Python AppEngine MapReduce
<p>i have created a pretty simple MapReduce pipeline, but i am having a cryptic:</p>

<p><code>PipelineSetupError: Error starting production.cron.pipelines.ItemsInfoPipeline(*(), **{})#a741186284ed4fb8a4cd06e38921beff:</code></p>

<p>when i try to start it. This is the pipeline code:</p>

<pre><code>class ItemsInfoPipeline(base_handler.PipelineBase):
"""
"""

    def run(self):
        output = yield mapreduce_pipeline.MapreducePipeline(
            job_name="items_job",
            mapper_spec="production.cron.mappers.items_info_mapper",
            input_reader_spec="mapreduce.input_readers.DatastoreInputReader",
            mapper_params={
                "input_reader": {
                    "entity_kind": "production.models.Transaction"
                }
            }
        )

        yield ItemsInfoStorePipeline(output)


class ItemsInfoStorePipeline(base_handler.PipelineBase):
"""
"""

    def run(self, statistics):
        print statistics
        return "OK"
</code></pre>

<p>Of course i have double checked that the mapper path is right, and take into account that ItemsInfoStorePipeline is not doing anything because i am focusing the have the pipeline started, which is not happening. </p>

<p>It is all triggered by a Flask view, the following:</p>

<pre><code>class ItemsInfoMRJob(views.MethodView):
"""

It's based on transacions.

"""

    def get(self):
    """

    :return:
    """
        pipeline = ItemsInfoPipeline()
        pipeline.start()

        redirect_url = "%s/status?root=%s" % (pipeline.base_path, pipeline.pipeline_id)

        return flask.redirect(redirect_url)
</code></pre>

<p>I am using <code>GoogleAppEngineMapReduce==1.9.22.0</code></p>

<p>Thanks for any help.</p>

<p><strong>UPDATE</strong></p>

<p>The above code works once deployed.</p>

<p><strong>UPDATE 2</strong></p>

<p>Apparently there's more people dealing with this:</p>

<p><a href="https://github.com/GoogleCloudPlatform/appengine-mapreduce/issues/103" rel="nofollow">https://github.com/GoogleCloudPlatform/appengine-mapreduce/issues/103</a></p>

<p>This was driving me nuts today. When I run in pycharm I don't get this errors - on command line I did:</p>

<pre><code>python /usr/local/google_appengine/dev_appserver.py app.yaml --port 8000 --host localhost --admin_port=8080 --port=8000
</code></pre>

<p>instead of:</p>

<pre><code>dev_appserver.py app.yaml --port 8000 --host localhost --admin_port=8080 --port=8000
</code></pre>

<p>... and now I don't get the error.</p>

python google-app-engine mapreduce google-app-engine-python