What Is Tungsten Monitor?

Tungsten Monitor provides pluggable monitoring for resources in database clusters. By resources we mean the various processes and network services that compose clusters, such as database servers, replicators, and middleware processes. Tungsten Monitor helps answer the following types of questions:

• What type of resource are we monitoring?
• What is the resource name?
• Is the resource online (up) or offline (down)?
• If a database, what is the latency of this copy of data?

Tungsten Monitor implements a simple check/notify loop in which a check runs on one or more resources and turns over the results to a notifier, which performs an action to send out the status.  Both check and notifier logic are plug-ins that implement the Checker and Notifier interfaces respectively.  Users can switch plug-ins as well as implement new types of tests easily.

Tungsten Monitor is a critical component for other Tungsten services, including the Tungsten Manager and Tungsten SQL Router.  Both of these components depend on resource status notifications from Tungsten Monitor to perform administrative actions like recording the overall resource role and to control operations like load-balancing that depend on up-to-date information on resource latency.