Trax data model

Source Models/, Migrations/, Migrations/

The Postgres and Sqlite data providers create these tables in the trax schema from their core migration set. InMemory holds the same entities without tables. Each is read through a DbSet on IDataContext.

Tables

Table	Entity	Holds
`metadata`	`Metadata`	One row per run: state, timing, input and output, errors, host. Fields on Metadata.
`log`	`Log`	Log lines stored by `AddDataContextLogging`, each naming the run that wrote it. Columns on Debug across processes with the log table.
`manifest`	`Manifest`	A schedule definition: the train, its input, cron or interval, retry policy, timeout
`manifest_group`	`ManifestGroup`	Per-group dispatch controls (`MaxActiveJobs`, `Priority`, `IsEnabled`)
`work_queue`	`WorkQueue`	Entries between scheduling and dispatch
`dead_letter`	`DeadLetter`	Manifests whose runs exceeded their retry limit
`background_job`	`BackgroundJob`	The PostgreSQL job submission queue, with a visibility timeout
`scheduler_config`	`SchedulerConfig`	The scheduler settings the dashboard can edit at runtime
`decision`	`RecordedDecision`	Each decision a run made; columns on Decision records
`junction_run`	`JunctionRun`	Each step of a run stored by junction events
`checkpoint`	`Checkpoint`	One row per run and declared node a run can resume from
`effect_claim`	`EffectClaim`	An idempotency claim for an exactly-once side effect, with a lease and fence token
`runner_nonce`	`RunnerNonce`	Nonces a runner accepted on signed requests, so instances sharing the database accept a request once
`snapshot_draft`	`SnapshotDraft`	State machine instance drafts, used by `Trax.StateMachine.Persistence`
`snapshot_transition`	`SnapshotTransition`	Each state-machine instance's history, one row per snapshot write, deleted with the instance
`persisted_operation`	`PersistedOperation`	Stored GraphQL operations served by id
`persisted_operation_history`	`PersistedOperationHistory`	One row per change to a persisted operation

The Postgres provider records its applied migrations in trax.migrations.

Entity members

Members of the entities above that the column lists on other pages do not cover.

Member	Description
`BackgroundJob.FetchedAt`	When a worker claimed the job; null while it is available. A value older than the visibility timeout makes it claimable again
`DeadLetter.RetryMetadata`	The run created for a retry of the dead letter, once one is linked
`DeadLetter.MarkRetried(retryMetadataId)`	Sets the status to `Retried`, the resolution time, and the retry run's id
`DeadLetter.LinkRetryMetadata(retryMetadataId)`	Links the retry run's id after a requeued entry is dispatched
`EffectClaim.LeaseExpiresAt`	When an in-flight claim's lease ends; a claim with no receipt past it can be reclaimed
`Exclusion.IsExcluded(utcNow)`	Whether a UTC time falls inside the exclusion window
`Manifest.DependsOnManifest`	The parent manifest of a dependent manifest
`Manifest.FailureWindowSeconds`	How far back, in seconds, a failed run counts toward `MaxRetries`; null uses the scheduler's window. Zero and negative values are refused
`Manifest.PropertyType`	The type `PropertyTypeName` names, among loaded types implementing `IManifestProperties`; `Unit` when there is none. Not mapped
`Manifest.NameType`	The train type `Name` names, among loaded types. Not mapped
`Manifest.ResolvePropertyType(registeredInputTypes)`	The type `PropertyTypeName` names, chosen only from the given input types
`Manifest.GetPropertiesUntyped()`	`Properties` deserialized as `PropertyType`
`Manifest.SetProperties(properties)`	Serializes the input into `Properties` and records its type's full name in `PropertyTypeName`
`Manifest.SetExclusions(exclusions)`	Stores the exclusion windows as JSON
`SchedulerConfig.SingletonId`	`1`, the id of the table's one row
`SchedulerConfig.TryGetOverride<T>(name, out value)`	Reads a setting a save named from `Overrides`; false when it names none
`SchedulerConfig.SetOverride<T>(name, value)`	Records a setting as named by a save
`SchedulerConfig.RemoveOverride(name)`	Drops a setting from `Overrides`, so each host's code value applies again
`SchedulerConfig.OverriddenSettings`	The setting names `Overrides` holds
`SnapshotDraft.ConcurrencyToken`	A new `Guid` on every write, mapped as the row's concurrency token
`WorkQueue.MinPriority`, `WorkQueue.MaxPriority`	`0` and `31`, the range a work queue entry's priority is clamped to

Infrastructure types

Type	Description
`CreateManifest`	The values `Manifest.Create` takes, `FailureWindowSeconds` (at least 1 when set) among them
`CreateDeadLetter`	The values `DeadLetter.Create` takes; `RetryCount` is stored as `RetryCountAtDeadLetter`
`CreateBackgroundJob`	The values `BackgroundJob.Create` takes
`CreateJunctionMetadata`	The per-junction values `JunctionMetadata.Create` combines with the run's metadata
`CreateLog`	One `ILogger` call, as `Log.Create` takes it for `AddDataContextLogging`
`UtcValueConverter`	In `Trax.Effect.Data`: marks every `DateTime` read from the database as UTC, applied to every `DateTime` property by each provider

Relationships

MANIFEST_GROUP (1:N) -> MANIFEST (1:N) -> METADATA (1:N) -> LOG
                           |                 |  (1:N) -> DECISION
                           | 1:N             |  (1:N) -> JUNCTION_RUN
                           v                 |  self-ref (ParentId)
                      DEAD_LETTER

A run's decision and junction_run rows are deleted with its metadata row by a cascading foreign key. JunctionMetadata, which a junction carries while it runs, is not stored in any table.

SDK Reference

IDataContext | UsePostgres | UseSqlite