Service-oriented architecture (SOA) has been widely adopted for its ability to reduce the time, expense and risk of developing and deploying new software applications. But the benefits of SOA also bring increased requirements on the network, network management and network operations staff.
With SOA, each application is implemented using many individual software components. Each component carries out a single aspect of the application.
The payoff is that since each component carries out one action and one only, each is quick to implement and quick to test. Components can be reused across different applications when the same action -- such as accessing a particular type of data or verifying user credentials -- is required in multiple applications.
SOA enables rapid response to changing load. As the requirement for different types of transaction varies over the course of a month or even a day, SOA management software can start up additional copies of individual components on servers with unutilized capacity.
The line between application management and network management is becoming less distinct. Individual management packages that address one or the other must be replaced by packages that view that entire environment -- the application and the underlying network -- in a unified manner. Software products to address these needs are becoming available from vendors such as HP, CA and Progress Software as they acquire and integrate software from smaller vendors focused on one aspect of the problem.
Familiar measures of network performance, such as throughput, are less relevant in an SOA environment. In a traditional application environment, a user transaction typically results in a small number of data transfers between the user workstation and an application. With SOA, a single user transaction generates a very large number of interactions among the components carrying out the transaction. Each interaction includes only a small amount of data. Management tools designed to measure byte counts and packet rates become less relevant when no single data transfer is of sufficient duration to make a throughput measure meaningful.
Overall transaction rate and responsiveness are what matters. Productivity is measured by how rapidly user transactions are completed. Data rates and the time required for each interchange between components are a factor in transaction rate -- but only one factor. Management software must be able to detect problems at the application level and then be able to drill down to find the root of the problem.
SOA's ability to add capacity as the load varies means that network traffic patterns can vary from minute to minute. Management software must be able to detect problems and react to them quickly. It isn't sufficient to produce a report and then wait for an operator to make necessary changes. Management software must enable operators to define specific events such as congestion and specify actions for the software to take when it detects those events.
In addition to adding new requirements, traditional network management tasks increase in importance. Spreading an application across multiple components resident on different systems means that a failure anywhere in the network can bring down the entire application environment. The ability to detect and respond to impending problems becomes even more vital.
Managing security and responding to threats are also increasingly important with SOA. Individual components are designed to carry out a single action and depend on the security environment surrounding the network to protect them from attack. Management software must integrate with intrusion prevention hardware and software to react immediately to threats. Actions such as changing filters on router ports or shutting down links and rerouting traffic must be automated.
The complexity brought about by the large number of individual components and rapid changes in network flows makes it vital for management software to provide clear and understandable views and reports. The vast amount of raw information must be boiled down and only the essentials presented to operators.
Finally, network operations staff must develop a basic understanding of the nomenclature, components and basic structure of SOA. Otherwise they will be unable to view network operations as a whole and manage the network to deliver excellent application performance.
About the author:
David B. Jacobs of The Jacobs Group has more than 20 years of networking industry experience. He has managed leading-edge software development projects and consulted to Fortune 500 companies, as well as software startups.
