On 05/11/2008, at 4:36 AM, Michael McCandless wrote:
If possible, you should try to use a larger corpus (eg Wikipedia) rather than multiply Reuters by N, which creates unnatural term frequency distribution.

I'll replicate the tests with the wikipedia corpus over the next few days and regenerate the graphs to show the data points in addition to the curves. The data I am using comes from the output on the benchmark framework:

[java] Operation round mrg runCnt recsPerRun rec/s elapsedSec avgUsedMem avgTotalMem [java] UnoptSearch_100_Par 0 2 1 100 230.4 0.43 29,517,680 44,834,816

I am plotting the "rec/s" which I am (possibly mistakenly) interpreting to mean "searches per second" as I asked for 100 searches and it took 0.43 seconds to perform them all.

It's best to use a real query log, if possible, to run the queries. If you are expecting your production machines to have plenty of RAM to hold the index, then you should definitely run the queries through once, discard it, to get all stuff loaded in RAM including the OS caching all required data in its IO cache.

Not opening/closing a reader per search should change the graphs quite a bit (for the better) and hopefully change some of the odd things you are seeing (in the questions below).

I don't believe our large users to have enough memory for Lucene indexes to fit in RAM. (Especially given we use quite a bit of RAM for other stuff.) I think we also close readers pretty frequently (whenever any user updates a JIRA issue, which I am assuming happening nearly constantly when you've got thousands of users). I was trying to mimic our usage as closely as I could to see whether Lucene behaves pathologically poorly given our current architecture. There have been some excellent suggestions about using in-memory indexes for recent updates but changes of that kind are, unfortunately, currently outside of my purview :-(

Given that our current usage may be suboptimal :-/ does anyone have any ideas about what may be causing the anomalies I identified earlier?

Cheers,
Justus

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to