[NIFI-4420] On startup the component selection should take into account all known coordinates

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.4.0
• Component/s: Core Framework
• Assignee: Unassigned
• Reporter: Joe Witt
• Created: 25/Sep/17 17:10
• Updated: 09/Jan/18 00:20

Description

During the RC1 vote for Apache NiFi 1.4.0 there were some mistakenly duplicated LookupService/Controller services. That was wrong and needs to be fixed. It did, however, expose a condition we should be able to handle easily.

The case was a user with Apache NiFi 1.3.0 flow using nar1:LookupService:1.3.0 upgraded to NiFi 1.4.0 which contained both a nar1:LookupService:1.4.0 and nar2:LookupService:1.4.0.

His flow did not automatically upgrade nicely and instead he had to either delete and recreate the component or change its version. This is because right now on startup nifi notices the version that was being used is no longer available and it sees two different versions available so it doesn't know which one to select. However, that is only because it was not taking advantage of the group (nar1) and instead only used the class name. If it had used both the class name AND the group name it would have seen there is still only one version available and automatically chosen it.

So we should take advantage of the group information when selecting/determining which version to automatically select during an upgrade.