Go library for sequential background processing.

This library depends on the watchdog and backoff libraries, which will reinvoke methods until success based on a given backoff strategy.

First, create an Executor. The alternate constructor, NewExecutorWithBackoff creates an executor instance with a non-default backoff strategy. The default strategy is an exponential strategy with some random jitter. Before scheduling a task, the executor must be started, which will begin processing the work queue in a goroutine.

executor := NewExecutor()
executor.Start()

Tasks can then be scheduled via the Schedule method. A task should be a method that returns true on success and false on failure. Each task is executed in the order that it was scheduled; task n will not begin until task n-1 has already successfully finished.

executor.Signal(func() bool {
    if ok := /* re-execute failed redis command */; ok {
        return true
    }

    fmt.Printf("Redis is still down.\n")
    return false
})

The user is also responsible for stopping the executor, which can be done by the following two methods. Use the Stop method if the executor should abandon the current task and ignore any queued tasks which have not yet been invoked. Use the Flush method instead to wait for all queued tasks to finish processing.

executor.Stop()  // immediate shutdown
executor.Flush() // graceful shutdown

Copyright (c) 2017 Eric Fritz

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