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su...@google.com
I am able to also reproduce issue #1 now; I've committed a change to the sample project that sets enableMultiInstanceInvalidation() on the DB and adjusts the timing a bit more. After running it for 15 minutes or so I am seeing multiple skipped updates.
My production app uses enableMultiInstanceInvalidation() as well, so this may be a significant factor.
ap...@google.com
Any thoughts on this one? I mean, it makes JournalMode.TRUNCATE largely useless, unless one has a penchant for random app misbehaviors. I'd like to keep using TRUNCATE, as it avoids certain headaches from WRITE_AHEAD_LOGGING.
ra...@google.com
li...@pinterest.com
To be clear, "batching" does not take care of the missed invalidation notifications. Updates for a table may be spaced hours apart, and in my production app about 5% of notifications are lost, meaning that the user does not see the update until the next one comes in, which may be hours later. It's a chatroom feature, where reliable, timely updates are important.
Also, not setting enableMultiInstanceInvalidation() does not fix the issue, it only changes the timing; notifications go missing regardless of whether I include one process or multiple.
su...@google.com
Hi - Sorry, we haven't had the chance to investigate this. I know this might be a lot to ask and thanks for giving us a sample app, but have you try adding a transaction in the invalidation tracker? You can check out Room's source code here:
Also what headaches are you trying to avoid from WAL mode?
li...@pinterest.com
Thanks for the pointer. I've built Room from source now as you suggested and do see that the problem goes away once I use the transactionality block in InvalidationTracker.mRefreshRunnable for all JournalModes. Don't know why that wasn't done in the first place, it certainly is a misconception to assume that TRUNCATE does not need it.
Regarding headaches from WAL mode:
- Android's SqliteDatabase runs TRUNCATE transactions effectively serializable due to grabbing exclusive locks right at the start of a transaction, so I can worry less about transactions failing, at the cost of reduced concurrency. My app isn't that heavy on DB ops, so favoring reliability over concurrency makes lots of sense. I'd actually assume that this is true for most Android apps, and that TRUNCATE would make a better default, not fancy WAL.
- WAL has certain other disadvantages, as pointed out here:
https://sqlite.org/wal.html In particular the risk of extended failure from SQLITE_BUSY is high for my app as it has DB connections from two processes (https://sqlite.org/wal.html#busy ); of particular concern is the recovery case after a crash, where one process may hold an exclusive lock for an extended period of time at startup, essentially causing the other process to error out without much recourse.
Hope this can be fixed soon in an official build; seems a trivial change.
Description
Version used: 1.0.0-beta05
Devices/Android versions reproduced on: all devices
The context of this ticket is to support initializing WorkManager a bit later after the application cold start in order to keep cold start fast. I am aware that:
1. WorkManager has this auto-initialization support through the WorkManagerInitializer provider.
2. It can be disabled and replaced by a custom provider to call WorkManager.initialize() directly or call it from Application.onCreate().
3. A number of services and receivers are registered by WorkManager and they rely on the early initialization of the WorkManager.
During testing, I realized the WorkManager.initialize() spends non-trivial time, it could be 50ms on some low end devices. So I want to avoid that delay during the cold start and have an option to initialize WorkManager a bit later. The request is to add code into the receivers and services to initialize WorkManager by themselves if WorkManager has not been initialized. This will help to cover the time from the application startup to the time that the application initialize the WorkManager manually.
Currently, a crash will happen in those receivers and services if they are triggered before the WorkManager is initialized in the application.
03-04 22:35:15.552 5784-5784/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.pinterest, PID: 5784
java.lang.RuntimeException: Unable to create service androidx.work.impl.background.systemjob.SystemJobService: java.lang.IllegalStateException: WorkManager needs to be initialized via a ContentProvider#onCreate() or an Application#onCreate().
at android.app.ActivityThread.handleCreateService(ActivityThread.java:3172)
at android.app.ActivityThread.-wrap5(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1550)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.IllegalStateException: WorkManager needs to be initialized via a ContentProvider#onCreate() or an Application#onCreate().
at androidx.work.impl.background.systemjob.SystemJobService.onCreate(SystemJobService.java:68)
at android.app.ActivityThread.handleCreateService(ActivityThread.java:3162)
at android.app.ActivityThread.-wrap5(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1550)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)