Details
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Bug
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Status: Closed
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Minor
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Resolution: Fixed
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2.0.3-alpha
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Reviewed
Description
When resources are low on the namenode, it enters SafeMode with a message like this:
14:00:10,666 WARN NameNodeResourceChecker:89 - Space available on
volume '/dev/hda1' is 104357888, which is below the configured
reserved amount 104857600
14:00:10,670 WARN FSNamesystem:3190 - NameNode low on available disk
space. Entering safe mode.
14:00:10,670 INFO StateChange:3836 - STATE* Safe mode is ON.
Resources are low on NN. Safe mode must be turned off manually.
However, turning off safe mode manually has no effect, since it immediately puts itself into Safe Mode again with a log message like this:
14:00:10,666 WARN NameNodeResourceChecker:89 - Space available on
volume '/dev/hda1' is 104357888, which is below the configured
reserved amount 104857600
14:00:10,670 WARN FSNamesystem:3190 - NameNode low on available disk
space. Entering safe mode.
14:00:10,670 INFO StateChange:3836 - STATE* Safe mode is ON.
Resources are low on NN. Safe mode must be turned off manually.
From the shell, it looks like this:
[cmccabe@vm1 h]$ ./bin/hdfs dfsadmin -safemode get Safe mode is ON [cmccabe@vm1 h]$ ./bin/hdfs dfsadmin -safemode leave Safe mode is OFF [cmccabe@vm1 h]$ ./bin/hdfs dfsadmin -safemode get Safe mode is ON
It seems like we should change the message about turning off safe mode manually, if turning off safe mode manually does not actually work for the case where resources are low. Probably we need to explain that safe mode should be turned off manually after adding more resources. As it is, the error message seems misleading.