QTime in microsecond

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QTime in microsecond

iorixxx
Is there a way to get QTime in microsecond from solr?

I have small set of collection and my response time (QTime) is 0 or 1 milliseconds. I am running benchmark tests and I need more sensitive running times for comparision.

Thanks for your help.


     
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RE: QTime in microsecond

Feak, Todd
The easiest way is to run maybe 100,000 or more queries and take an
average. A single microsecond value for a query would be incredibly
inaccurate.

-ToddFeak



-----Original Message-----
From: AHMET ARSLAN [mailto:[hidden email]]
Sent: Friday, January 23, 2009 1:33 AM
To: [hidden email]
Subject: QTime in microsecond

Is there a way to get QTime in microsecond from solr?

I have small set of collection and my response time (QTime) is 0 or 1
milliseconds. I am running benchmark tests and I need more sensitive
running times for comparision.

Thanks for your help.


     

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RE: QTime in microsecond

hossman
: The easiest way is to run maybe 100,000 or more queries and take an
: average. A single microsecond value for a query would be incredibly
: inaccurate.

that can be useful for doing the timing externally, if you're interested
in averaging over all X queries in a sequential batch, but it doesn't help
with things like replaying a live log (so you see acurate cache
behavior) and then trying to evaluate wether a subset of those queries
(the ones that use faceting maybe) are faster with config X then with
config Y .. for that you really want to be able to crunch the logs to
extract just hte requests you are interested in and then generate stats --
but as Ahmet points out, with millisecond resolution soemthing that takes
about 1 millisecond is hard to profile for possible improvements.

with the Solr code as written the best suggestion i can make is to see if
your servlet container can log it's requests at microsecond resolution --
that will include the ResponseWriter timing and the network overhead, but
that may better anyway.

A patch to change Solr to use System.nanoTime() for all the internal
timein would probably be pretty straight forward -- we'd just have to
consider wether it will screw people up if we change the format that gets
logged or included in teh response.


-Hoss