The EmailPlus package uses caching techniques to avoid continually
retrieving information from the ClearQuest® database.
Caching minimizes the impact of evaluation and execution of the email
rules on the IBM® Rational® ClearQuest environment. Because the email
rules provide significant flexibility, construct the rules to ensure
that advanced rules minimize their own impact on performance. EmailPlus
caches in memory all rules for any given record type the first time
they are examined in any ClearQuest session.
Regardless of the number of rules a single record type has, only one
record is fetched from the database. The Simple EmailPlus rule phrases
are not evaluated by using ClearQuest queries.
Simple EmailPlus rule phrases are evaluated entirely in memory.
If you use the PostOffice transport mode, consider these points:
- This mode places additional load on the database. For each generated
email, a record and its history are created in the ClearQuest database. The relay service
that processes the record and subsequently deletes it incurs a corresponding
performance cost. Additionally, every time the relay service polls
the database for EmailPlusPostOffice records, a ClearQuest query is run against the database.
Find a balance between the number of queries and the number of records
that are processed at one time to even out the load. The additional
load on the database depends on the number, kind, and frequency of
email rules that are generating messages. Achieve balance by a process
of trial and error. Ideally, avoid having the relay service process
large numbers of records in a batch. Also avoid having the relay service
run too frequently.
- Email messages are delayed by approximately one MultiSite replication
cycle period if PostOffice records are not processed by a local instance
of the relay service.