I'd venture to say that the original form of middleware took the shape of a transaction monitor. As services come into greater play and distributed systems get, well, more distributed, the transaction monitor is again coming to the fore.
Now, increasingly, it is held that the best way now to understand the behavior of a complex distributed system is by ''following the transaction.'' This is apparent in a series of recent SOA news stories.
One result of Progress's 2008 purchase of MindReef was an enhanced version of the Progress Actional tool set that applies Actional Flow Mapping to Application X-Ray diagnostic software to trace individual transaction flows in production. Note that early SOA governance software suites are growing to cover all types of technology types.
With transactions, ''the whole is greater than the sum of its parts, '' reminds Ed Horst of AmberPoint. ''You have to track each transaction individually. They don't live in one spot." Read more in ''Transactions are the currency for SOA management.''
There is more. AutoPilot TransactionWorks from Nastel provides transactional discovery and operational data in one integrated set of capabilities, writes Gina Roos in a look at a new transaction offering. The software is said to reduce transactional latency and improve business transaction performance while helping users to identify and eliminate hidden costs, or "stealth waste," in their business processes, according to Roos's sources.
Roos also writes about a new application performance management (APM) offer from dynaTrace. DynaTrace's Purepath tracing technology follows and captures individual transactions down to the code level. The APM system also offloads all the data processing to dynaTrace's central server, giving customers very lightweight transaction tracking.
Services are plentiful, but non-service-oriented legacy is more so, and needs to be included in monitoring tasks. Stay tuned.