Ming Ma created HDFS-7208:
-----------------------------
Summary: NN doesn't schedule replication when a DN storage fails
Key: HDFS-7208
URL: https://issues.apache.org/jira/browse/HDFS-7208
Project: Hadoop HDFS
Issue Type: Bug
Reporter: Ming Ma
We found the following problem. Somehow when a storage device on a DN fails, NN
continues to believe replicas of those blocks on that storage are valid and
doesn't schedule replication.
A DN has 12 storage disks. So there is one blockReport for each storage. When a
disk fails, # of blockReport from that DN is reduced from 12 to 11. Given
dfs.datanode.failed.volumes.tolerated is configured to be > 0, NN still
considers that DN healthy.
1. A disk fails. All blocks of that disk are removed from DN dataset.
{noformat}
...
2014-10-04 02:11:12,626 WARN
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl: Removing
replica BP-1748500278-xx.xx.xx.xxx-1377803467793:1121568886 on failed volume
/data/disk6/dfs/current
...
{noformat}
2. NN receives DatanodeProtocol.DISK_ERROR.
{noformat}
2014-10-04 02:11:12,681 WARN org.apache.hadoop.hdfs.server.namenode.NameNode:
Disk error on DatanodeRegistration(xx.xx.xx.xxx,
datanodeUuid=f3b8a30b-e715-40d6-8348-3c766f9ba9ab, infoPort=50075,
ipcPort=50020,
storageInfo=lv=-55;cid=CID-e3c38355-fde5-4e3a-b7ce-edacebdfa7a1;nsid=420527250;c=1410283484939):
DataNode failed volumes:/data/disk6/dfs/current
{noformat}
3. Run fsck on the file and confirm the NN's BlocksMap still has that replica.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
