mysql-proxy-discuss team mailing list archive

[Adrienne Porter Felt <apf@xxxxxxxxxxxx>]

A note:

if we increase the result set size for a SELECT statement by increasing the
> size of the table, eventually (around 7000) they are faster, too.
>  (resultSetSize.png shows that data.)
>

That chart measures the % of overall time that the proxy is responsible for.
 So, we expect it to decrease to close to zero as the result set increases,
because the query itself is taking longer (so the proxy takes less time
relative to the overall time).  But then we don't expect it to ever get
negative, because that means we're *improving* performance.



>
>
> On Fri, Sep 4, 2009 at 12:02 PM, Giuseppe Maxia <g.maxia@xxxxxxxxx> wrote:
>
>> Hi,
>> really puzzling indeed.
>> * Can you share the query that was faster under Proxy?
>> * Did you check if the results were the same in both cases?
>> * Could it be that the query through Proxy was cached?
>>
>> Cheers
>>
>> Giuseppe
>>
>> On Fri, Sep 4, 2009 at 8:50 PM, Adrienne Porter Felt<apf@xxxxxxxxxxxx>
>> wrote:
>> > Hi everyone,
>> > I've come across a puzzling discovery while trying to test a baseline.
>> >  Here's our setup: we make a connection from a python script to a local
>> > MySQL database through MySQL Proxy.  We're using MySQL proxy with the
>> funnel
>> > modification (but I'm not sure that matters).  We are sure our queries
>> are
>> > actually going through the proxy to the database (they aren't being
>> > reflected back by a Lua script).
>> > Bizarrely enough, some of our queries are running FASTER with MySQL
>> Proxy in
>> > the middle than if we were just directly connecting to the database.
>>  This
>> > doesn't seem to make sense -- the system with the proxy is doing
>> strictly
>> > more work.
>> > Does anyone know why this is happening?  Have you seen this before?
>>  We've
>> > gone over our measurement system repeatedly and can't find bugs (but of
>> > course there may still be bugs).  One thought is that MySQL Proxy is
>> loading
>> > some library it shares with MySQL into memory and thereby pre-fetching
>> the
>> > library for MySQL...but I don't know if that makes sense since the MySQL
>> > server is always running in the background anyway.
>> > We'd appreciate thoughts.
>> > Thanks!
>> > Adrienne
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>> >
>>
>>
>>
>> --
>> The Data Charmer
>> http://datacharmer.org/
>>
>
>