685730 - Mindtouch Cache Options

Status: RESOLVED FIXED

(developer.mozilla.org Graveyard :: Wiki pages, defect)

Description

[Jake Maul [:jakem]]

While looking at the control panel / cache management page on devmo, I noticed the Cache Options section:

Disabled    Caching will be disabled.
Request    Cached objects expire at the end of each request.
Instance    Cached objects are shared between requests.
Memcache    Cached objects are managed externally by memcache and may be shared with multiple instances. (Available for licensed multi-server setups)

We are currently running at "Request" level, which to my reading means cache objects are never shared between requests. This seems unlikely to give a significant boost in my mind.

The "Instance" level would mean cache objects would be shared throughout that whole Mono process... this is how things like PHP-APC or eAccelerator work. I think this would be safe for use, at least for testing on -stage9. We may want to speak with Mindtouch to see if there are any negative consequences to this... I'm not seeing a good reason *not* to use this, and that makes me wonder why the "Request" level even exists.

"Memcache" requires an extra license from Mindtouch, but might be worthwhile. Cache objects would be shared among all 3 servers. Additionally, this memcached server could be used in the django app as well. We should at least ask them what this might cost if it seems at all interesting to you.

If we do end up with a separate indexer server (Bug 685681), and we do go for memcache, I would probably want them to share a server... seems like a fairly trivial combination, since there would be no interaction between them at all, and we could easily scrounge up a bit of extra RAM for memcache to use.

Comment 1

[Luke Crouch [:groovecoder]]

Good idea. Sheppy, seems like a trivial change to try Instance on stage9 for a while and then try production? No code push required; just play with the dial.

Comment 2

[Eric Shepherd [:sheppy]]

Yeah, we can try that. For the record, we ran into problems with using anything but "Request" in the past, but that was with the badly busted-up Lucene situation, so it may be better now. I will change it to "Instance" on stage right now.

And it's done.

Comment 3

[Eric Shepherd [:sheppy]]

Also, I'm disinclined to bother with memcache if we need to pay extra for it, given that we hope to be done with MindTouch in a few months.

Comment 4

[John Karahalis [:openjck]]

Replaced Mindtouch with Kuma. Marking as fixed.