[jira] [Created] (IGNITE-12739) Optimistic serializable transactions may fail infinitely when read-through is enabled

[Anton Vinogradov (Jira)]

Alexey Goncharuk created IGNITE-12739:
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             Summary: Optimistic serializable transactions may fail infinitely when read-through is enabled
                 Key: IGNITE-12739
                 URL: https://issues.apache.org/jira/browse/IGNITE-12739
             Project: Ignite
          Issue Type: Bug
            Reporter: Alexey Goncharuk


In current design it is possible that the same key-value pair will be stored with different versions on primary and backup nodes. For example, a read-through is invoked separately on primary backup and values are stored with node local version.

With this precondition, if an optimistic serializable transaction is started from a backup node, the serializable check version is read from backup, but validated on primary node, which will fail the transaction with optimistic read/write conflict exception until the versions are overwritten to the same value (for example, via a pessimistic transaction).

While we need to additionally investigate whether we want to change the read-through logic to ensure the same value and version on all nodes, this particular scenario should be fixed by always enforcing reading from a primary node inside an optimistic serializable transaction.

The reproducer is attached. A known workaround is to disable read load balancing by setting "-DIGNITE_READ_LOAD_BALANCING=false" system property.



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