Skip to content
Nebula Logger

LogBatchPurger

LogBatchPurger is the Apex batch job that acts on retention dates. It queries for logs whose LogRetentionDate__c is past-due and runs the configured purge action on each.

The batch does not run automatically

Section titled “The batch does not run automatically”

Nebula Logger sets LogRetentionDate__c on new Log__c records automatically. Actually purging them requires scheduling LogBatchPurger via LogBatchPurgeScheduler.

Run once from anonymous Apex:

String cronExpression = '0 0 2 * * ?'; // Every day at 2:00 AM
System.schedule('Nebula Logger - Daily Purge', cronExpression, new LogBatchPurgeScheduler());

Verify: Setup > Scheduled Jobs. You should see the job listed.

Cron expression cookbook

Section titled “Cron expression cookbook”

Salesforce cron format is Seconds Minutes Hours Day-of-Month Month Day-of-Week Year. Common patterns:

Cadence Expression
Daily at 2am 0 0 2 * * ?
Every 6 hours 0 0 */6 * * ?
Every Sunday at 3am 0 0 3 ? * SUN *
First of the month 0 0 3 1 * ?

Adjusting batch size

Section titled “Adjusting batch size”

The default batch size is fine for most orgs. For very large log volumes, tune:

Integer batchSize = 500;
System.schedule('Nebula Logger - Daily Purge', cronExpression, new LogBatchPurgeScheduler(batchSize));

LogBatchPurgeScheduler has a no-arg constructor for the default and an Integer batchSize constructor for override. Higher batch sizes reduce total execution time at the cost of longer individual transactions.

What LogBatchPurger processes

Section titled “What LogBatchPurger processes”

LogBatchPurger walks the object hierarchy from the lowest level up:

  1. LogEntryTag__c (junction records)
  2. LogEntry__c (child entries)
  3. Log__c (parent transactions)

It processes records whose parent Log__c.LogRetentionDate__c is past-due. This ordering matters because LogEntry__c records reference Log__c - deleting the parent first would fail.

Manually triggering a purge

Section titled “Manually triggering a purge”

The Logger Console home page has a logBatchPurge component that triggers the batch on demand and reports counts. Useful for:

  • Verifying the job runs correctly after a fresh install.
  • Cleaning up test-generated logs immediately.
  • Investigating retention behavior without waiting for the scheduled run.

What happens to each record

Section titled “What happens to each record”

The purge action determines the fate of each aged-out record. See Purge actions for the options - by default, records are hard-deleted (no Recycle Bin).

Where next

Section titled “Where next”