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Accumulo >> mail # user >> Efficient Tablet Merging [SEC=UNOFFICIAL]

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Efficient Tablet Merging [SEC=UNOFFICIAL]

I have a table that we create splits of the form yyyymmdd-nnnn where nnnn ranges from 0000 to 0840.  The bulk of our data is loaded for the current date with no data loaded for days older than 3 days so from my understanding it would be wise to merge splits older than 3 days in order to reduce the overall tablet count.  It would still be optimal to maintain some distribution of tablets for a day across the cluster so I'm looking at merging splits in 10 increments eg, merge -b 20130901-0000 -e 20130901-0009, therefore reducing 840 splits per day to 84.

Currently we have 120K tablets (size 1G) on a cluster of 56 nodes and our ingest has slowed as the data quantity and tablet count has grown.  Initialy we were achieving 200-300K, now 50-100K.

My question is, what is the best way to do this merge?  Should we use the merge command with the size option set at something like 5G, or maybe use the compaction command?

>From my tests this process could take some time so I'm keen to understand the most efficient approach.

Thanks in advance,
Matt Dickson