Re: EmbeddedDriver performance help

From: Lachlan Deck (lachla..sh.com.au)
Date: Fri May 05 2006 - 00:03:56 EDT

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    Hi there,

    On 05/05/2006, at 12:15 PM, Jean T. Anderson wrote:

    > When using the Derby Network Client, is the client offloaded to
    > another
    > machine? or is it running on the same machine as the database?

    In both scenarios a single machine is used.

    > In embedded mode, are there any whimpers in the derby.log?

    No whimpers as such but is it intriguing that for each select it has
    the following cost running as embedded...

    2006-05-05 04:00:51,451 GMT Thread[Thread-12,5,main] (XID = 5935),
    (SESSIONID = 2), (DATABASE = directory:myDB), (DRDAID = null),
    Committing
    2006-05-05 04:00:51,529 GMT Thread[Thread-12,5,main] (XID = 5935),
    (SESSIONID = 2), (DATABASE = directory:myDB), (DRDAID = null),
    Committing
    2006-05-05 04:00:51,568 GMT Thread[Thread-12,5,main] (XID = 5935),
    (SESSIONID = 2), (DATABASE = directory:myDB), (DRDAID = null),
    Committing
    2006-05-05 04:00:51,635 GMT Thread[Thread-12,5,main] (XID = 5935),
    (SESSIONID = 2), (DATABASE = directory:myDB), (DRDAID = null),
    Executing prepared statement: SELECT t0.var1, t0.var2 <..> FROM
    Module t0 WHERE t0.someId = ? :End prepared statement with 1
    parameters begin parameter #1: 1587 :end parameter

    > --I could guess all night, but it might be faster for you to post to
    > derby-use..b.apache.org, and include the sysinfo output.

    Sure. Just thought I'd start here in case it was something particular
    about the default settings Cayenne uses to connect with.

    > The 2-3 hours vs 15 minutes is extremely curious.

    Very. I'd hazzard a guess at over-zealous locking/deadlocks. e.g.,
    Cayenne manually using transactions and derby using its own
    transactions internally by default perhaps...

    > -jean
    >
    > p.s. I'm on the derby project; haven't actually worked with cayenne
    > yet
    > but hope to free up time soon to dig in.

    Great.

    Lachlan Deck
    lachla..sh.com.au
    +61 2 9550 5001



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