What happens if I change the key of a SOW topic?

AMPS allows you to change the definition of a SOW topic in the configuration file, and restart the server.

However, when you do this, you should also delete the file containing the SOW. When the key for the SOW changes, AMPS can no longer guarantee that the messages in the SOW have unique keys. Updates to the SOW may have unexpected behavior, and SOW queries may return unexpected results.

Starting with AMPS 5.0, AMPS has safeguards to detect when the keys specified in a SOW definition do not match the keys that were used to generate an existing SOW file. To prevent data loss or incorrect results, AMPS will report an error and stop the startup process if there is a mismatch between the current configuration and the configuration used to create the SOW.