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From Knut Anders Hatlen <knut.hat...@oracle.com>
Subject Re: Derby.properties not functioning for replication setting?
Date Mon, 22 Apr 2013 08:44:28 GMT
ping wei <pingweitan@gmail.com> writes:

> Replication confirm is functioning as after failover replication ( properly
> shutdown ), able to see table updated. 
>
> However, if i waited a minute up to 10 minute, cut off the connection (
> shutdown slave derby service ) then connect again ( turn on slave derby
> service ), i dont see any table udpate at all. ( if interval is working here
> )

Hi,

I think the max log shipping interval only makes sure the logs have been
sent to the slave, and not that the slave has actually stored the logs
to disk by that time. It sounds like you performed fail-over by shutting
down the slave, and then the slave may lose transactions that it still
hasn't stored to disk, even if it has the logs for those transactions in
its buffers.

Derby's replication service was designed to allow the slave to take over
if the master goes down. In the experiment you described, it was the
slave that went down rather than the master. The replication service
doesn't ensure that the slave database is up to date with the master in
this case. However, the master database should still have all the data.

Hope this helps,

-- 
Knut Anders

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