tree 85461792eb3f61fd8bd55a01bed4f1c989231964
parent 8e2a552f585f534f251ac2117fd20ccea598b174
author Olav Loite <koloite@gmail.com> 1582541365 +0100
committer Knut Olav Løite <koloite@gmail.com> 1582827553 +0000

spanner: return transaction outcome unknown

If a DEADLINE_EXCEEDED or CANCELED error occurs while a COMMIT request
is in flight, the outcome of the transaction is unknown as the request
might have been received and processed by the server. The client
library now returns a Spanner error with a
TransactionOutcomeUnknownError error wrapped when this happens. A user
application can check specifically for this condition by checking for
the presence of such an error in the error chain:

_, err := client.ReadWriteTransaction(ctx, func(ctx context.Context, tx *ReadWriteTransaction) error {
	tx.BufferWrite([]*Mutation{
		Insert("FOO", []string{"ID", "NAME"}, []interface{}{int64(1), "bar"}),
	})
	return nil
})
var outcomeUnknown *TransactionOutcomeUnknownError
if errorAs(err, &outcomeUnknown) {
	// DEADLINE_EXCEEDED or CANCELED occurred during commit.
	// The outcome of the transaction cannot be guaranteed.
	// Do custom error handling for this specific case.
}

Fixes #1781.

Change-Id: Iff5b2eb89b738d23c2a0fd1cc0418f38c736beb4
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/52370
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hengfeng Li <hengfeng@google.com>