Rendezvous Subjects
The Rendezvous subjects you configure for conversion must be distinct.
The adapter validates the subject attribute of each tag, using the following rules:
- Within the scope of a
servicetag, the subjects of the tags must not collide with one another.This restriction does not apply between tags that are in different
servicetags. - If a literal subject is identical to a previous literal subject, then they collide (not permitted).
- If a literal subject matches a previous wildcard subject, then they do not collide (permitted).
- If a wildcard subject matches a previous literal subject, then they do not collide (permitted).
- If a wildcard subject matches a previous wildcard subject, then they collide (not permitted).
Examples
| Subject 1 | Subject 2 | Conformance |
|---|---|---|
| a.b | a.b.c | Permitted |
| a.b | a.* | Permitted |
| a.* | a.b | Permitted |
| a.b | a.> | Permitted |
| a.> | a.b | Permitted |
| a.b | a.b | Collide |
| a.* | a.> | Collide |
| a.> | a.* | Collide |
| a.* | *.b | Collide |
| *.b | a.* | Collide |
Messages that Match Two Rendezvous Subjects
The restriction against colliding subjects helps ensure that the adapter translates each Rendezvous message at most once.
The adapter forbids combinations in which two wildcard subjects collide, preventing ambiguity.
The adapter permits combinations in which a message might match both a literal subject and a wildcard subject. In this situation, the adapter translates the message according to the tag that specified the literal subject.