Hello,

I’m interested in H2 clustering feature. My use case is two databases
running on two distinct computers A & B. Note that my application is
intend to run on A or B.

My questions concerns failover management.
First of all, is there supplementary documentation about this feature
not included in H2 web-site?

At start-up, is there a way to detect automatically if a database is
not up-to-date?

If I consider the following scenario:
-       Initial state: A & B are running OK
-       A crash (B is still running, and it is transparent for application
layer)
-       B continues to be updated
-       B stops properly
When A & B are restarted, is there a way to automatically detect
databases states? (something like: A is KO, B is OK)
If only A is restarted, is there a way to detect that it is KO?

I have played with a simple code (on only one computer), and I made
this observation:
After running the above scenario, when I tried to open B with the file
protocol (“jdbc:h2:file:./nodeB/test”) => OK (db is successfully
opened)
If I do the same thing with database A, I have the following error:
Clustering error - database currently runs in cluster mode, server
list: "'localhost:9191,localhost:9192'" [90094-155]
Then, can I consider that opening a database with the file protocol is
a relevant test to check its state? I guess no, but...

Then, if I consider the following scenario:
-       Initial state: A & B are running OK
-       A crash (B is still running, and it is transparent for application
layer)
-       B continues to be updated
-       A is restarted
What are the expected operations to come back to a normal situation?
Is there an alternative to delete database A and reconstruct the
cluster? (some kind of partial resynchronization).

Finally, I guess that for automatic recovery I need to write code on
top of H2. Is there any example of such management? Experience
feedback from other projects?

Moreover, what is the performance overhead when running clustering
mode? What about robustness to network latencies?

Regards.

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