This error occurs when EUM Server not able to send data to Analytics and then we see following kind of error inside eum-processor.log:
Error code[400], Exception [RestException(statusCode=400, code=BulkError.UpsertLimitExceeded, errorMessage=Bulk upsert errors occurred for account <Account_Name> and event type [SessionRecord], developerMessage={"message":"Bulk upsert errors occurred for account<Account_Name> and event type [SessionRecord]"
...
...
message":"Failed [UpsertLimitException - maximum upserts of [1000] exceeded for docId [<App-Key>...]]
...
This is the issue which is related to UpsertLimitException as we have a limit on the number of upserts that can be called on a single request instance. This is due to the fact that each upsert operation appends additional nested documents to the original parent document and if the number of nested docs grows too large it can adversely affect the performance of ElasticSearch.
To increase the value for this, follow these steps:
- Property can be found under conf/events-service-api-store.properties as ad.es.event.maxUpsertsAllowed.
- Increase this value to a higher number.
- Restart the Events Service.
- Once restarted, kindly verify inside eum-processor if it's now able to send the events to analytics/ES and this error should not more be there.
Note: ad.es.event.maxUpsertsAllowed property controls how many segments can be inserted into a single document.
