Documentation

Overview

    Package tasks implements asynchronous invocation processing.

    Index

    Constants

    This section is empty.

    Variables

      AllTypes is a slice of all known types of tasks.

      View Source
      var ErrConflict = fmt.Errorf("the task is already leased")

        ErrConflict is returned by Lease if the task does not exist or is already leased.

        View Source
        var FinalizationTasks = tq.RegisterTaskClass(tq.TaskClass{
        	ID:            "try-finalize-inv",
        	Prototype:     &taskspb.TryFinalizeInvocation{},
        	Kind:          tq.Transactional,
        	Queue:         "finalizer",
        	RoutingPrefix: "/internal/tasks/finalizer",
        })

          FinalizationTasks describes how to route finalization tasks.

          The handler is implemented in internal/services/finalizer.

          View Source
          var PermanentFailure = errors.BoolTag{
          	Key: errors.NewTagKey("permanent failure to process invocation task"),
          }

            PermanentFailure set in an error indicates that the err is not resolvable by a retry. Such task is doomed.

            View Source
            var UseFinalizationTQ = experiments.Register("rdb-use-tq-finalization")

              UseFinalizationTQ experiment enables using server/tq for finalization tasks.

              Functions

              func Delete

              func Delete(ctx context.Context, typ Type, id string) error

                Delete deletes a task.

                func Enqueue

                func Enqueue(typ Type, taskID string, invID invocations.ID, payload interface{}, processAfter time.Time) *spanner.Mutation

                  Enqueue inserts one row to InvocationTasks.

                  func EnqueueBQExport

                  func EnqueueBQExport(invID invocations.ID, payload *pb.BigQueryExport, processAfter time.Time) *spanner.Mutation

                    EnqueueBQExport inserts one row to InvocationTasks for a bq export task.

                    func Lease

                    func Lease(ctx context.Context, typ Type, id string, duration time.Duration) (invID invocations.ID, payload []byte, err error)

                      Lease leases an invocation task. If the task does not exist or is already leased, returns ErrConflict.

                      func Peek

                      func Peek(ctx context.Context, typ Type, f func(id string) error) error

                        Peek calls f on available tasks of a given type.

                        func StartInvocationFinalization

                        func StartInvocationFinalization(ctx context.Context, id invocations.ID, updateInv bool)

                          StartInvocationFinalization changes invocation state to FINALIZING if updateInv is set, and enqueues a TryFinalizeInvocation task.

                          The caller is responsible for ensuring that the invocation is active.

                          TODO(nodir): this package is not a great place for this function, but there is no better package at the moment. Keep it here for now, but consider a new package as the code base grows.

                          Types

                          type Dispatcher

                          type Dispatcher struct {
                          	// How often to query for tasks. Defaults to 1m.
                          	QueryInterval time.Duration
                          
                          	// How long to lease a task for. Defaults to 1m.
                          	LeaseDuration time.Duration
                          
                          	// Number of tasks to process concurrently. Defaults to GOMAXPROCS.
                          	Workers int
                          }

                            Dispatcher queries for available tasks and dispatches them to goroutines.

                            func (*Dispatcher) Run

                            func (d *Dispatcher) Run(ctx context.Context, taskType Type, fn TaskFunc)

                              Run queries tasks and dispatches them to goroutines until ctx is canceled. Logs errors.

                              type TaskFunc

                              type TaskFunc func(ctx context.Context, invID invocations.ID, payload []byte) error

                                TaskFunc can execute a task. If the returned error is tagged with PermanentFailure, then the failed task is deleted.

                                type Type

                                type Type string

                                  Type is a value for InvocationTasks.TaskType column. It defines what a task does.

                                  const (
                                  	// BQExport is a type of task that exports an invocation to BigQuery.
                                  	// The task payload is binary-encoded BigQueryExport message.
                                  	BQExport Type = "bq_export"
                                  
                                  	// TryFinalizeInvocation is a type of task that tries to finalize an
                                  	// invocation. No payload.
                                  	TryFinalizeInvocation Type = "finalize"
                                  )

                                    Types of invocation tasks. Used as InvocationTasks.TaskType column value.

                                    func (Type) Key

                                    func (t Type) Key(taskID string) spanner.Key

                                      Key returns a Spanner key for the InvocationTasks row.

                                      Directories

                                      Path Synopsis