Enable disk IO statistics
Disk IO statistics are disabled by default. To enable disk IO statistics, you must
set the file IO sampling percentage to a non-zero value in the
hdfs-site.xml
file.
Disk IO statistics are disabled by default. To enable disk IO statistics, you must
set the file IO sampling percentage to a non-zero value in the
hdfs-site.xml
file.
dfs.datanode.fileio.profiling.sampling.percentage
property to a non-zero value in hdfs-site.xml
.
<property>
<name>dfs.datanode.fileio.profiling.sampling.fraction</name>
<value>25</value>
</property>
Note | |
---|---|
Sampling disk IO might have a minor impact on cluster performance. |
http://<namenode_host>:50070/jmx
.
"name" : "Hadoop:service=DataNode,name=DataNodeVolume-/data/disk2/dfs/data/",
"modelerType" : "DataNodeVolume-/data/disk2/dfs/data/",
"tag.Context" : "dfs",
"tag.Hostname" : "n001.hdfs.example.com",
"TotalMetadataOperations" : 67,
"MetadataOperationRateAvgTime" : 0.08955223880597014,
...
"WriteIoRateNumOps" : 7321,
"WriteIoRateAvgTime" : 0.050812730501297636