On 11/10/2011 11:55 AM, Shawn Heisey wrote:
Do Solr's LRU caches pay attention to hitcount when deciding which
entries to age out and use for autowarming, or is it purely based on
the last time that entry was touched? Is it a reasonable idea to come
up with an algorithm that uses hitcount along with entry age, ideally
with a configurable weight value?
I'm asking because I have really nasty filter queries that make for
very slow autowarming of the filterCache. I've had to drop my
autowarmCount on the filterCache to 4, and warming that cache can
still take 30-60 seconds. Sometimes it's very fast, as low as 3 seconds.
Although I don't have statistics to back my claim, I suspect that the
really nasty filters don't have as high a hitcount as the ones that
are more simple. Typically the really nasty filters are used when an
employee logs into the site. Employees have access to a lot more than
customers do, but the search still needs to be filtered to be
appropriate for whatever search options are active.
If hitcount could be examined as well as entry age, I think that it
could do a better job of selecting entries for warming, and I could
use more than 4.
Replying to myself ... not surprisingly, I've just discovered that such
a beast DOES exist. I've opened a jira issue, SOLR-2889.
http://en.wikipedia.org/wiki/Adaptive_Replacement_Cache
Thanks,
Shawn
