[users@httpd] httpd mod_cache_disk shared by two servers

[Lorenzo Boccaccia <lo...@lookcast.com>]

I'm trying to get two servers using mod_cache_disk to share each other
cached files.

I got them to use the same share and use the same url > file using the
CacheKeyBaseURL directive, but while as long as I hit the same file on the
same server, I get caches hit, when I hit the file from the other server,
the cache entry gets cleaned up and recreated. then I get cache hits from
server 2 and if I get back from server 1 I get a cache miss there with
subsequent eviction


I've been trying to get them to accept each other file cleaning up headers
as I found them using the CacheIgnoreHeaders, but still comparing the files
shows at the beginning a variable part that is likely a verision format of
sort. both are docker images, so running an exact copy of the software
(Apache/2.4.6 (CentOS)), have their date synchronized and have the same
locale.



here's a sample from the same file that they won't accept from each other:
------

[root@lcks acache]# cat JKr/BG4/LTtnQJTokDJH7B1Q.header
*▒@▒y▒>▒@▒▒U▒{▒z▒>▒R▒▒>▒+7*
'CH▒3▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒https://<redacted>/imageViewer?r=default&b=81db379e-1045-4e21-b518-573734acd504-62c1118d-39ba-4b6f-a0d4-d758159441ee&thumb=trueServer:
Apache-Coyote/1.1
Last-Modified: Mon, 23 Sep 2019 21:06:01 GMT
Expires: Tue, 22 Sep 2020 21:06:01 GMT
X-Direct: missing
Content-Type: image/jpeg

Host: <redacted>
x-virtual-host: https://<redacted>/
X-Forwarded-Host: <redacted>
X-Forwarded-Server: <redacted>


[root@lcks acache]# cat JKr/BG4/LTtnQJTokDJH7B1Q.header
*▒▒t▒>▒▒.yX▒+▒p▒>▒▒▒v▒>▒`
*▒'CH▒3▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒https://<redacted>/imageViewer?r=default&b=81db379e-1045-4e21-b518-573734acd504-62c1118d-39ba-4b6f-a0d4-d758159441ee&thumb=trueServer:
Apache-Coyote/1.1
Last-Modified: Mon, 23 Sep 2019 21:06:50 GMT
Expires: Tue, 22 Sep 2020 21:06:50 GMT
X-Direct: missing
Content-Type: image/jpeg

Host: <redacted>
x-virtual-host: https://<redacted>/
X-Forwarded-Host: <redacted>
X-Forwarded-Server: <redacted>