The combination of interval, interval-units, duration, and duration-units define how much sampling data is maintained by the Driver Health Job. The values for these parameters directly affect how much memory the Driver Health Job requires to run.
The number of samples per driver per server is calculated as:
Number of samples = ((duration * duration units) / (polling interval * polling units)) + 1
For example, if
Number of samples = (12*60) / (1*1) + 1 = 721
If there are 4 drivers on 1 server, total number of samples = 4*1*721 = 2884.
Each sample stores data from 5 points in the publisher channel and 5 points in the subscriber channel.
A sample contains a list of IDs and counts for each point. IDs correspond to operations such as query, status, instance, add-association, and so on.
Consider the following driver cache statistics:
<subscriber> <operations> <command-results> <status>12</status> <instance>12</instance> </command-results> </operations> </subscriber>
For subscriber-command-results, the list has IDs 7,21 (for instance and status) and counts 12,12.
Each sample consumes ~700 bytes.
721 samples consume ~ 500 KB. This is the memory requirement per driver.
For 4 drivers, 2 MB is required for storing sampling data.