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From Alan Burlison <Alan.Burli...@sun.com>
Subject Re: Derby replication failed under heavy load
Date Fri, 24 Jul 2009 16:45:54 GMT
Andrew Lawrenson wrote:

> I'm not sure if it's the exact same issue, but I have observed the
> replication failing under heavy load where the replication buffers
> would fill faster than the logs can be shipped to the slave (even
> with fast servers & fast network). I've previously tweaked a copy of
> derby to allow up to 100 buffers (rather than the current max of 10),
> and optimized the various thresholds, but still observed over 80
> buffers being used under high load (this was with on
> Solaris).

I think it is the same issue - I saw an errors in the master log that 
mentioned something about the buffers filling up.  The thing that seems 
to trigger it is doing a number of whole-table deletes, presumably 
because while that's being processed on the slave the master is still 
chugging along writing more log records.

What I don't understand is why the master isn't being throttled if the 
slave can't keep up.

Alan Burlison

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