Hi Matt, This is expected in Chukwa archives. When agent is unable to post to the collector, it will retry to post the same data again to another collector or retrys with the same collector when no other collector is available. Collector may have data written without proper acknowledge back to agent in high load situation. Chukwa philosophy is to retry until receiving acknowledgement. Duplicated data filter will be treated after data has been received.
The duplication filtering in Chukwa 0.3.0 depends on data loading to mysql. The same primary key will update to the same row to remove duplicates. It is possible to build a duplication detection process prior to demux which filter data based on sequence id + data type + csource (host), but this hasn't been implemented because primary key update method works well for my use case. In Chukwa 0.5, we are treating duplication the same as in Chukwa 0.3, where it will replace any duplicated row in HBase base on Timestamp + HBase row key. regards, Eric On Thu, Oct 21, 2010 at 8:22 PM, Matt Davies <[email protected]> wrote: > Hey everyone, > > I have a situation where I'm seeing duplicated data downstream before the > demux process. It appears this happens during high system loads and we are > still using the 0.3.0 series. > > So, we have validated that there is a single, unique entry in our source file > which then shows up a random amount of times before we see it in demux. So, > it appears that there is duplication happening somewhere between the agent > and collector. > > Has anyone else seen this? Any ideas as to why we are seeing this during high > system loads, but not during lower loads. > > TIA, > Matt > >
