Knowledge Drop
Last tested: Sep 21, 2020
To look closely at the regen cycle, you can use an explore like :
https://instance.looker.com/explore/system__activity/pdt_event_log?fields=pdt_event_log.id,pdt_event_log.created_time,pdt_event_log.action,pdt_event_log.action_data&f[pdt_event_log.connection]=&f[pdt_event_log.action]=&sorts=pdt_event_log.id+desc&limit=500&query_timezone=America%2FLos_Angeles&vis=%7B%7D&filter_config=%7B%22pdt_event_log.connection%22%3A%5B%7B%22type%22%3A%22%3D%22%2C%22values%22%3A%5B%7B%22constant%22%3A%22%22%7D%2C%7B%7D%5D%2C%22id%22%3A0%2C%22error%22%3Afalse%7D%5D%2C%22pdt_event_log.action%22%3A%5B%7B%22type%22%3A%22contains%22%2C%22values%22%3A%5B%7B%22constant%22%3A%22%22%7D%2C%7B%7D%5D%2C%22id%22%3A1%2C%22error%22%3Afalse%7D%5D%7D&dynamic_fields=%5B%5D&origin=share-expanded
, filtering on the connection where we're seeing issues.
If it seems like PDTs keep getting rebuilt at an interval that does not follow the cron specified for the connection, check to see whether the regen cycle is ending earlier than it should (regenerate end in the Action column, with regen_cancelled in the Action Data column).
If the reason for the regen cycle ending early is regen-cancelled, look more closely at SA to see what happened right before the "regenerate end" event. If there is a create sql error in the build right before the cycle is canceled, check the associated action data error message - it might be that the build is timing out on the database.
Specifically in the case where a PDT build times out, the regenerator process ends and restarts from the beginning (checks datagroups, rebuilds triggered PDTs). Once it get backs to that PDT that timed out, it will try to rebuild and if the build times out again then same thing happens all over again.
Note: If a table errors out with something else, like a syntax error, the regen process wouldn't stop early and restart. It would take until the next regen cycle for the build to be attempted again.
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