Package com.vaadin.observability.micrometer.trace

Class TracingExecutor

java.lang.Object
com.vaadin.observability.micrometer.trace.TracingExecutor
All Implemented Interfaces:
Executor
public class TracingExecutor extends Object implements Executor
Wraps the Vaadin service Executor so that
  1. the trace context (and any other ThreadLocalAccessor-backed state) active when a task is submitted is restored when the task runs; and
  2. each task gets its own vaadin.ui.access span when an ObservationRegistry is supplied. The span is parented to the propagated trace, so work handed to the executor from a request thread ends up with a continuous trace tree across the thread hop.

The service executor is what Vaadin uses to dispatch signal effects and result notifications, and what applications are expected to use for their own background tasks (typically ones that end with UI.access(...)); it is not used by UI.access itself, which runs pending commands on the thread that unlocks the session.

Use wrap(Executor, ObservationRegistry) rather than the constructors so that an ExecutorService delegate keeps its lifecycle methods: Vaadin shuts its default executor down on service destroy, and only does so when the executor still is an ExecutorService.

  • Constructor Details

    • TracingExecutor

      public TracingExecutor(Executor delegate)

    • TracingExecutor

      public TracingExecutor(Executor delegate, io.micrometer.observation.ObservationRegistry observationRegistry)

  • Method Details

    • wrap

      public static Executor wrap(Executor delegate, io.micrometer.observation.ObservationRegistry observationRegistry)
      Wraps the given executor for tracing, preserving the ExecutorService contract when the delegate implements it.

      Wrapping is idempotent: an executor that already traces is returned as-is.

      Parameters:
      delegate - the executor to wrap, not null
      observationRegistry - the registry used to create the per-task span, may be null to only propagate the context
      Returns:
      the tracing executor

    • execute

      public void execute(Runnable command)
      Specified by:
      execute in interface Executor

    • instrument

      protected final Runnable instrument(Runnable command)
      Captures the current context and returns a task that restores it and opens a vaadin.ui.access span before running command.

      Must be called on the submitting thread, since that is where the context to propagate lives.

      Parameters:
      command - the task to instrument, not null
      Returns:
      the instrumented task

    • instrument

      protected final <T> Callable<T> instrument(Callable<T> task)
      Callable counterpart of instrument(Runnable), used by the ExecutorService submission methods.
      Type Parameters:
      T - the task result type
      Parameters:
      task - the task to instrument, not null
      Returns:
      the instrumented task