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Shixiong Zhu commented on SPARK-10086: -------------------------------------- I opened SPARK-13691 to describe the root issue in PySpark. > Flaky StreamingKMeans test in PySpark > ------------------------------------- > > Key: SPARK-10086 > URL: https://issues.apache.org/jira/browse/SPARK-10086 > Project: Spark > Issue Type: Bug > Components: MLlib, PySpark, Streaming, Tests > Affects Versions: 1.5.0 > Reporter: Joseph K. Bradley > Priority: Critical > Attachments: flakyRepro.py > > > Here's a report on investigating test failures in StreamingKMeans in PySpark. > (See Jenkins links below.) > It is a StreamingKMeans test which trains on a DStream with 2 batches and > then tests on those same 2 batches. It fails here: > [https://github.com/apache/spark/blob/1968276af0f681fe51328b7dd795bd21724a5441/python/pyspark/mllib/tests.py#L1144] > I recreated the same test, with variants training on: (1) the original 2 > batches, (2) just the first batch, (3) just the second batch, and (4) neither > batch. Here is code which avoids Streaming altogether to identify what > batches were processed. > {code} > from pyspark.mllib.clustering import StreamingKMeans, StreamingKMeansModel > batches = [[[-0.5], [0.6], [0.8]], [[0.2], [-0.1], [0.3]]] > batches = [sc.parallelize(batch) for batch in batches] > stkm = StreamingKMeans(decayFactor=0.0, k=2) > stkm.setInitialCenters([[0.0], [1.0]], [1.0, 1.0]) > # Train > def update(rdd): > stkm._model.update(rdd, stkm._decayFactor, stkm._timeUnit) > # Remove one or both of these lines to test skipping batches. > update(batches[0]) > update(batches[1]) > # Test > def predict(rdd): > return stkm._model.predict(rdd) > predict(batches[0]).collect() > predict(batches[1]).collect() > {code} > *Results*: > {code} > ####################### EXPECTED > [0, 1, 1] > > [1, 0, 1] > ####################### Skip batch 0 > [1, 0, 0] > [0, 1, 0] > ####################### Skip batch 1 > [0, 1, 1] > [1, 0, 1] > ####################### Skip both batches (This is what we see in the test > failures.) > [0, 1, 1] > [0, 0, 0] > {code} > Skipping both batches reproduces the failure. There is no randomness in the > StreamingKMeans algorithm (since initial centers are fixed, not randomized). > CC: [~tdas] [~freeman-lab] [~mengxr] > Failure message: > {code} > ====================================================================== > FAIL: test_trainOn_predictOn (__main__.StreamingKMeansTest) > Test that prediction happens on the updated model. > ---------------------------------------------------------------------- > Traceback (most recent call last): > File > "/home/jenkins/workspace/SparkPullRequestBuilder@3/python/pyspark/mllib/tests.py", > line 1147, in test_trainOn_predictOn > self._eventually(condition, catch_assertions=True) > File > "/home/jenkins/workspace/SparkPullRequestBuilder@3/python/pyspark/mllib/tests.py", > line 123, in _eventually > raise lastValue > File > "/home/jenkins/workspace/SparkPullRequestBuilder@3/python/pyspark/mllib/tests.py", > line 114, in _eventually > lastValue = condition() > File > "/home/jenkins/workspace/SparkPullRequestBuilder@3/python/pyspark/mllib/tests.py", > line 1144, in condition > self.assertEqual(predict_results, [[0, 1, 1], [1, 0, 1]]) > AssertionError: Lists differ: [[0, 1, 1], [0, 0, 0]] != [[0, 1, 1], [1, 0, 1]] > First differing element 1: > [0, 0, 0] > [1, 0, 1] > - [[0, 1, 1], [0, 0, 0]] > ? ^^^^ > + [[0, 1, 1], [1, 0, 1]] > ? +++ ^ > ---------------------------------------------------------------------- > Ran 62 tests in 164.188s > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org