rsliter

version: 2
jobs:
    build:
        docker:
            - image: circleci/python:3.6.2-stretch-browsers
        steps:
            - checkout
            - run: pip install --user -r requirements.txt

rsliter

org.apache.kafka.connect.errors.ConnectException: Exiting WorkerSinkTask due to unrecoverable exception.
        at org.apache.kafka.connect.runtime.WorkerSinkTask.deliverMessages(WorkerSinkTask.java:546)
        at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:302)
        at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:205)
        at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:173)
        at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
        at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
        at java.util.concurrent.Executors.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

rsliter

[2018-09-20 19:12:06,087] ERROR WorkerSinkTask{id=shop-analytics-stats-hourly-3} Task threw an uncaught and unrecoverable exception (org.apache.kafka.connect.runtime.WorkerTask)
org.apache.kafka.common.errors.WakeupException
        at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.maybeTriggerWakeup(ConsumerNetworkClient.java:489)
        at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:274)
        at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:233)
        at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:209)
        at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.commitOffsetsSync(ConsumerCoordinator.java:597)
        at org.apache.kafka.clients.consumer.KafkaConsumer.commitSync(KafkaConsumer.java:1257)
        at org.apache.kafka.connect.runtime.WorkerSinkTask.doCommitSync(WorkerSinkTask.java:313)
        at org

rsliter

# The design pattern to create singleton CLASSES is pretty familiar-- it restricts the instantiation of a
# class to a single object. Eigenclasses in Ruby, however, allow you to restrict methods to a particular
# instance of a class. Eigenclasses also allow for restricted class methods.
#
# Hence, eigenclasses contain an object's singleton METHODS.

class Lupus
  def is_a_wolf?
    true
  end

rsliter

# Closures can be done in Ruby using both lambdas and procs.


# Lambdas with closures:
# A lambda can be declared so that it is created at runtime but evaluated only when it is called.

class Person
  def initialize(age)
    @age = age
  end

rsliter

I put together a handful of gists in order to dip my toes into functional programming and understand exactly how closures in both JavaScript and Ruby work.

Definition of a closure

A closure is a function that can be passed around in order to be called later. Its other property (the one that screws programmers up :) is the fact that the variable values persist from the time the function is created. It can then access the variables even after they lose scope/change values.

My explanations and examples:

Closures in JavaScript: https://gist.github.com/45ba3ef454d9696d2bb5
Closures in Ruby: https://gist.github.com/4196841

References: