Does Sumo Logic have unique identifer for each ingested log message?

Sumo Logic has a "_messageid" metadata field that is the unique id associated with each message which helps in identifying each log message uniquely.

When any message gets ingested into Sumo Logic it adds some of the listed below metadata fields to each and every message:

messageId,sourceName,sourceHost,sourceCategory,messageTime,receiptTime,format,message

More information on each listed metadata field can be found here: Search-Metadata