6.3.3.3 Monitoring PMEM Cache Using Exadata Metrics

Exadata metrics that are related to PMEM cache are identified in the Exadata storage server METRICCURRENT, METRICDEFINITION, and METRICHISTORY objects as having objectType=PMEMCACHE.

Note that because reads from PMEM cache are primarily performed using RDMA calls from Oracle Database, there are no Exadata metrics that tally PMEM cache I/O.

Example 6-3 Displaying PMEM Cache Metric Definitions

This example shows how to display the PMEM cache metric definitions that are available in the Oracle Exadata System Software.

CellCLI> LIST METRICDEFINITION ATTRIBUTES NAME,DESCRIPTION WHERE OBJECTTYPE = PMEMCACHE
         PC_BY_ALLOCATED         "Number of megabytes allocated in PMEM cache"

Note the following additional details:

• PC_BY_ALLOCATED represents the number of megabytes allocated in PMEM cache and tracks how many cachelines are used in the PMEM cache. If the value is close to the PMEM cache size, then the PMEM cache is fully populated.

  This metric is also available per database (DB_PC_BY_ALLOCATED), and per PDB (PDB_PC_BY_ALLOCATED).