Overview
webMethods FIX Module provides functionality to allow clustering to ensure high system availability. This chapter describes what clustering is and how to implement it in FIX Module.
Clustering is an advanced feature of the webMethods product suite that substantially extends the scalability, availability, and reliability of Integration Server. Clustering accomplishes this by providing the infrastructure and tools to deploy multiple Integration Servers as if they were a single virtual server, thereby allowing applications to leverage that architecture.
Clustering provides the following benefits:
Scalability. Without clustering, only
vertical scalability is possible. Requirements for increased capacity can only be met by deploying larger, more powerful machines, typically housing multiple CPUs. Clustering provides
horizontal scalability, virtually limitless expansion of capacity by simply adding more machines of the same or similar capacity.
Availability. Without clustering, even with expensive fault-tolerant systems, a system failure (hardware, java runtime, or software) may result in unacceptable downtime. Clustering provides virtually uninterrupted availability by deploying applications on multiple
Integration Servers; in the worst case, a server failure produces degraded but not disrupted service.
Reliability. Unlike a server farm (an independent set of servers), clustering provides the reliability required for mission-critical applications. Distributed applications must address network, hardware, and software errors that might produce duplicate (or failed) transactions. Clustering makes it possible to deliver “exactly once” execution as well as checkpoint/restart functionality for critical operations.
For complete information about Integration Server clustering, see the webMethods Integration Server Clustering Guide for your release.
When FIX Module is used in a clustered environment, it operates as follows:
In an
Integration Server cluster, only one
FIX Module node in the cluster is connected to the Appia engine at one time.
If the
FIX Module node that is connected to the Appia engine goes down, one of the other
FIX Module nodes in the
Integration Server cluster automatically connects to the Appia engine.
The client can send a FIX message by connecting to any of the
FIX Module nodes in the
Integration Server cluster.
The
FIX Module node that is directly connected to the Appia engine handles the actual exchange of FIX messages with the Appia engine. (The connected node serves as the intermediary between the Appia engine and
FIX Module instances.)