Task Queue Names

The Temporal Service maintains a set of Task Queues, which Workers poll to see what work needs to be done. Each Task Queue is identified by a name, which is provided to the Temporal Service when launching a Workflow Execution. In this example, the value is included in request to start the Workflow.

Python

Excerpt of code used to start the Workflow in Python

client = await Client.connect("localhost:7233", namespace="default")

# Execute a workflow
result = await client.execute_workflow(
    GreetingWorkflow.run,
    name,
    id="my-workflow",
    task_queue="my-task-queue-name",
)

Excerpt of code used to configure the Worker in Python

worker = Worker(
    client,
    task_queue="my-task-queue-name",
    workflows=[GreetingWorkflow],
    activities=[activities.say_hello],
)

Go

Excerpt of code used to start the Workflow in Go

options := client.StartWorkflowOptions{
    ID:        "my-workflow",
    TaskQueue: "my-task-queue-name",
}

run, err := c.ExecuteWorkflow(ctx, options, ProcessOrderWorkflow, input)

Excerpt of code used to configure the Worker in Go

w := worker.New(c, "my-task-queue-name", worker.Options{})

Java

Excerpt of code used to start the Workflow in Java

WorkflowOptions options = WorkflowOptions.newBuilder()
        .setWorkflowId("my-workflow")
        .setTaskQueue("my-task-queue-name")
        .build();

MyWorkflow workflow = client.newWorkflowStub(MyWorkflow.class, options);

Excerpt of code used to configure the Worker in Java

Worker worker = factory.newWorker("my-task-queue-name");

Typescript

Excerpt of code used to start the Workflow in TypeScript

await client.workflow.start(OrderProcessingWorkflow, {
  args: [order],
  taskQueue: "my-task-queue",
  workflowId: `workflow-order-${order.id},`,
})

Excerpt of code used to configure the Worker in TypeScript

const worker = await Worker.create({
  taskQueue: "my-task-queue",
  connection,
  workflowsPath: require.resolve('./workflows'),
  activities,
});

.NET

Excerpt of code used to start the Workflow in C# and .NET

var options = new WorkflowOptions(
            id: "translation-workflow",
            taskQueue: "my-task-queue");

// Run workflow
var result = await client.ExecuteWorkflowAsync(
    (TranslationWorkflow wf) => wf.RunAsync(input),
    options);

Excerpt of code used to configure the Worker in C# and .NET

using var worker = new TemporalWorker(
    client,
    new TemporalWorkerOptions("my-task-queue")
    .AddAllActivities(activities)
    .AddWorkflow<TestWorkflow>());

Since Task Queues are created dynamically when they are first used, a mismatch between these two values does not result in an error. Instead, it will result in the creation of two different Task Queues. Consequently, the Worker will not receive any tasks from the Temporal Service and the Workflow Execution will not progress. Therefore, we recommend that you define the Task Queue name in a constant that is referenced by the Client and Worker if possible, as this will ensure that they always use the same value.

Python

Excerpt of code used to define a constant with the Task Queue name in Python (in a shared.py file)

TASK_QUEUE_NAME = "my-task-queue-name"

Excerpt of code used to start the Workflow, referencing the constant defined with the Task Queue name in Python

from shared import TASK_QUEUE_NAME

...

client = await Client.connect("localhost:7233", namespace="default")

# Execute a workflow
result = await client.execute_workflow(
    GreetingWorkflow.run,
    name,
    id="my-workflow",
    task_queue=TASK_QUEUE_NAME,
)

Excerpt of code used to configure the Worker, referencing the constant defined with the Task Queue name in Python

worker = Worker(
    client,
    task_queue=TASK_QUEUE_NAME,
    workflows=[GreetingWorkflow],
    activities=[activities.say_hello],
)

Go

Excerpt of code used to define a constant with the Task Queue name in Go

package app 

const TaskQueueName = "my-taskqueue-name"

Excerpt of code used to start the Workflow, referencing the constant defined with the Task Queue name in Go

options := client.StartWorkflowOptions{
    ID:        "my-workflow",
    TaskQueue: app.TaskQueueName,
}

run, err := c.ExecuteWorkflow(ctx, options, ProcessOrderWorkflow, input)

Excerpt of code used to configure the Worker, referencing the constant defined with the Task Queue name in Go

w := worker.New(c, app.TaskQueueName, worker.Options{})

Java

Excerpt of code used to define a constant with the Task Queue name in Java

package app;

public class Constants {

  public static final String taskQueueName = "my-task-queue-name";

}

Excerpt of code used to start the Workflow, referencing the constant defined with the Task Queue name in Java

WorkflowOptions options = WorkflowOptions.newBuilder()
        .setWorkflowId("my-workflow")
        .setTaskQueue(Constants.taskQueueName)
        .build();

MyWorkflow workflow = client.newWorkflowStub(MyWorkflow.class, options);

Excerpt of code used to configure the Worker, referencing the constant defined with the Task Queue name in Java

Worker worker = factory.newWorker(Constants.taskQueueName);

Typescript

Excerpt of code used to define a constant with the Task Queue name in TypeScript

const TASK_QUEUE_NAME = "my-taskqueue-name"

Excerpt of code used to start the Workflow, referencing the constant defined with the Task Queue name in TypeScript

import { TASK_QUEUE_NAME } from './shared';

// additional code would follow

await client.workflow.start(OrderProcessingWorkflow, {
  args: [order],
  taskQueue: TASK_QUEUE_NAME,
  workflowId: `workflow-order-${order.id},`,
})

Excerpt of code used to configure the Worker, referencing the constant defined with the Task Queue name in TypeScript

import { TASK_QUEUE_NAME } from './shared';

// additional code would follow

const worker = await Worker.create({
  taskQueue: TASK_QUEUE_NAME,
  connection,
  workflowsPath: require.resolve('./workflows'),
  activities,
});

.NET

Excerpt of code used to define a constant with the Task Queue name in C# and .NET

public static class WorkflowConstants
{
    public const string TaskQueueName = "translation-tasks";
}

Excerpt of code used to start the Workflow, referencing the constant defined with the Task Queue name in C# and .NET

var options = new WorkflowOptions(
            id: "translation-workflow",
            taskQueue: WorkflowConstants.TaskQueueName);

// Run workflow
var result = await client.ExecuteWorkflowAsync(
    (TranslationWorkflow wf) => wf.RunAsync(input),
    options);

Excerpt of code used to configure the Worker, referencing the constant defined with the Task Queue name in C# and .NET

using var worker = new TemporalWorker(
    client,
    new TemporalWorkerOptions(WorkflowConstants.TaskQueueName)
    .AddAllActivities(activities)
    .AddWorkflow<TranslationWorkflow>());

However, it’s not always possible to do this, such as when the Client used to start the Workflow is running on another system or is implemented in a different programming language.

Running Multiple Worker Processes

Finally, we recommend running at least two Worker Processes for each Task Queue in a production application, each running on a separate host.

This eliminates the Worker as a single point of failure, because if there are two Worker Processes and one of them crashes, the remaining Worker will recover any executions that were in progress and will continue to handle new ones, too. Running additional Worker Processes will further increase the scalability and availability of your application.