Related post on uniqueness of replayIds
Using Workbench to examine metadata for the OOTB field ReplayId on any Platform Event SObject (one that ends in __e) shows:
- bytelength: 3000
- length: 1000
- type: String
Now, evidence shows (and Platform Event documentation and related StreamingAPI documentation) this value to be an integer. Even the JSON example in the StreamingAPI shows it as a number:
{ "clientId":"a1ps4wpe52qytvcvbsko09tapc", "data":{ "event":{ "createdDate":"2016-03-29T19:05:28.334Z", "replayId":55 }, "payload":"This is a message." }, "channel":"/u/TestStreaming" } Further cementing the evidence that Replayid is an integer, doing a metadata describe on EventBusSubcriber, the fields Tip and Position are both of type int with 9 digit precision. These two fields define the relative points in the stream between last event published versus last event consumed.
So, should I care? Or is an assumption of integers good enough?
Rationale for asking ... I was planning on a solution wherein I backed up incoming platform events to Sobjects by publishing out another platform event (which is guaranteed to publish even if the initial consuming transaction blows up on a Limits exception). Think of this a fallback backup solution.
The backup SObject had a uniquekey defined as the concatenation of the initial xxx__e sobjectType + Replayid. This strategy works fine if replayids are numbers as the unique key will be < 255 chars in length. But if Replayids can be 1000 characters long, I need to rethink things.
Side note ..to date in our org, Replayids have incremented up to about 1,000,000 for the most active xxx__e platform events