[HDFS-3256] HDFS considers blocks under-replicated if topology script is configured with only 1 rack

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.0-alpha, 0.23.7
• Target Version/s: 2.0.0-alpha
• Hadoop Flags: Reviewed
• Assignee: Aaron Myers
• Reporter: Aaron Myers
• Created: 11/Apr/12 21:32
• Updated: 28/Sep/15 20:58
• Resolved: 12/Apr/12 21:32

Description

HDFS treats the mere presence of a topology script being configured as evidence that there are multiple racks. If there is in fact only a single rack, the NN will try to place the blocks on at least two racks, and thus blocks will be considered to be under-replicated.

Issue Links

• is related to: HDFS-3267 TestBlocksWithNotEnoughRacks races with DN startup
• is related to: HDFS-3266 DFSTestUtil#waitCorruptReplicas doesn't sleep between checks
• relates to: HDFS-15 Rack replication policy can be violated for over replicated blocks