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Date: Fri, 9 Jun 2006 22:47:11 -0700
From: "Andrew McIntyre" <mcintyre.a@gmail.com>
To: "Derby Discussion" <derby-user@db.apache.org>
Subject: Re: Derby hogging CPU on startup
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 <2606C38685A4FC4AAEB1E0B7963DF75301EF0599@ES22SNLNT.srn.sandia.gov>
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References: 
 <2606C38685A4FC4AAEB1E0B7963DF75301EF0599@ES22SNLNT.srn.sandia.gov>

On 6/9/06, Mueller, Stephen Ng <snmuell@sandia.gov> wrote:
>
> I am using emdedded Derby for one of my applications.  After calling
> connection.open() on the database, the connection is returned promptly with
> no problem.

What API is the connection.open() method from? It's not a JDBC method.

> However, after this, my CPU usage goes to nearly 100%, and my
> computer slows down.  I can perform inserts on the database while this is
> happening, but they take a while.  Is Derby going through some sort of start
> up procedure?

Derby start up, even on an underpowered desktop by today's standards
(where underpowered = 400 Mhz P3 or 450 Mhz G4) Derby startup
shouldn't take more than 10 seconds, even when creating a new
database.

> Should it be taking up this much CPU?  It takes about a
> minute or so before completing, and my CPU usage returns to normal.

No, I don't think this is normal, and I have not experienced this
behavior before. When starting Derby, there is usually an initial
spike, though not even to 100% in most cases, and then CPU usage
quickly returns to normal.

What platform and JVM are you using? Perhaps there is something odd
going on with the JVM here.

How much RAM do you have? Perhaps the machine is running out of
physical memory and there is an excessive amount of access to virtual
memory?

> Anyone know why this is happening and how/if I can alleviate the problem?  FYI, I
> am using Derby 10.1.2.1.

Nothing recent rings a bell. I've seen CPU spikes in the past, but not
recent past - back in the JDK 1.1-era. Any additional details
concerning your setup and how you are accessing Derby might be useful
in tracking down the problem.

Thanks,
andrew