Availability

Database availability assists you to conveniently know the availability status of your database in both real-time and historical modes.

Repository table

This metric that provides information on database availability is gathered from the repository table <SCHEMA>.DBSTATUS.

Source

The DB_STATUS information is gathered from IBM Db2® table function MON_GET_DATABASE with parameter -2, for information from all active database members.

Columns

Table 1. DBSTATUS
Column Name Type Description
SNAPSHOT_ID BIGINT Unique ID of the database status row that was inserted.
SNAPSHOT_TIME TIMESTAMP The timestamp when the database status was collected.
DATABASE_NAME VARCHAR(255) Name of the database.
DB_STATUS VARCHAR(32) The status of the database.
collectFrequencyInMin BIGINT Monitoring data collection interval in minutes.

Metric calculation

A row is inserted in the repository table DBSTATUS every 5 minutes (by default). The DB_STATUS column indicates the status in each snapshot. The status can be one of the following:

  • ACTIVE
  • QUIESCE_PEND
  • QUIESCED
  • ROLLFW
  • UNREACHABLE

UNREACHABLE status is returned based on if the connection can be established to the database.

The availability percentage is calculated from the DBSTATUS repository table based on the start and end timestamp provided. The row that is returned from the table is the status of database availability.

The availability percentage is calculated as 
(1 – total database unavailable time) * 100
where the total database unavailable time is the aggregation of collectFrequencyInMin column from DBSTATUS table for all the rows with DB_STATUS as not ACTIVE.
It is calculated as 
total database unavailable time = (aggregation of collectFrequencyInMin * 60000)/<end_timestamp> - <start_timestamp>
where <end_timestamp> - <start_timestamp> is the length of the collection interval in milliseconds. The collectFrequencyInMin is multiplied by 60000 to scale it to milliseconds.
Note: Database availability metric data relies on the availability status of the repository database. Therefore, if you have a connection to the repository database for IBM® Db2 Intelligence Center, the database availability metric cannot be relied upon.