6.3.2.3 Monitoring XRMEM Cache Using Exadata Metrics

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

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

Example 6-2 Displaying XRMEM Cache Metric Definitions

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

CellCLI> LIST METRICDEFINITION ATTRIBUTES NAME,DESCRIPTION WHERE OBJECTTYPE = XRMEMCACHE
         XRM_BY_ALLOCATED         "Number of megabytes allocated in XRMEM cache"

Note the following additional details:

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

  This metric is also available per database (DB_XRM_BY_ALLOCATED), and per PDB (PDB_XRM_BY_ALLOCATED).