ssf_scala

A Scala client for emitting spans in the Sensor Sensibility Format.

Features

• No dependencies, just boring Scala and Java stuff
• Asynchronous or Synchronous, your call!
• UDP only
• Option for max queue size when using asynchronous
• "Swallows" relevant exceptions (IO, Unresolveable) by default to prevent runtime errors breaking your service

Examples

import github.gphat.ssf_scala.Client

val c = new Client(hostname = "localhost", port = 8128, service = "my-service")
c.startSpan(name = "slowTask")
// ... Do a thing!
c.finishSpan(span)

Asynchronous (default behavior)

Metrics are locally queued via a BlockingQueue and emptied out in single ThreadExecutor thread. Messages are sent as quickly as the blocking take in that thread can fetch an item from the head of the queue.

You may provide a maxQueueSize when creating a client. Doing so will prevent the accidental unbounded growth of the metric send queue. If the limit is reached then new metrics will be dropped until the queue has room again. Logs will be emitted in this case for every consecutiveDropWarnThreshold drops. You can adjust this when instantiating a client.

Note: You can call c.shutdown to forcibly end things. The threads in this executor are flagged as deaemon threads so ending your program will cause any unsent metrics to be lost.

Synchronous

If you instantiate the client with asynchronous=false then the various metric methods will immediately emit your metric synchronously using the underlying sending mechanism. This might be great for UDP but other backends may have a high penalty!

val c = new Client(asynchronous = false)

Updating protobuf definition

$ scalapbc -I ~/go/src/github.com/stripe/veneur ~/go/src/github.com/stripe/veneur/ssf/sample.proto --scala_out=.