while testing i was making calls to the predictor and asked for a user id that is out of range, the server threw an error internally and then stopped sending valid responses to requests.
i was making calls against the /predictions/ranks endpoint, look for top entries for a user.
the error seen in the logs was:
18/02/16 22:05:13 INFO DAGScheduler: Job 22 finished: lookup at MatrixFactorizationModel.scala:168, took 0.192751 s
Process Process-1:
Traceback (most recent call last):
File "/opt/rh/python27/root/usr/lib64/python2.7/multiprocessing/process.py", line 258, in _bootstrap
self.run()
File "/opt/rh/python27/root/usr/lib64/python2.7/multiprocessing/process.py", line 114, in run
self._target(*self._args, **self._kwargs)
File "/opt/app-root/src/predictions.py", line 99, in loop
int(req['topk']))
File "/opt/spark/python/lib/pyspark.zip/pyspark/mllib/recommendation.py", line 182, in recommendProducts
return list(self.call("recommendProducts", user, num))
File "/opt/spark/python/lib/pyspark.zip/pyspark/mllib/common.py", line 146, in call
return callJavaFunc(self._sc, getattr(self._java_model, name), *a)
File "/opt/spark/python/lib/pyspark.zip/pyspark/mllib/common.py", line 123, in callJavaFunc
return _java2py(sc, func(*args))
File "/opt/spark/python/lib/py4j-0.10.4-src.zip/py4j/java_gateway.py", line 1133, in __call__
answer, self.gateway_client, self.target_id, self.name)
File "/opt/spark/python/lib/pyspark.zip/pyspark/sql/utils.py", line 63, in deco
return f(*a, **kw)
File "/opt/spark/python/lib/py4j-0.10.4-src.zip/py4j/protocol.py", line 319, in get_return_value
format(target_id, ".", name), value)
Py4JJavaError: An error occurred while calling o53.recommendProducts.
: java.util.NoSuchElementException: next on empty iterator
at scala.collection.Iterator$$anon$2.next(Iterator.scala:39)
at scala.collection.Iterator$$anon$2.next(Iterator.scala:37)
at scala.collection.IndexedSeqLike$Elements.next(IndexedSeqLike.scala:63)
at scala.collection.IterableLike$class.head(IterableLike.scala:107)
at scala.collection.mutable.WrappedArray.scala$collection$IndexedSeqOptimized$$super$head(WrappedArray.scala:35)
at scala.collection.IndexedSeqOptimized$class.head(IndexedSeqOptimized.scala:126)
at scala.collection.mutable.WrappedArray.head(WrappedArray.scala:35)
at org.apache.spark.mllib.recommendation.MatrixFactorizationModel.recommendProducts(MatrixFactorizationModel.scala:168)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:280)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:214)
at java.lang.Thread.run(Thread.java:748)
172.17.0.1 - - [16/Feb/2018 22:05:14] "GET /predictions/ranks/fd3bb80ed43b4ab19fb139cf7454746b HTTP/1.1" 200 -
and all follow up calls, with good user ids return empty product sets, like this:
while testing i was making calls to the predictor and asked for a user id that is out of range, the server threw an error internally and then stopped sending valid responses to requests.
i was making calls against the
/predictions/ranks
endpoint, look for top entries for a user.the error seen in the logs was:
and all follow up calls, with good user ids return empty product sets, like this:
we probably just need to catch erroneous errors and figure out a way to keep the processing loop running.