Monitoring

Q: What mechanism does AppFabric use to monitor its applications and services?
A: WCF/WF uses ETW (Event Tracing for Windows) to emit instrumentation events. AppFabric collects these events and places them in a centralized Monitoring Store using the Application Server Event Collector service. AppFabric tools then use this centralized store to query information about the services.

Q: What kinds of guarantees do you provide that instrumentation events will not be lost?

A: While our internal testing has not shown that the AppFabric system will drop events, we do not make guarantees around events. The WCF/WF NET Framework provides extensibility points for listeners and participants which can be used to guarantee reliable eventing.

Q: How do I deal with data recovery? Does AppFabric include tools for it?
A: If SQL Server is used as the monitoring database, SQL Server provides backup and restoration tooling for data recovery.

Q: I have several connected services. Can I use AppFabric to trace the message across these services and find where the failure occurs?
A: AppFabric provides support for finding related events between WCF/WF and related services to aid in finding the root cause of a failure.

Q: Can I enable/disable tracing at run time without having to bring the service down?

A: Yes, you can use WMI tools to dynamically enable/disable tracing. However, if you use the IIS Manager UI or PowerShell script the service will be gracefully recycled.