The Heatmaps view gives you a graphic representation of the overall utilization of your cluster using simple color coding.
Each host in the cluster is represented by a block. To see more information on a specific host, hover over the block you are interested in, and a popup with key host data appears. The color of the blocks represents usage in an appropriate unit based on a selectable set of metrics. If the data necessary to determine state are not all available, the block is marked as having Invalid Data. Changing the default maximum values for the heatmap lets you fine tune the representation. Use the Select Metric dropdown to select the metric type.
Currently the following metrics are supported:
| Metric | Uses |
| Host/Disk Space Used % | disk.disk_free and disk.disk_total |
| Host/Memory Used % | memory.mem_free and memory.mem_total |
| Host/CPU Wait I/O % | cpu.cpu_wio |
| HDFS/Bytes Read | dfs.datanode.bytes_read |
| HDFS/Bytes Written | dfs.datanode.bytes_written |
| HDFS/Garbage Collection Time | jvm.gcTimeMillis |
| HDFS/JVM Heap MemoryUsed | jvm.memHeapUsedM |
| YARN/Garbage Collection Time | jvm.gcTimeMillis |
| YARN / JVM Heap Memory Used | jvm.memHeapUsedM |
| YARN / Memory used % | UsedMemoryMB and AvailableMemoryMB |
| HBase/RegionServer read request count | hbase.regionserver.readRequestsCount |
| HBase/RegionServer write request count | hbase.regionserver.writeRequestsCount |
| HBase/RegionServer compaction queue size | hbase.regionserver.compactionQueueSize |
| HBase/RegionServer regions | hbase.regionserver.regions |
| HBase/RegionServer memstore sizes | hbase.regionserver.memstoreSizeMB |
