HDFS DataNodes
Metrics to see status for the DataNodes.
| Row | Metrics | Description |
|---|---|---|
| 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 average 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. |