title: How to fix the error "AirflowException("Hostname of job runner does not match")"?
body: <p>I'm running airflow on my computer (Mac AirBook, 1.6 GHz Intel Core i5 and 8 GB 2133 MHz LPDDR3). A DAG with several tasks, failed with below error. Checked several articles online but with little to no help. There is nothing wrong with the task itself(double checked).</p>
  
  <p>Any help is much appreciated.</p>
  
  <pre><code>[2019-08-27 13:01:55,372] {sequential_executor.py:45} INFO - Executing command: ['airflow', 'run', 'Makefile_DAG', 'normalize_companies', '2019-08-27T15:38:20.914820+00:00', '--local', '--pool', 'default_pool', '-sd', '/home/airflow/dags/makefileDAG.py']
  [2019-08-27 13:01:56,937] {settings.py:213} INFO - settings.configure_orm(): Using pool settings. pool_size=5, max_overflow=10, pool_recycle=1800, pid=40647
  [2019-08-27 13:01:57,285] {__init__.py:51} INFO - Using executor SequentialExecutor
  [2019-08-27 13:01:59,423] {dagbag.py:90} INFO - Filling up the DagBag from /home/airflow/dags/makefileDAG.py
  [2019-08-27 13:02:01,736] {cli.py:516} INFO - Running &lt;TaskInstance: Makefile_DAG.normalize_companies 2019-08-27T15:38:20.914820+00:00 [queued]&gt; on host ajays-macbook-air.local
  Traceback (most recent call last):
    File "/anaconda3/envs/airflow/bin/airflow", line 32, in &lt;module&gt;
      args.func(args)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/utils/cli.py", line 74, in wrapper
      return f(*args, **kwargs)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/bin/cli.py", line 522, in run
      _run(args, dag, ti)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/bin/cli.py", line 435, in _run
      run_job.run()
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/jobs/base_job.py", line 213, in run
      self._execute()
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/jobs/local_task_job.py", line 111, in _execute
      self.heartbeat()
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/jobs/base_job.py", line 196, in heartbeat
      self.heartbeat_callback(session=session)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/utils/db.py", line 70, in wrapper
      return func(*args, **kwargs)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/jobs/local_task_job.py", line 159, in heartbeat_callback
      raise AirflowException("Hostname of job runner does not match")
  airflow.exceptions.AirflowException: Hostname of job runner does not match
  [2019-08-27 13:05:05,904] {sequential_executor.py:52} ERROR - Failed to execute task Command '['airflow', 'run', 'Makefile_DAG', 'normalize_companies', '2019-08-27T15:38:20.914820+00:00', '--local', '--pool', 'default_pool', '-sd', '/home/airflow/dags/makefileDAG.py']' returned non-zero exit status 1..
  [2019-08-27 13:05:05,905] {scheduler_job.py:1256} INFO - Executor reports execution of Makefile_DAG.normalize_companies execution_date=2019-08-27 15:38:20.914820+00:00 exited with status failed for try_number 2
  </code></pre>
  
  <p>Logs from the task:</p>
  
  <pre><code>[2019-08-27 13:02:13,616] {bash_operator.py:115} INFO - Running command: python /home/Makefile_Redo/normalize_companies.py
  [2019-08-27 13:02:13,628] {bash_operator.py:124} INFO - Output:
  [2019-08-27 13:05:02,849] {logging_mixin.py:95} INFO - [[34m2019-08-27 13:05:02,848[0m] {[34mlocal_task_job.py:[0m158} [33mWARNING[0m - [33mThe recorded hostname [1majays-macbook-air.local[0m does not match this instance's hostname [1mAJAYs-MacBook-Air.local[0m[0m
  [2019-08-27 13:05:02,860] {helpers.py:319} INFO - Sending Signals.SIGTERM to GPID 40649
  [2019-08-27 13:05:02,861] {taskinstance.py:897} ERROR - Received SIGTERM. Terminating subprocesses.
  [2019-08-27 13:05:02,862] {bash_operator.py:142} INFO - Sending SIGTERM signal to bash process group
  [2019-08-27 13:05:03,539] {taskinstance.py:1047} ERROR - Task received SIGTERM signal
  Traceback (most recent call last):
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/models/taskinstance.py", line 922, in _run_raw_task
      result = task_copy.execute(context=context)
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/operators/bash_operator.py", line 126, in execute
      for line in iter(sp.stdout.readline, b''):
    File "/anaconda3/envs/airflow/lib/python3.6/site-packages/airflow/models/taskinstance.py", line 899, in signal_handler
      raise AirflowException("Task received SIGTERM signal")
  airflow.exceptions.AirflowException: Task received SIGTERM signal
  [2019-08-27 13:05:03,550] {taskinstance.py:1076} INFO - All retries failed; marking task as FAILED
  </code></pre>
  
  <p>A weird thing I noticed from above log is:
  The recorded hostname [1majays-macbook-air.local[0m does not match this instance's hostname [1mAJAYs-MacBook-Air.local[0m[0m</p>
  
  <p>How is this possible and any solution to fix this?</p>