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From Chris Olver <chris.ol...@3plearning.com>
Subject RE: Apache Derby - Locks up.
Date Tue, 10 Jun 2014 08:41:47 GMT
Hi Brett,

Many thanks for your help, VisualVM showed up the issue and you were indeed correct.. It was
ignoring the commands of increasing the heap. I have now got a fresh version of the startNetworkService
and made the necessary changes. It now runs well.. One question from this experience, using
VisualVM I can see over multiple hours the HeapSpace continues to grow and doesn't garbage
collect. Is there a setting or timer which can garbage collect the heap more frequently? 
Kind regards,

Chris Olver

-----Original Message-----
From: Bergquist, Brett [mailto:BBergquist@canoga.com] 
Sent: 06 June 2014 23:21
To: Derby Discussion
Subject: RE: Apache Derby - Locks up.

Maybe connect up with jvisualvm to the process and see what it is reporting.    Jvisualvm
will show the environment of the process.    Since you are specifying both a -Xmx and -Xms,
the heap should be initially allocated to your 6G and never grow or shrink.  Jvisualvm will
show if that is it is doing so.

It seems strange that it is requiring so much memory.   Yes your row count is high but I have
tables in my database that are regularly 10M records that are queried every 5 minutes with
no issue and I can do so with a much smaller memory setting (4G is what I am using in testing).

Derby can work in an environment like this as one system that we have has tables that are
inserted into about 10M records/day with no issues.

-----Original Message-----
From: Chris Olver [mailto:chris.olver@3plearning.com] 
Sent: Thursday, June 05, 2014 11:42 PM
To: Derby Discussion
Subject: RE: Apache Derby - Locks up.

Just before it locked up, I managed to get this:

--- Derby Network Server Runtime Information ---
---------- Session Information --------------- Session # :4 Database :etl User :a # Statements:1
Prepared Statement Information:
        Stmt ID         SQLText
        -------------   -----------

Session # :19

# Connection Threads : 2
# Active Sessions : 2
# Waiting  Sessions : 0

Total Memory : 3042443264       Free Memory : 153934376

So I'm not sure what heap size it is reaching. 



-----Original Message-----
From: Bryan Pendleton [mailto:bpendleton.derby@gmail.com]
Sent: 06 June 2014 12:32
To: Derby Discussion
Subject: Re: Apache Derby - Locks up.

It's interesting that you are trying to set it to use 6 G, and yet in your other message there
was the line:

 > Total Memory : 1756889088       Free Memory : 306272128

which seems to indicate that it's only using 1.7 GB.

Like maybe you're running a 32 bit JVM, not a 64 bit JVM, somehow?


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