Rally Metrics

This library allows your application to capture metrics and report them.

CORS Support

Rally Metrics now uses CORS to send its data to the Rally beacon. The img based GETs have been completely removed, CORS is your only option.

Tiny sandbox app

The tiny app at corsSandbox is meant to test CORS out easily, but it's also a nice smoketest to verify the beacon's working ok. See corsSandbox/README.md for more info

Limitations

Only one beginLoad/endLoad call per object at a time is supported

There is one important limitation to be aware of: any given object can only have one beginLoad/endLoad event in flight at a time. If a second beginLoad call is sent for an object while one is currently pending, it will be ignored.

Usage Guidelines

Try to keep these things in mind when using client metrics:

• Loads are tied to the last action: So it's important that an action has been called (typically based on a user action, such as a click) before a load begin/end is called. If not, the load will be tied to the previous action and will skew that action's total time.
• Be Conscise: Keep your client metrics as simple and to the point as possible to help with data aggregation. To keep your data shorter, there are just two things to be aware of:
  • use miscData sparingly.
  • Make your description strings unique and as short as possible. Generally speaking, the description string does not need to contain the name of the component. "reload due to timebox filter change" is better than "MyDefects panel reload due to timebox filter change". The client metric system can figure out what component is involved and appends the name and type of the component to the client metrics event.
  • Don't worry about data request URLs, the system is trimming them down automatically
• Provide a description whenever possible: Descriptions that give us some context as to why something happened are quite valuable. If you can give some context to the client metrics event, please do.
• Be sure the client metric calls are accurate: This sounds obvious, but in our experience with the panel timings we found it can be tough to truly know when something is done loading. The accuracy of the client metrics data is reliant on the calls being made at the correct time.
• Hook into data requests when possible: Sometimes getting into the data request to set the requester property is difficult. But if it's reasonable to do it, please do. The data request client metric events are valuable.