This custom metric will collect data every 10 minutes and plot the delta between redo logs archived on the primary instance and logs applied on the standby instance.
METRIC DEFINITION
To create the custom metric, click on Options > Custom Resource Metrics and configure the metric similar to this:
Database Type: Oracle
Database Versions: <no limitations>
Display Name: Log Apply Drift
Description: <add your own description>
Category: <add to whatevfer category you like or create a new one>
Units: Sequence Diff
Metric Type: Single Value
Frequency: 600
Timeout: 50
SQL Statement:
select (
SELECT MAX(SEQUENCE#) LOG_ARCHIVED
FROM V$ARCHIVED_LOG
WHERE DEST_ID=1
AND ARCHIVED='YES'
) - (
SELECT MAX(SEQUENCE#) LOG_APPLIED
FROM V$ARCHIVED_LOG
WHERE DEST_ID=2
AND APPLIED='YES'
) from dual;
