Use the HBase web UI to determine if one region or regionserver if being overloaded with requests compared to another while running your pig job. You can also examine the number of regions (and their splits) via this UI. You can reach this page via the Ambari HBase service page's "Quick Links" menu. ... View more

Please provide more information about the error. Ambari-server log (with any exceptions), what the UI says, how you got this error, etc. ... View more

Yep, you're exactly right @Ravi Mutyala. Accumulo increases the default replication on these files to 5 to guard against catastrophic failure resulting in data loss. You can either ignore it, or reduce it by hand via the setrep command. ... View more

Any chance you can edit your question to include the complete Java stack trace, please? ... View more

"where (regexp_split(CDC."key",',')[1]) > TO_CHAR((TO_NUMBER(NOW())-60000)" You want to be doing the regexp_split on the TO_CHAR side of that expression, not the key side. Like Ankit pointed out, TO_CHAR is putting the commas in the number while your key does not have commas. However, a comma sorts before all of the numbers so I would have thought that you would get all records (instead of none). Still, I think I would try fixing your WHERE clause to make sure you comparing numbers without commas on both sides of the expression. ... View more

Can you share your table schema, please? Also, it might help you to do something like the following to help debug select key, TO_CHAR(TO_NUMBER(NOW())-600000) from CDC; ... View more

The leading space in your JDBC url is likely problematic. If that doesn't fix it, you should provide the error you are experiencing. ... View more

I was recently in a discussion with @Rajeshbabu Chintaguntla about this. If your table size is relatively small compare to the amount of block cache you have available (e.g. if you can cache your entire table), it makes sense to limit the number of salt-buckets to the number of region servers you have (similar to Jeremy's recommendation). However, once you start getting much larger tables, ones that will definitely not fit into cache and would require disk access, you're going to benefit by having more buckets available to distribute the load across multiple regions per server. I believe the consensus we had there was that something along the lines of 64 to 128 salt buckets would be a good starting point for 10's of region servers. Obviously, this depends a lot on the number of region servers you're using too and the other users of HBase. If you're the only one using a 50node HBase cluster, the recommendations would be vastly different than one of 10 users using a 25node HBase cluster. "It depends" 🙂 ... View more