Hi all,
After some performance testing on my HBase 0.20.1 development
environment (running in pseudo- and full-distributed mode on a single
laptop) I noticed that scanners do not get closed properly on the
region server. After creating a heap dump with Netbeans I can see the
StoreScanner instances are still in the Store.changedReaderObservers
collection.
Each StoreScanner instance has the "closed" flag set to false, so it
looks like the StoreScanner.close() method was never called.
I double-checked my client code and counted the number of times I
create and close a scanner, and these counts match. I also found this
is repeatable from the hbase shell. Open the shell, scan some table,
take a heap dump and you'll find an unclosed StoreScanner objects in
the Store.changedReaderObservers collection.
I've attached screenshots of the number of StoreScanner instances
(after 30.001 scans) and the Store.changedReaderObservers collection
of one of the Stores (notice that the closed field's value is 0 =>
false).
Ultimately the region server runs out of memory and crashes.
Has anyone experience similar problems?
Regards,
Erik
