Arbiter.Migrations

Migration options and the desired state reconciled after a schema's tracked migrations run.

Notify triggers on, event streaming off, unlogged rate-limit buckets, no lock timeout.

Migrate every queue in a registry into one schema. The schema itself is created first, outside migration tracking. Names that fail validateRegistryNames return MigrationError before the connection opens.

type AppRegistry =
  '[ Queue "email_jobs" EmailPayload
   , Queue "order_jobs" OrderPayload
   ]

main :: IO ()
main = do
  result <- runMigrationsForRegistry
              (Proxy @AppRegistry)
              "host=localhost dbname=mydb"
              "arbiter"
              defaultMigrationConfig
  print result

Migrate several tables in one schema. On success, seed the policies, then reconcile durability and triggers on the same connection. The table list must be the schema's whole queue set. An omitted queue loses its notify and event-streaming objects. Names that fail validateRegistryNames return MigrationError before the connection opens.

One queue's tracked migrations, each under its own version identifier. The optional notify and event-streaming objects are reconciled after the migrations run.

The schema-level migrations, run once per schema. The optional notification and event-streaming objects are reconciled after the migrations run.

Admission policy rows to seed after a successful migration.

Seeds for a deployment with no admission policies.

Which admission trigger kinds a table's payload declares. Trigger migrations are install-only. A kind removed from a payload keeps its triggers.

Install every admission trigger kind.

Reject an empty or over-long schema name, and queue names that are empty, exceed maxQueueNameBytes, generate a schema-wide arbiter table, or generate the same object or channel name as another queue.

The longest queue name whose generated identifiers stay distinct after PostgreSQL truncates them to maxIdentifierBytes.

Rate-limit policy prefixes declared with more than one parameter set.

A queue's table name, payload type, and handler result type. A type data constructor. It takes no promotion tick.

A queue whose handlers store no result. A module with its own Queue type needs import Arbiter.Core hiding (Queue) or a qualified import.

MigrationCommand determines the action of the runMigration script.

A sum-type denoting the result of a migration.

Whether the rate-limit bucket table is WAL-logged. Set by the migration config.

A token-bucket policy. Burst policyMax, refilling continuously at policyRefill per policyInterval. A policyRefill of 0 is a manually-refilled bucket. Fields are non-negative and the interval is positive. The migration rejects other values.

A concurrency policy. At most cpLimit jobs are in flight per key under cpPrefix. The default is seeded. An operator override on the policy takes precedence.

PostgreSQL schema name, e.g. "arbiter".

Unqualified table name within a schema, e.g. "email_jobs".