(DI-2211) Collector for HANA Save Point performance
The technical name of the Collector for HANA Save Point performance is /DVD/MON_HDB_CL_COL_SP.
This collector collects information about Save Point performance according to the view M_SAVEPOINTS. During a save point, the database system writes data that has changed since the last save point from the data cache (working memory) to the data area (permanent storage). The data written during a save point always represents a consistent state of the database. During a save point, the database system does not overwrite the pages written to the data area at the previous save point, but instead writes the changed data to free positions. This is because the database system requires this information from the previous save point for a restart to check if there is a system failure during the new save point. Only after the database system has successfully completed the new save point, does it release the pages of the old save point in the data area for overwriting. To perform a save point write operation, SAP HANA needs to take a global database lock. This period is called the critical phase of a save point.
Default KPIs delivered with this collector
The following default KPIs are delivered with this collector:
KPI name | Description | Unit | Collected for | Server specification |
|---|---|---|---|---|
HDB_SP_COUNT | Number of save points | Count | System | Any server |
HDB_SP_LAST | Time since the last save point | S | System | Any server |
HDB_SP_MAXRUN | Max. duration of a save point | S | System | Any server |
HDB_SP_MAXRUN_C | Max. critical phase duration of a save point | S | System | Any server |
HDB_SP_SPEED | Save point speed | MB/s | System | Any server |
Detail Table:
The collector provides a detail table for HANA Savepoint Critical Time. The technical name of the detail table is /DVD/MON_HDB_S_SP_CRIT.
Its shows a histogram of critical HANA save point time grouped by time-based on how long was their critical time. It has the following fields:
Technical Name | Short Description | Description |
|---|---|---|
TIME | HANA Savepoint Time | Time of aggregation in format ‘YYYY-MM-DD HH:MM’ |
LESS1S | HANA Critical Savepoint Less than 1 second | Number of savepoints that had critical time less than 1 second |
LESS2S | HANA Critical Savepoint Less than 2 seconds | Number of savepoints that had critical time less than 2 seconds |
LESS3S | HANA Critical Savepoint Less than 3 seconds | Number of savepoints that had critical time less than 3 seconds |
LESS4S | HANA Critical Savepoint Less than 4 seconds | Number of savepoints that had critical time less than 4 seconds |
LESS5S | HANA Critical Savepoint Less than 5 seconds | Number of savepoints that had critical time less than 5 seconds |
LESS10S | HANA Critical Savepoint Less than 10 seconds | Number of savepoints that had critical time less than 10 seconds |
LESS20S | HANA Critical Savepoint Less than 20 seconds | Number of savepoints that had critical time less than 20 seconds |
LESS40S | HANA Critical Savepoint Less than 40 seconds | Number of savepoints that had critical time less than 40 seconds |
LESS60S | HANA Critical Savepoint Less than 60 seconds | Number of savepoints that had critical time less than 60 seconds |
MORE60S | HANA Critical Savepoint More than 60 seconds | Number of savepoints that had critical time of more than 60 seconds |
TOTAL | HANA Total number of savepoints with critical time | Total number of save points |