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Type:
Bug
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Status: Closed
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Priority:
Critical
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Resolution: Fixed
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Affects Version/s: 0.23.4, 2.0.2-alpha
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Fix Version/s: 2.0.3-alpha, 0.23.5, 0.23.6
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Component/s: namenode
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Labels:None
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Target Version/s:
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Hadoop Flags:Reviewed
As pointed out in HDFS-4183, when the lease monitor calls internalReleaseLease(), it acquires the namespace write lock. Inside internalReleaseLease(), if a block recovery is needed, the lease is reassigned to the namenode itself and this is logged & synced in logReassignLease().
Since this is done while the write lock is held, log syncing is blocked. When a large number of leases are expired and blocks are recovered, namenode can slow down.