426303 - A lot (most?) queries are not hitting memcache

Status: RESOLVED WORKSFORME

(addons.mozilla.org Graveyard :: Public Pages, defect)

Description

[Wil Clouser [:clouserw]]

While I was writing the patch for bug 425315 I was looking at what was actually hitting memcache and on some pages it's not much.  For example:

/en-US/firefox/
out of about 54 SELECT queries, only 32 hit memcache

/en-US/firefox/addon/4594
out of about 41 SELECT queries, only 20 hit memcache

/en-US/firefox/developers
out of about 345 queries, only 2 hit memcache

/en-US/firefox/developers/details/4594
out of about 73 queries, only 2 hit memcache

It looks like the majority of these, particularly on those developer pages, can be attributed to AppModel::findAll().  The first line checks for isset($this->name) and most of the time $this->name isn't set.  I'm tired so instead of digging into it, I'm filing this bug.  I think Laura wrote that stuff so I'm CCing her.

Comment 1

[Wil Clouser [:clouserw]]

Fred mentioned that developer pages bypass memcache on purpose which explains the last two.  The first two should be looked at though.

Comment 2

[Fred Wenzel [:wenzel]]

(In reply to comment #0)
> /en-US/firefox/
> out of about 54 SELECT queries, only 32 hit memcache

I cannot confirm this: When I load the page first, I get up to 200 queries. After two reloads, all relevant queries are cached, and only 3 queries are actually executed in order to build the page, all of which are related to the "recently updated" list in the bottom right corner of the page.

I shall investigate what's up with that, but in general, memcache is working for me as exepected.

Comment 3

[Fred Wenzel [:wenzel]]

That actually works as well, it just needs a few reloads until it is cached. My guess would be, memcached takes a few seconds to store it until it is able to return it when queried?