Is it possible rollback Azure storage table transactions so that I do not lose data?

Question

I am fairly new to Azure cloud development.

I have a function app coded in C# that:

1. Gets a record from a storage table
2. Deletes that record
3. Updates fields on that record (including the partition key)
4. inserts the new record into the storage table

I am experiencing data loss, when an exception is thrown, on the insert portion.

I am wondering how, if step 4 throws an exception, I can then rollback step 2. If that is not possible how would I prevent the data loss, as I'm unable to use the built in Table Operations that would replace the entity because I am changing the partition key?

I understand that the hard part in all of this to be the partition key update, as I know the system was designed so that each transaction or operation is operating on records with the same partition key.

I have looked through the Table Service REST API and looked at all the Table Operations I thought could be helpful: Insert Entity Update Entity Merge Entity Insert or Update Entity Insert or Replace Entity

Answer 1

You can't do transactions due to partition key. So you'll have to look at a solution outside of the table storage.

What you could do is create the record before deleting it. That way you're assured that you won't lose any data (as long as you make sure the request to create a record succeeded).

You could take it one step further by making it an async process. Having a storage queue or service bus queue up your message containing the information of the request and having a function app (or anything else) handle the requests. That way you can assure the request remains retryable in case any transient errors occur over a larger timespan.