When updating partition metadata as part of COMPUTE STATS we would previously
attempt to update all partitions at once. This could lead to HMS socket timeouts
and also could run into issues if there were > 32K partitions.
In this change we now update the partitions in batches, with a max size of 500
partitions per batch. We also compare whether the row count has changed and only
update partitions that have been modified.
Change-Id: If7bfcc30f86fc2fdd79855b981067ac29a47b5e1
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1913
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: jenkins
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1918
This updates how Impala fetches partition metadata from the Hive Metastore to fetch
partitions in batches, rather than all at once. This helps reduce the load on the
HMS and also lets Impala scale to above 32K partitions. The downside is that it
may require additional RPCs to get all the partitions.
This is done by first querying the metastore to get all the partition names that
exist, then splitting the list of names into seperate batches to get the actual
partition metadata.
Impala uses a default size of 1000 partitions per batch, but it can be configured
by setting the 'hive.metastore.batch.retrieve.table.partition.max' parameter
in the hive-site.xml config file.
Change-Id: Ide0ec30ef8a9e00f79c26551aa8e5e7814c73034
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1662
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: jenkins
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1698
