Detect late events

This guide reports the events that arrived after the run that bills a month read it. Nothing is changed by it: booking those events is what correct a finalized period does. Why a month takes late events at all is in billing period lifecycle and corrections.

Before you start

• Both databases reachable from the machine you run the CLI on: the engine's own and the Reporting API's, the second one through a login role that is a member of tally_engine_reader.
• A finalized run of the month. The report is held against the latest finalized run of the period and the instant that run read the events at.
• tally-engine at the version the deployment runs, with its subcommands on the engine CLI page.
• The engine settings page, which names the two variables this guide sets.

Ask the month what arrived late

1. Export both databases. detect-late reads the run and its snapshot from the engine database and the events from the reporting one:

   export TALLY_ENGINE_DB_URL='postgres://tally:password@db.internal:5432/tally_engine?sslmode=require'
   export TALLY_ENGINE_REPORTING_DB_URL='postgres://tally_engine:password@db.internal:5432/tally_reporting?sslmode=require'

2. Name the month. The first line states the run and the instant its events are held against, so what the report compares is said before it:

   tally-engine detect-late --period 2026-07

   run <run id> read 2026-07 at <snapshot>
   no events arrived later

3. A month that did take late events lists one resource per line, then the command that books them:

   tally-engine detect-late --period 2026-07

   run <run id> read 2026-07 at <snapshot>
   os-prod-eu1/openstack/instance/<resource id>: <n> late events, last received <instant>
   book them with tally-engine correct --period 2026-07

   The resources past the report's cap are counted on one further line, and <n> more resources with late events.

Check the result

1. Read which of the two answers came back. no events arrived later means every event the period bills was already in the reporting database when the run read it, and the finalized numbers stand.

2. A resource line names the cloud, the platform, the resource type and the resource id, how many of its events arrived after the snapshot, and when the last of them did. The month's numbers do not yet account for them: correct is what books them into credit notes.

3. A period with no finalized run is refused, and the error names the two commands that produce one:

   2026-07 has no finalized run, and late events are late against one: tally-engine run --period 2026-07 and tally-engine finalize produce it