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MapR-DB table region sizes over limit?

Question asked by john.humphreys on May 15, 2017
Latest reply on May 15, 2017 by jbubier

I'm using OpenTSDB against MapR-DB (OpenTSDB probably isn't overly relevant to the question though).  

 

When analyzing the main table's regions, I can see that nearly half of them are over the region size of 4GB, and quite a few are ending up to 5.6GB.  The largest one so far is 5.8GB.

 

Note that this is all based on physical size.  I have LZ4 compression enabled and auto-split enabled.  The logical table sizes are up to 11GB.

 

  1. Is this expected?  If so, what's the upper bound on what the table size can actually be?  When exactly is the auto-splitting enabled to bring the region size back down?
  2. I know MapR-DB has a lot of architectural improvements over HBase.  If I set a smaller region size (e.g. 1GB), will it tend to help or hurt my lookup performance?
  3. Can I change the region size of a table that already has data (and is it okay to do)?

 

Thanks,

 

-John Humphreys

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