1. For total memory configured you can check (impala daemon memory * a total number of demons ) , these values should be displayed on top of Impala admission control as well that this much if memory is allocated to the impala.
2. You can check other memory metrics from the cluster utilization report, please note that how much memory is consumed per pool feature is not currently captured in impala metrics.
a) Max Allocated
Peak Allocation Time – The time when Impala reserved the maximum amount of memory for queries.
Click the drop-down list next to the date and time and select View Impala Queries Running at the Time to see details about the queries.
Max Allocated – The maximum memory that was reserved by Impala for executing queries. If the percentage is high, consider increasing the number of hosts in the cluster.
Utilized at the Time – The amount of memory used by Impala for running queries at the time when maximum memory was reserved.
Click View Time Series Chart to view a chart of peak memory allocations.
Histogram of Allocated Memory at Peak Allocation Time – Distribution of memory reserved per Impala daemon for executing queries at the time Impala reserved the maximum memory. If some Impala daemons have reserved memory close to the configured limit, consider adding more physical memory to the hosts.
b) Max Utilized
Peak Usage Time – The time when Impala used the maximum amount of memory for queries.
Click the drop-down list next to the date and time and select View Impala Queries Running at the Time to see details about the queries.
Max Utilized – The maximum memory that was used by Impala for executing queries. If the percentage is high, consider increasing the number of hosts in the cluster.
Reserved at the Time – The amount of memory reserved by Impala at the time when it was using the maximum memory for executing queries.
Click View Time Series Chart to view a chart of peak memory utilization.
Histogram of Utilized Memory at Peak Usage Time – Distribution of memory used per Impala daemon for executing queries at the time Impala used the maximum memory. If some Impala daemons are using memory close to the configured limit, consider adding more physical memory to the hosts.
[1] https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/admin_cluster_util_custom.html#conce...
[2] https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/cm_metrics_impala_daemon.html
[3] https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/cm_metrics_impala_daemon_resource_po...
