We utilise a periodic Worker to fetch the location every 15 minutes.
As long as the phone is actively used and internet connection is available, everything goes by the books.
But when the app is in the background for too long and or even worse when it's in the flight-mode, the gaps between the fetches become as long as couple of hours.
I believe this is because the work is batched and it's up to the Android phone to decide when to run it again.
According to the documentation setExpedited() can in fact run a job under a higher urgency and prevent it from being batched.
Marks the WorkRequest as important to the user. In this case,
WorkManager provides an additional signal to the OS that this work is
important.
val workRequest = PeriodicWorkRequestBuilder<WappWorker>(15, TimeUnit.MINUTES).addTag(
TAG
).setExpedited(OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST).build()
I have implemented it this way and successfully compiled and ran it.
But it crashes at runtime:
java.lang.IllegalArgumentException: PeriodicWorkRequests cannot be
expedited
How odd. So this feature seems to be only allowed for OneTimeWorker and not for the PeriodicWorker.
What are my options? Is there any other way to mark my periodic worker jobs with a higher urgency? Thanks
Related
Assume there is a scheduled work like this:
PeriodicWorkRequestBuilder<RefreshAuthWorker>(
repeatInterval = 15L,
repeatIntervalTimeUnit = TimeUnit.MINUTES,
flexTimeInterval = 5L,
flexTimeIntervalUnit = TimeUnit.MINUTES
)
Let's say, At 10th minute, I forcely killed/stopped the app.
Then reopen the app again after 10 mins.
by this time, the existing/killed work is overdue by 5 mins.
Now, What will the WorkManager do?
1.WorkManager respects the missed overdue work and do it immediately and then schedule the next work.
(or)
2.WorkManager ignores the past overdue work and schedules the next work?
This is a very important scenario to me because, let's say I have to refresh a token every 15 mins. But if WorkManager does like said in 1st point then, by the time I reopen the app, the token is already expired 5 mins ago and the next work is going to happen in 15 mins. So, it's a total of 20 mins with an expired token.
Can somebody who knows any idea what will the WorkManager do in such scenario, please help.
You can't do such things with a WorkManager.
Everything might happen if an application is forced stop. It is a problem of the user if he decides to do so. You should not care.
Are you sure you do not mean - clear from recent?
The priority of WM is saving resources like battery and network data. Timing is not a big concern. The idea is that you need some work to be executed for sure at some point. Like you want to upload a picture to a server.
What WorkManager does is - it creates a job in the JobScheduler. The job is executed when all the constraints are satisfied:
You have implicit constraints related to battery saving. You have some amount of resources that you can use based on your Power Bucket level. Also, the device's state is important. You can't predict when these constraints will be satisfied.
Also you have explicit constraints that you set. Like Connectivity, Battery level and in your case: "a period". But is a no period at all. When you have a "period" work on a higher level in the WorkManager - actually it means - many single jobs in the Job Scheduler. And each one of these jobs has the above implicit constraints and your explicit which is called - timing delay. So you see:
You start the work
WM schedules a job in JS with respective constraints
After 15min timing delay is satisfied
No one can tell what is the status of the implicit constraints. The device might be dozing, or you might have used all of your data usage for the last 24 hours or something like this.
5 At some point when all the constraints are satisfied - the Work starts and when it is finished:
6. You have a new job with the same constraints as before. So in theory your "15min period work" might be executed in 24 hours and after that, it might execute the second time in 15 minutes.
I created a periodic weekly work manager worker to delete the files my application creates.
WorkManager workManager = WorkManager.getInstance(context);
workManager.cancelAllWorkByTag(workTag);
PeriodicWorkRequest periodicWorkRequest = new PeriodicWorkRequest.Builder(DeleteFileWorker.class, 7, TimeUnit.DAYS).addTag(workTag).build();
workManager.enqueueUniquePeriodicWork(workTag, ExistingPeriodicWorkPolicy.REPLACE, periodicWorkRequest);
Here, I'm telling the worker to run once a week or once each 7 days.
But when is it going to run? Can I control the approximate hour?
My guess is it will run the first time it can when the application starts and the second time will be at the same hour(approximately) and day as the first launch.
Can I configure it to run around 12 AM? It doesn't need to be an exact time.
You can't have strong expectations with WM. Please check here the Constraints section:
https://developer.android.com/topic/libraries/architecture/workmanager/how-to/debugging#use-alb-shell0dumpsys-jobscheduler
Also, let me point one thing - what you have "is not" a periodic Work.
What WM does is that it creates a single job in the JobScheduler and it has an extra Constrain - TIMING_DELAY. At the same time besides explicit constraints, you have implicit ones coming from the system. So for a work to be executed all the right conditions need to be in places related to battery optimizations, doze, power buckets, etc. So you can't say for sure when it will happen.
And when the work is executed successfully - WM creates a new job in the JS with TIMING_DELAY again the time you see as a period. So if you put 24 hours as a "period", but the conditions are not right for your work to be executed and it is delayed 10 hours - you will have a 34 hours span between 2 works.
Also, you know it is Android - on every device it is different. But you can improve this by asking your application to be excluded from battery optimization.
https://developer.android.com/training/monitoring-device-state/doze-standby#support_for_other_use_cases
Here more on what to expect from each device:
https://dontkillmyapp.com/
Also, have it in mind that you have a specific amount of time depending on your power bucket to run per day. I guess you are not using Network, but if you do - there is also a set amount of time to use the network. Without battery optimization disabled you might hit some of these:
https://developer.android.com/topic/performance/power/power-details
i am using Workmanager to perform an action every midnight , i am using it like that :
val duration = midNight.time - now.time
val workRequest =
OneTimeWorkRequestBuilder<ActionWorker>()
.setInitialDelay(duration, TimeUnit.MILLISECONDS)
.build()
WorkManager.getInstance(context)
.enqueueUniqueWork(
WORKER_ID,
ExistingWorkPolicy.REPLACE,
workRequest
)
and inside the ActionWorker doWork i write to the sharedpreferences, the problem is when duration is relatively short time like 2 to 5 hours ,action is performed perfectly, otherwise if the duration is set to 12 hours for example, the action is not performed .
i set duration to half an hour and i tried killing the process using
adb shell am kill "package name"
and the task is still performed well after half an hour, does anybody have an idea why it get lost when it is set to long duration ?
"not working for long durations" is not your problem. Try to debug the job scheduler. As WorkManager uses jobs underneath:
https://developer.android.com/topic/libraries/architecture/workmanager/how-to/debugging
Execute:
adb shell dumpsys jobscheduler
And check:
Unsatisfied constraints: TIMING_DELAY CONNECTIVITY [0x90000000]
If TIMING_DELAY is satisfied, and I am sure it will be - there might be other reasons why the Work is not executed. There are a lot of restrictions from Android like how many times a work can be executed per 24 hours or how much Network usage you are allowed. Check here:
https://developer.android.com/topic/performance/power/power-details
Are you also sure what you want to achieve? Why every night? Check:
https://developer.android.com/reference/androidx/work/Constraints.Builder
In general, the idea is for you to pick the conditions - idle/not idle device, Wi-Fi/no Wi-Fi, charging/not charging, low battery/not low battery, and then Android will decide when to execute. If there is something related to the server-side requirements I would get it. But otherwise, I don't.
And then you set the requirements, put a periodic job with a period of 24 hours and some flex period of 2-3 hours and you are done.
EDITED:
How to debug TIMING_DELAY problems:
check the following fields in the job info:
Minimum latency: +19m59s941ms
Enqueue time: -1m47s251ms
Run time:earliest=+18m12s690ms, latest=none, original latest=none
That is how you can see when the work was scheduled, what delay is set and when you should expect the TIMING_DELAY to be satisfied. If it is not what you expected - check again what you have set or check if you are now in the case of failing and retrying works. If it is retrying the minimum latency comes not from what you have set for a period/delay, but from the policy settings. More on this here:
https://developer.android.com/topic/libraries/architecture/workmanager/how-to/define-work#retries_backoff
Also, you should have in mind that the lifecycle of the Work is bigger than the one of the job. One Work can create and trash many jobs. You have a job for a single work. The work fails and needs to retry - a new job is scheduled. You can observe this more easily via:
Background Task Inspector
https://developer.android.com/studio/inspect/task
Here you can see the number of retries, etc.
I've found this weird behaviour of work manger (alpha-12) that it does not execute a job after it was enqueued. The code to enqueue the work is below.
fun enqueue(phoneNumber: String?,priorityId: String? = null): ListenableFuture<WorkInfo> {
return WorkManager.getInstance().run {
val work = OneTimeWorkRequestBuilder<ContentDownloaderWork>()
.addTag(TIMESTAMP)
.setInputData(workDataOf(PHONE to phoneNumber, PRIORITY_ID to priorityId))
.setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 1, TimeUnit.SECONDS)
.setConstraints(Constraints.Builder().setRequiredNetworkType(NetworkType.CONNECTED).build())
.build()
beginUniqueWork(TIMESTAMP + priorityId.orEmpty(), ExistingWorkPolicy.APPEND, work).enqueue()
getWorkInfoById(work.id)
}
}
I enqueue this work each time on app startup. And what I am doing is killing my app in the middle of the work process that is downloading files from server. It successfully restart every time I reopen my app but for limited number of times.
It seems like it has some sort of queue which gets filled up and does not allow any more jobs to be enqueued. When I check all available jobs by tag it show me that some are canceled and some succeeded but when I try to enqueue a new work it does nothing.
So is it a bug in workmanager or am I doing something wrong?
One important information that is missing in your description is the Android version that you're using in these tests.
WorkManager schedule workers using the JobScheduler API on Android Marshmallow (6.0, API Level 23) and newer, and it schedules a maximum amount of workers using this API at any time (default is 20, maximum is 50). The threshold you're seeing may be linked to this value.
Another important point, is that WorkManager keeps tracks of your workers for you so, if the application is killed while the worker is running, WorkManager automatically restart the worker. You don't need to do anything.
What is not clear to me, is what are you trying to achieve appending a new job every time at the application startup.
Last point, the backoff criteria of 1 second seems a bit aggressive to me. The current default value, looking into the source code, is 30 seconds and the maximum is 5 hours.
However, if you think that there're something wrong (or documented incorrectly) I suggest you to open a bug on WorkManager's public issuetracker.,
In my Android application the user has an option of using the application in offline mode. When the user opts to enter the offline mode, I download all the content from the server(which might take even upto 7 minutes) for offline usage. The usage of the application henceforth is dependent on the download of offline content.
I am using a service to download the offline content. But the service may not work in Android 8 if the app goes to the background. So what is the best approach to download the offline content for Android 8? Is it a foreground service or JobIntentService or a WorkManager?
Anything that is backed by JobScheduler — which includes JobIntentService and WorkManager — has a 10-minute limit. You indicate that your work may take up to 7 minutes, which makes me somewhat nervous.
In the short term, make your existing service be a foreground service, as that will keep your code working (other than any problems that Doze mode might impose).
If your 7-minute download work is really a series of smaller things that add up to 7 minutes, you might eventually migrate to WorkManager. Divide your work into smaller chunks and set up chained work with WorkManager, so you are certain to not go over the 10-minute limit for any of those chunks of work. Plus, WorkManager lets you establish constraints to say that your work should only be performed if you have an Internet connection. Right now (late August 2018), though, WorkManager is only 1.0.0-alpha07, so I would not ship a product based on WorkManager until it at least reaches a 1.0.0 final version.
The best approach would be to use WorkManager. As stated in the docs that:
WorkManager is intended for tasks that require a guarantee that the
system will run them even if the app exits, like uploading app data to
a server, or downloading data from server.
The benefits of using WorkManager over services includes handling of doze, standby, battery optimizations and constraint execution etc.
You can schedule a worker with WorkManager to download data for your app from server, and once data is available, you can go on with your offline mode.