Debug WorkManager

If you notice that your workers run too often or not at all, here are some debugging steps that can help you discover what is happening.

Enable logging

To determine why your workers aren't running properly, it can be very useful to look at verbose WorkManager logs. To enable logging, use custom initialization.

First, disable the default WorkManagerInitializer in your AndroidManifest.xml file by creating a new WorkManager provider with the manifest-merge rule remove applied:

<provider
    android:name="androidx.work.impl.WorkManagerInitializer"
    android:authorities="${applicationId}.workmanager-init"
    tools:node="remove"/>

Now that the default WorkManager initializer is disabled, you can use on-demand initialization. To do so, the android.app.Application class needs to provide an implementation for androidx.work.Configuration.Provider:

Kotlin

class MyApplication() : Application(), Configuration.Provider {
    override fun getWorkManagerConfiguration() =
        Configuration.Builder()
            .setMinimumLoggingLevel(android.util.Log.DEBUG)
            .build()
}

Java

public class MyApplication extends Application implements Configuration.Provider {
    @NonNull
    @Override
    public Configuration getWorkManagerConfiguration() {
        return new Configuration.Builder()
                .setMinimumLoggingLevel(android.util.Log.DEBUG)
                .build();
    }
}

When you define a custom WorkManager configuration, your WorkManager is initialized when you call WorkManager.getInstance(Context) rather than automatically at application startup. See Custom WorkManager Configuration and Initialization for more information, including support for versions of WorkManager before 2.1.0.

With DEBUG logging enabled, you see a lot more logs with the log-tag prefix WM-.

Use adb shell dumpsys jobscheduler

You can use adb to get more information about job scheduling on Android 6.0 (API level 23) or higher. If you are new to adb, see Command-line tools for more details.

Once you have adb installed, run the following command to look at the list of jobs that are attributed to your package:

adb shell dumpsys jobscheduler

The output looks something like this:

JOB #u0a172/4: 6412553 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
  u0a172 tag=*job*/com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
  Source: uid=u0a172 user=0 pkg=com.google.android.youtube
  JobInfo:
    Service: com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
    Requires: charging=false batteryNotLow=false deviceIdle=false
    Extras: mParcelledData.dataSize=180
    Network type: NetworkRequest [ NONE id=0, [ Capabilities: NOT_METERED&INTERNET&NOT_RESTRICTED&TRUSTED&VALIDATED Uid: 10172] ]
    Minimum latency: +1h29m59s687ms
    Backoff: policy=1 initial=+30s0ms
    Has early constraint
  Required constraints: TIMING_DELAY CONNECTIVITY [0x90000000]
  Satisfied constraints: DEVICE_NOT_DOZING BACKGROUND_NOT_RESTRICTED WITHIN_QUOTA [0x3400000]
  Unsatisfied constraints: TIMING_DELAY CONNECTIVITY [0x90000000]
  Tracking: CONNECTIVITY TIME QUOTA
  Implicit constraints:
    readyNotDozing: true
    readyNotRestrictedInBg: true
  Standby bucket: RARE
  Base heartbeat: 0
  Enqueue time: -51m29s853ms
  Run time: earliest=+38m29s834ms, latest=none, original latest=none
  Last run heartbeat: 0
  Ready: false (job=false user=true !pending=true !active=true !backingup=true comp=true)

When using WorkManager, the component responsible for managing worker execution is SystemJobService on API level 23 or higher. Look for instances of jobs that are attributed to your package name and androidx.work.impl.background.systemjob.SystemJobService.

For every job, the output from the command lists required, satisfied, and unsatisfied constraints. Check whether your worker’s constraints are fully satisfied.

The output also includes job history for recently executed jobs, so you can use it to check whether SystemJobService was invoked recently.

Job history:
     -1h35m26s440ms   START: #u0a107/9008 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
     -1h35m26s362ms  STOP-P: #u0a107/9008 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService app called jobFinished

Request diagnostic information from WorkManager 2.4.0+

On debug builds of your app, you can request diagnostic information from WorkManager 2.4.0 and higher using the following command:

adb shell am broadcast -a "androidx.work.diagnostics.REQUEST_DIAGNOSTICS" -p "<your_app_package_name>"

This provides information on:

Work requests that completed in the last 24 hours.
Work requests that are currently running.
Work requests that are scheduled.

Here is what it could look like (the output is visible through logcat):

adb shell am broadcast -a "androidx.work.diagnostics.REQUEST_DIAGNOSTICS" -p "androidx.work.integration.testapp"

adb logcat
...
2020-02-13 14:21:37.990 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Recently completed work:
2020-02-13 14:21:38.083 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Id  Class Name   State  Unique Name Tags
    08be261c-2def-4bd6-a716-1e4410968dc4     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    48ce04f1-8df9-450b-96ec-6eceabb9c690     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    c46f4699-c384-440c-a10e-26d56ce02963     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    ce125372-046e-484e-949f-9abb35ce62c3     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    72887ddd-8ed1-4018-b798-fac218e95e16     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    dcff3d61-320d-4996-8644-5d97944bd09c     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    acab0bf7-6087-43ad-bdb5-be0df9195acb     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    23136bcd-01dd-46eb-b910-0fe8a140c2a4     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    245f4879-c6d2-4997-8130-e4e90e1cab4c     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    17d05835-bb61-429a-ad11-fe43fc320a54     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    e95f12be-4b0c-4e64-88da-8ee07a31e42f     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    431c3ec2-4a55-469b-b50b-4072d35f1232     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    883a388f-f911-4098-9143-37bd8fbc098a     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    b904163c-6822-4299-8d5a-78df49b7e53d     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    453fd7b9-2b16-45b9-abc5-3d2ce7b6a4ba     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
2020-02-13 14:21:38.083 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Running work:
2020-02-13 14:21:38.089 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Id  Class Name   State  Unique Name Tags
    b87c8a4f-4ac6-4e25-ba3e-4cea53ce468a     androidx.work.impl.workers.DiagnosticsWorker    RUNNING    null    androidx.work.impl.workers.DiagnosticsWorker
...