Scaling up Apama
Apama provides services for real-time matching on streams of events against hundreds of different applications concurrently. This level of capacity is made possible by the advanced matching algorithms developed for Apama's correlator component and the scalability features of the correlator platform.
Should it prove necessary, capacity can further be increased by using multiple correlators on multiple hosts. To facilitate such multi-process deployments, Apama provides features to enable connecting components to pass events between them. It is recommended that each correlator is run on a separate host, to assist in the configuration of scaled-up topologies. However, it is possible to run multiple correlators on a single host. There are two methods of configuration:
Using the configuration tools from the command line or Apama macros for Ant.
Programmatically through a client programming API.
This guide describes both approaches, but first discusses different ways in which Apama can be distributed and what factors affect the choice of the distribution strategy.
Note: This topic focuses on scaling Apama for applications written in EPL. JMon has less scaling features as it does not support the use of multiple contexts. Java plug-ins can be used if invocation of Java code is required on multiple threads, either directly from EPL or by registering an event handler. See
Using Java plug-ins. Knowledge of aspects of EPL is assumed, specifically monitors, spawning, listeners and channels. Definitions of these terms can be found in
Getting Started with Apama EPL in
Developing Apama Applications.
The core event processing and matching service offered by Apama is provided by one or more correlator processes. In a simple deployment, Apama comprises a single correlator connected directly to at least one input event feed and output event receiver. Although this arrangement is suitable for a wide variety of applications (the actual size depending on the hardware in use, networking, and other available resources), for some high-end applications it may be necessary to scale up Apama by deploying multiple correlator processes on multiple hosts to partition the workload across several machines.