There are a few conditions for the Namenode to come out of safemode. # Number of datanodes, # Number of blocks that have been reported.
How many blocks have the datanodes reported? On Tue, Oct 4, 2016 at 1:22 PM, Steve Brenneis <swb102...@gmail.com> wrote: > I have an HDFS cluster of three nodes. They are all running on Amazon EC2 > instances. I am using HDFS for an HBase backing store. Periodically, I will > start the cluster and the name node stays in safe mode because it says the > number of live datanodes has dropped to 0. > > The number of live datanodes 2 has reached the minimum number 0. Safe mode > will be turned off automatically once the thresholds have been reached. > > The datanode logs appear to be normal, with no errors indicated. The > dfsadmin report says the datanodes are both normal and that the name node > is in contact with them. > > Safe mode is ON > Configured Capacity: 16637566976 (15.49 GB) > Present Capacity: 7941234688 (7.40 GB) > DFS Remaining: 7940620288 (7.40 GB) > DFS Used: 614400 (600 KB) > DFS Used%: 0.01% > Under replicated blocks: 0 > Blocks with corrupt replicas: 0 > Missing blocks: 0 > Missing blocks (with replication factor 1): 0 > > ------------------------------------------------- > Live datanodes (2): > > Name: 172.31.52.176:50010 (dev2) > Hostname: dev2 > Decommission Status : Normal > Configured Capacity: 8318783488 (7.75 GB) > DFS Used: 307200 (300 KB) > Non DFS Used: 3257020416 (3.03 GB) > DFS Remaining: 5061455872 (4.71 GB) > DFS Used%: 0.00% > DFS Remaining%: 60.84% > Configured Cache Capacity: 0 (0 B) > Cache Used: 0 (0 B) > Cache Remaining: 0 (0 B) > Cache Used%: 100.00% > Cache Remaining%: 0.00% > Xceivers: 1 > Last contact: Tue Oct 04 15:47:00 EDT 2016 > > > Name: 172.31.63.188:50010 (dev1) > Hostname: dev1 > Decommission Status : Normal > Configured Capacity: 8318783488 (7.75 GB) > DFS Used: 307200 (300 KB) > Non DFS Used: 5439311872 (5.07 GB) > DFS Remaining: 2879164416 (2.68 GB) > DFS Used%: 0.00% > DFS Remaining%: 34.61% > Configured Cache Capacity: 0 (0 B) > Cache Used: 0 (0 B) > Cache Remaining: 0 (0 B) > Cache Used%: 100.00% > Cache Remaining%: 0.00% > Xceivers: 1 > Last contact: Tue Oct 04 15:47:00 EDT 2016 > > If I force the name node out of safe mode, the fsck commmand says that the > file system is corrupt. When this happens, the only thing I've been able to > do to get it back is to format the HDFS file system. I have not changed the > configuration of the cluster. This just randomly seems to occur. The system > is in development, but this will be unacceptable in production. > I’m using version 2.7.3. Thank you in advance for any help. > >
