CODEWITHSUNDEEP
google-app-engine
Vik
Vik

Reputation: 9319

Rollback the changes in failure situation

I have a situation where we update an entity data and then based on certain type of updates we may update another entity as well.

There are situations when the updation in the second entry may fail for some reasons and throw exceptions.

The question is how to handle this situation as we would like to rollback the changes done in the first entity.

We cannot defer the update to the first entry until the second entry update.

In the current situation if that happens then

as soon as the code reach the below block then it will commit the first entry changes even there are failures in 2nd entity update. so how to rollback? I think not closing the persistentManager if 2nd entity update is failed is not the right option.

finally {
            try {
                if (pm != null && pm.isClosed() == false )
                    pm.close();
            } catch (Exception e) {
                log.severe("Exception in finally of execute of updateDonor");
                log.severe("Exception class is :" + e.getClass().getName());
                log.severe("Exception is :" + e.getMessage());
                throw new Exception(e.getMessage()
                        + "Unable to close persistence manager");
            }
            log.info("end of updateDonor");
        }

Upvotes: 0

Views: 135

Answers (1)

Amy U.
Amy U.

Reputation: 2237

I'm not sure I fully understand your situation, but would cross-group (XG) transactions, which allow a transaction to be applied to entities from more than one entity group, be what you are looking for? Search for 'cross-group transactions on this page as well. With an XG transaction, either all changes to the entities encompassed by the transaction go through, or none do.

Upvotes: 1

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