Ben Borchard created HBASE-18597:
------------------------------------
Summary: ExportSnapshot tool is closing a FileSystem object
obtained from the cache
Key: HBASE-18597
URL: https://issues.apache.org/jira/browse/HBASE-18597
Project: HBase
Issue Type: Bug
Components: snapshots
Reporter: Ben Borchard
In the ExportSnapshot tool the input and output FileSystem objects are being
obtained using the method _FileSystem.get_ which will either create a new
FileSystem object or simply take an existing object out of the cache if a
suitable one exists.
After it is done with the these FileSystem objects it will close them.
The issue here is that the ExportSnapshot tool will potentially remove
preexisting FileSystem objects from the cache by closing said objects. This
will break any apis running in the same process that are relying on these
cached FileSystem objects.
A simple solution could, I believe, fix this problem without affecting the
functionality of the ExportSnapshot tool:
Change ExportSnapshot.java lines 943:
{{FileSystem inputFs = FileSystem.get(inputRoot.toUri(), srcConf);}}
and 947:
{{FileSystem outputFs = FileSystem.get(outputRoot.toUri(), destConf);}}
to use _FileSystem.newInstance_ instead of _FileSystem.get_:
943
{{FileSystem inputFs = FileSystem.newInstance(inputRoot.toUri(), srcConf);}}
947
{{FileSystem outputFs = FileSystem.newInstance(outputRoot.toUri(), destConf);}}
This will create a unique entry in the cache and in this way prevent the
closure of these FileSystem objects from wiping out any preexisting FileSystem
objects. It will also ensure that no unused FileSystem objects created by the
ExportSnapshot tool will be left taking up heap space and potentially causing
memory issues.
I am happy to submit a fix for this, but figured I would open an issue first so
the issue can be properly discussed and tracked.
Also note this is the first issue I have opened so I apologize in advance for
any standard procedures and/or best practices I haven't followed.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
