BLOCKS WRITTEN / READ

Blocks Written

The rate or number of blocks written to a DataNode.

Blocks Read

The rate or number of blocks read from a DataNode.

FSYNCH TIME / NUM OPS

Fsynch Time

Average fsync time.

Fsynch Num Ops

Total number of fsync operations.

DATA PACKETS BLOCKED / NUM OPS

Data Packet Blocked Time

Indicates the avarage waiting time of transfering a data packet on a DataNode.

Data Packet Blocked Num Ops

Indicates the number of data packets transferred on a DataNode.

PACKET TRANSFER BLOCKED / NUM OPS

Packet Transfer Time

Average transfer time of sending data packets on a DataNode.

Packet Transfer Num Ops

Indicates the number of data packets blocked on a DataNode.

NETWORK ERRORS / GC COUNT

Network Errors

Rate of network errors on JVM.

GC Count

Garbage collection DataNode hits.

GC TIME / GC TIME PARNEW

GC Time

JVM garbage collection time on a DataNode.

GC Time ParNew

Young generation (ParNew) garbage collection time on a DataNode.