Configure custom status events to describe runnables

This document explains how to configure custom status events, which describe a job's runnables, when you create and run a Batch job. To learn about status events, see View a job's history through status events.

Custom status events let you provide additional details in a task's history about the progress of its runnables, which can help make a job easier to analyze and troubleshoot. For example, you can configure custom status events that describe when a runnable starts, a runnable ends, a barrier runnable is reached, or an important event happens during the progression of your code.

Before you begin

  1. If you haven't used Batch before, review Get started with Batch and enable Batch by completing the prerequisites for projects and users.
  2. To get the permissions that you need to create a job, ask your administrator to grant you the following IAM roles:

    For more information about granting roles, see Manage access to projects, folders, and organizations.

    You might also be able to get the required permissions through custom roles or other predefined roles.

Configure custom status events

Configure custom status events by using one or more of following options when you are creating a job:

  • Describe a runnable's state by defining its display name. You can do this when you create a job using the gcloud CLI or Batch API.

  • Indicate important runtime events by writing a structured task log with the batch/custom/event field for each event. You can do this when using any method to create a job as part of the definitions of script and container runnables.

Describe a runnable's state

You can configure custom status events that describe a runnable's state by defining a runnable's display name (displayName field). The resulting custom status events vary slightly for different types of runnables:

  • If you define a display name for a container runnable or script runnable, then Batch automatically adds two types of custom status events. The first custom status event indicates whenever a task starts this runnable. The second custom status event indicates whenever a tasks finishes this runnable and the corresponding exit code.

  • If you define a display name for a barrier runnable, then Batch automatically adds a custom status event that indicates whenever a task reaches this barrier.

To create and run a job with custom status events that describes a runnable's state, define the displayName field for one or more runnables using the gcloud CLI, Batch API or library.

gcloud

Use the Google Cloud CLI to create a job that includes the displayName field in one or more runnables definitions in the JSON file:

...
"runnables": [
  {
    "displayName":DISPLAY_NAME,
    ...
  }
]
...

For example, a job with custom status events that describes each runnable's state can have a JSON configuration file similar to the following:

{
  "taskGroups": [
    {
      "taskSpec": {
        "runnables": [
          {
            "displayName":"DISPLAY_NAME1",
            "script": {
              "text": "echo Hello world from script 1 for task ${BATCH_TASK_INDEX}"
            }
          },
          {
            "displayName":"DISPLAY_NAME2",
            "barrier": {}
          },
          {
            "displayName":"DISPLAY_NAME3",
            "script": {
              "text": "echo Hello world from script 2 for task ${BATCH_TASK_INDEX}"
            }
          }
        ]
      },
      "taskCount": 3
    }
  ],
  "logsPolicy": {
    "destination": "CLOUD_LOGGING"
  }
}

Replace DISPLAY_NAME1, DISPLAY_NAME2, and DISPLAY_NAME3 with the name of the runnable, which must be unique within the job—for example, script 1, barrier 1, and script 2.

API

Use the REST API to create a job that includes the displayName field in one or more runnables definitions in the JSON file:

...
"runnables": [
  {
    "displayName":DISPLAY_NAME,
    ...
  }
]
...

For example, a job with custom status events that describes each runnable's state can have a JSON configuration file similar to the following:

{
  "taskGroups": [
    {
      "taskSpec": {
        "runnables": [
          {
            "displayName":"DISPLAY_NAME1",
            "script": {
              "text": "echo Hello world from script 1 for task ${BATCH_TASK_INDEX}"
            }
          },
          {
            "displayName":"DISPLAY_NAME2",
            "barrier": {}
          },
          {
            "displayName":"DISPLAY_NAME3",
            "script": {
              "text": "echo Hello world from script 2 for task ${BATCH_TASK_INDEX}"
            }
          }
        ]
      },
      "taskCount": 3
    }
  ],
  "logsPolicy": {
    "destination": "CLOUD_LOGGING"
  }
}

Replace DISPLAY_NAME1, DISPLAY_NAME2, and DISPLAY_NAME3 with the name of the runnable, which must be unique within the job—for example, script 1, barrier 1, and script 2.

Go

import (
	"context"
	"fmt"
	"io"

	batch "cloud.google.com/go/batch/apiv1"
	"cloud.google.com/go/batch/apiv1/batchpb"
	durationpb "google.golang.org/protobuf/types/known/durationpb"
)

// Creates and runs a job with custom events
func createJobWithCustomEvents(w io.Writer, projectID, jobName string) (*batchpb.Job, error) {
	region := "us-central1"
	displayName1 := "script 1"
	displayName2 := "barrier 1"
	displayName3 := "script 2"

	ctx := context.Background()
	batchClient, err := batch.NewClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("batchClient error: %w", err)
	}
	defer batchClient.Close()

	runn1 := &batchpb.Runnable{
		Executable: &batchpb.Runnable_Script_{
			Script: &batchpb.Runnable_Script{
				Command: &batchpb.Runnable_Script_Text{
					Text: "echo Hello world from script 1 for task ${BATCH_TASK_INDEX}",
				},
			},
		},
		DisplayName: displayName1,
	}

	runn2 := &batchpb.Runnable{
		Executable: &batchpb.Runnable_Barrier_{
			Barrier: &batchpb.Runnable_Barrier{},
		},
		DisplayName: displayName2,
	}

	runn3 := &batchpb.Runnable{
		Executable: &batchpb.Runnable_Script_{
			Script: &batchpb.Runnable_Script{
				Command: &batchpb.Runnable_Script_Text{
					Text: "echo Hello world from script 2 for task ${BATCH_TASK_INDEX}",
				},
			},
		},
		DisplayName: displayName3,
	}

	runn4 := &batchpb.Runnable{
		Executable: &batchpb.Runnable_Script_{
			Script: &batchpb.Runnable_Script{
				Command: &batchpb.Runnable_Script_Text{
					Text: "sleep 30; echo '{\"batch/custom/event\": \"DESCRIPTION\"}'; sleep 30",
				},
			},
		},
	}

	taskSpec := &batchpb.TaskSpec{
		ComputeResource: &batchpb.ComputeResource{
			// CpuMilli is milliseconds per cpu-second. This means the task requires 2 whole CPUs.
			CpuMilli:  2000,
			MemoryMib: 16,
		},
		MaxRunDuration: &durationpb.Duration{
			Seconds: 3600,
		},
		MaxRetryCount: 2,
		Runnables:     []*batchpb.Runnable{runn1, runn2, runn3, runn4},
	}

	taskGroups := []*batchpb.TaskGroup{
		{
			TaskCount: 4,
			TaskSpec:  taskSpec,
		},
	}

	labels := map[string]string{"env": "testing", "type": "container"}

	// Policies are used to define on what kind of virtual machines the tasks will run on.
	// In this case, we tell the system to use "e2-standard-4" machine type.
	// Read more about machine types here: https://cloud.google.com/compute/docs/machine-types
	allocationPolicy := &batchpb.AllocationPolicy{
		Instances: []*batchpb.AllocationPolicy_InstancePolicyOrTemplate{{
			PolicyTemplate: &batchpb.AllocationPolicy_InstancePolicyOrTemplate_Policy{
				Policy: &batchpb.AllocationPolicy_InstancePolicy{
					MachineType: "e2-standard-4",
				},
			},
		}},
	}

	// We use Cloud Logging as it's an out of the box available option
	logsPolicy := &batchpb.LogsPolicy{
		Destination: batchpb.LogsPolicy_CLOUD_LOGGING,
	}

	job := &batchpb.Job{
		Name:             jobName,
		TaskGroups:       taskGroups,
		AllocationPolicy: allocationPolicy,
		Labels:           labels,
		LogsPolicy:       logsPolicy,
	}

	request := &batchpb.CreateJobRequest{
		Parent: fmt.Sprintf("projects/%s/locations/%s", projectID, region),
		JobId:  jobName,
		Job:    job,
	}

	created_job, err := batchClient.CreateJob(ctx, request)
	if err != nil {
		return nil, fmt.Errorf("unable to create job: %w", err)
	}

	fmt.Fprintf(w, "Job created: %v\n", created_job)
	return created_job, nil
}

Java


import com.google.cloud.batch.v1.BatchServiceClient;
import com.google.cloud.batch.v1.CreateJobRequest;
import com.google.cloud.batch.v1.Job;
import com.google.cloud.batch.v1.LogsPolicy;
import com.google.cloud.batch.v1.LogsPolicy.Destination;
import com.google.cloud.batch.v1.