Could not open database environment(error code 11)

[15915763299]

How could I fix this crash? When I build many of BoxStore, about 60 or more, it always crash

Caused by: io.objectbox.exception.DbException: Could not open database environment; please check options and file system (11: Try again) (error code 11)
at io.objectbox.BoxStore.nativeCreateWithFlatOptions(Native Method)
at io.objectbox.BoxStore.(BoxStore.java:264)
at io.objectbox.BoxStoreBuilder.build(BoxStoreBuilder.java:498)

[greenrobot]

You are opening BoxStore all at the same time or one at a time? Either way, that's not a typical usage pattern. What are you trying to achieve? I guess this is Android?

[15915763299]

You are opening BoxStore all at the same time or one at a time? Either way, that's not a typical usage pattern. What are you trying to achieve? I guess this is Android?

Yes, it's android.
I want to split table for faster query, because one user may have huge data of messages ( Our app is chat app ).
But ObjectBox can't split table, so i split database.
I put messages in 50 databases, I use multi-thread to create them, but I also use "lock" wrap the create logic.

[15915763299]

Here is stack info:
io.objectbox.BoxStore.nativeCreateWithFlatOptions(Native Method)
io.objectbox.BoxStore.(BoxStore.java:17)
l.b.d.b(BoxStoreBuilder.java:5)

There are 4 thread with name of "ObjectBox"，here is their names

ObjectBox-86-Thread-1(10430)

ObjectBox-29-Thread-46(10539)

ObjectBox-44-Thread-3(10545)

ObjectBox-49-Thread-4(10549)

And they have same stack info:
java.lang.Object.wait(Native Method)
java.lang.Thread.parkFor$(Thread.java:2127)
sun.misc.Unsafe.park(Unsafe.java:325)
java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:201)
java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:432)
java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:333)
java.util.concurrent.SynchronousQueue.poll(SynchronousQueue.java:908)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1057)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1118)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
java.lang.Thread.run(Thread.java:761)

[greenrobot]

It would not be surprising if you run into some Android system limits with that many DBs. I would suggest to try alternative solutions.

I want to split table for faster query

Can you tell us about the query? Does is use indexed properties?

PS.: the stack trace shows an idle thread waiting for work.

[15915763299]

It would not be surprising if you run into some Android system limits with that many DBs. I would suggest to try alternative solutions.

I want to split table for faster query

Can you tell us about the query? Does is use indexed properties?

PS.: the stack trace shows an idle thread waiting for work.

Yes, there are two properties use "@index". The query just like this:

fun conversation(conversationKey: String) = objectBox.boxFor(ConversationEntity::class)
.query()
.equal(ConversationEntity_.conversationKey, conversationKey)
.build()
.findFirst()

[greenrobot]

.equal(ConversationEntity_.conversationKey, conversationKey)

If you check the docs for string equality condition, you will see a note on case. If it's possible for your use case, use this instead: equal(prop, "example", StringOrder.CASE_SENSITIVE). The default without StringOrder.CASE_SENSITIVE cannot use the index (default will be changed in V3).