This version of 0.90.x HBase can be started on data written by HBase 0.20.x or HBase 0.89.x. There is no need of a migration step. HBase 0.89.x and 0.90.x does write out the name of region directories differently -- it names them with a md5 hash of the region name rather than a jenkins hash -- so this means that once started, there is no going back to HBase 0.20.x.
Be sure to remove the
directory on upgrade. A 0.20.x version of this file will have
sub-optimal configurations for 0.90.x HBase. The
hbase-default.xml file is now bundled into the
HBase jar and read from there. If you would like to review
the content of this file, see it in the src tree at
see Section 18.104.22.168, “HBase Default Configuration”.
Finally, if upgrading from 0.20.x, check your
.META. schema in the shell. In the past we would
recommend that users run with a 16kb
hbase> scan '-ROOT-' in the shell. This will output
.META. schema. Check
MEMSTORE_FLUSHSIZE size. Is it 16kb (16384)? If so, you will
need to change this (The 'normal'/default value is 64MB (67108864)).
Run the script
This will make the necessary edit to your
Failure to run this change will make for a slow cluster