On 1/13/2015 10:35 AM, David Smith wrote:
> I have a query against a single 50M doc index (175GB) using Solr 4.10.2, that
> exhibits the following response times (via the debugQuery option in Solr
> Admin):
> "process": {
> "time": 24709,
> "query": { "time": 54 }, "facet": { "time": 24574 },
>
>
> The query time of 54ms is great and exactly as expected -- this example was a
> single-term search that returned 3 hits.
> I am trying to get the facet time (24.5 seconds) to be sub-second, and am
> having no luck. The facet part of the query is as follows:
>
> "params": { "facet.range": "eventDate",
> "f.eventDate.facet.range.end": "2015-05-13T16:37:18.000Z",
> "f.eventDate.facet.range.gap": "+1DAY",
> "start": "0",
>
> "rows": "10",
>
> "f.eventDate.facet.range.start": "2005-03-13T16:37:18.000Z",
>
> "f.eventDate.facet.mincount": "1",
>
> "facet": "true",
>
> "debugQuery": "true",
> "_": "1421169383802"
> }
>
> And, the relevant schema definition is as follows:
>
> <field name="eventDate" type="tdate" indexed="true" stored="true"
> multiValued="false" docValues="true"/>
>
> <!-- A Trie based date field for faster date range queries and date
> faceting. -->
> <fieldType name="tdate" class="solr.TrieDateField" precisionStep="6"
> positionIncrementGap="0"/>
>
>
> During the 25-second query, the Solr JVM pegs one CPU, with little or no I/O
> activity detected on the drive that holds the 175GB index. I have 48GB of
> RAM, 1/2 of that dedicated to the OS and the other to the Solr JVM.
>
> I do NOT have any fieldValue caches configured as yet, because my (perhaps
> too simplistic?) reading of the documentation was that DocValues eliminates
> the need for a field-level cache on this facet field.
24GB of RAM to cache 175GB is probably not enough in the general case,
but if you're seeing very little disk I/O activity for this query, then
we'll leave that alone and you can worry about it later.
What I would try immediately is setting the facet.method parameter to
enum and seeing what that does to the facet time. I've had good luck
generally with that, even in situations where the docs indicated that
the default (fc) was supposed to work better. I have never explored the
relationship between facet.method and docValues, though.
I'm out of ideas after this. I don't have enough experience with
faceting to help much.
Thanks,
Shawn
