I am currently creating multiple Journey's in Journey Builder, and was under the impression that once a subscriber completed the Journey they would be able to re-enter it regardless if 'Contact Entry' is set to Single or Multiple. I have not been able to successfully accomplish this.
I'm using a Fire Event in Automation Studio to inject the users. This is working as expected, as they enter the Journey and complete one of the routes. But any following Fire Event will ignore these users entirely, even if they still meet the entry criteria.
To test, I added a few records using Contact Builder into the Data Extensions, and these new records would be the only ones added. Looking at the Event History for my entry trigger, it shows neither rejected or accepted for the users that already completed the Journey – they are ignored entirely.
Is this typical behaviour or is there something I am missing? Any help is appreciated, thank you.
Best Answer
This sounds like a "high water-mark" issue. Was new data added to the data extension? If not, the Interaction or Fire Event activity may be running as intended, but not detecting new rows because they were not added.
Journey Builder tracks the last event processed for the event source data extension to prevent individual events from being injected into an interaction more than once. This is known as the "High Water Mark." When an event is run, only records in the event source data extension above the High Water Mark will be processed. Records below the High Water Mark will be ignored.
This becomes problematic if an event source data extension has a primary key set on the field related to Subscriber Key. If an import or query activity is updating records in the event source data extension, they will not be assigned a new row in the data extension. This means that for contacts who may now meet filter criteria for the trigger, but who did not on previous runs of the entry event, they will still not be injected since they fall below the High Water Mark.
In order to avoid issues with the High Water Mark, it is recommended as a best practice to either use no primary key on the event source data extension, or to use a primary key other than Contact Key, Email Address, Mobile Number, or Device ID. You can also use an "overwrite" method for your import/query into the Event Source Data Extension.