From fb5391b1429f8602517d31ca14137b4e5891a645 Mon Sep 17 00:00:00 2001 From: Clark Boylan Date: Tue, 4 Apr 2017 09:03:56 -0700 Subject: [PATCH] Add info on reverse proxy caches This includes some basic info on the new mirror host reverse proxy caches for resources that aren't simple/easy/practical for proper mirroring. Change-Id: If71fa6bf1769ef82ab3a4d2c8a5e78005fc6d7e5 --- doc/source/afs.rst | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/doc/source/afs.rst b/doc/source/afs.rst index fc383c7264..abf6f2923e 100644 --- a/doc/source/afs.rst +++ b/doc/source/afs.rst @@ -398,3 +398,30 @@ If you need to remove a mirror, you can do the following: vos remove -server afs02.dfw.openstack.org -partition a -id mirror.foo +Reverse Proxy Cache +^^^^^^^^^^^^^^^^^^^ + +* `modules/openstack_project/templates/mirror.vhost.erb + `__ + +Each of the region-local mirror hosts exposes a limited reverse HTTP +proxy on port 8080. These proxies run within the same Apache setup as +used to expose AFS mirror contents. `mod_cache +`__ is used to +expose a white-listed set of resources (currently just RDO). + +Currently they will cache data for up to 24 hours (Apache default) +with pruning performed by ``htcacheclean`` once an hour to keep the +cache size at or under 2GB of disk space. + +The reverse proxy is provided because there are some hosted resources +that are not currently able to be practically mirrored. Examples of +this include RDO (rsync from RDO is slow and they update frequently) +and docker images (which require specialized software to run a docker +registry and then sorting out how to run that on a shared filesystem). + +Apache was chosen because we already had configuration management in +place for Apache on these hosts. This avoids management overheads of +a completely new service deployment such as Squid or a caching docker +registry daemon. +