Bug 1331341

Summary: Apache can not cache content if Expires header is modified
Product: Red Hat Enterprise Linux 7 Reporter: kudlacak1
Component: httpdAssignee: Luboš Uhliarik <luhliari>
Status: CLOSED ERRATA QA Contact: Martin Frodl <mfrodl>
Severity: high Docs Contact:
Priority: urgent    
Version: 7.2CC: dmasirka, isenfeld, jorton
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: httpd-2.4.6-42.el7 Doc Type: Bug Fix
Doc Text:
In a caching proxy configuration, the mod_cache module would treat content as stale if the Expires header changed when refreshing a cached response. As a consequence, an origin server returning content without a fixed Expires header would not be treated as cacheable. The mod_cache module has been fixed to ignore changes in the Expires header when refreshing content. As a result, such content is now cacheable, improving performance and reducing load at the origin server.
Story Points: ---
Clone Of:
: 1347648 (view as bug list) Environment:
Last Closed: 2016-11-04 08:10:50 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1347648    

Description kudlacak1 2016-04-28 10:36:17 UTC
Description of problem:
If apache is configured as forward caching proxy, it is not serving some responses from cache as it should. After receiving "Not modified" response from remote server with modified Expires header, apache makes another request to remote server, instead of serving content from cache. It is fixed by: https://github.com/apache/httpd/commit/fa30ab4caea3050fee88457e56aad65fecdcfa57. I suggest backporting this.

Version-Release number of selected component (if applicable):
Apache 2.4.6


Actual results:
Content is not served from cache.

Expected results:
Content is served from cache

Comment 2 Joe Orton 2016-04-28 14:46:25 UTC
Thanks for the report.  Please submit a support ticket referencing this bug if this is a problem for you in production and you'd like it fixed in a future RHEL7 update.

Comment 13 errata-xmlrpc 2016-11-04 08:10:50 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHEA-2016-2534.html