of behavior
should not occur during normal operation, but this would be fairly typical during an opcache
restart. Do these occurrences coincide with anything that could trigger an opcache reset (files
being deployed, fpm reloaded, etc.)?


Previous Comments:
------------------------------------------------------------------------
[2018-03-26 14:28:55] david at davidfavor dot com

Bug persists.

Bumping PHP level.

------------------------------------------------------------------------
[2018-03-07 13:51:23] david at davidfavor dot com

Problem still exists.

Bumping PHP + OS versions.

------------------------------------------------------------------------
[2018-01-15 16:06:45] david at davidfavor dot com

This is a huge problem for high traffic sites using PHP for dynamic content generation.

Be great if someone knowledgable about Opcache could take a look at this + determine a fix or work
around.

Thanks.

------------------------------------------------------------------------
[2018-01-15 16:05:12] david at davidfavor dot com

Bumping version to 7.2.1 as problem still exits.

------------------------------------------------------------------------
[2017-12-06 18:18:05] david at davidfavor dot com

IP has changed to 144.217.34.13 for PHP-7.2 container.

------------------------------------------------------------------------


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