I've changed the code to set driver memory to 100g, changed python code: import pyspark conf=pyspark.SparkConf().setMaster("local[64]").setAppName("Test1").set(key="spark.driver.memory", value="100g") sc=pyspark.SparkContext.getOrCreate(conf) rows=70000 data=list(range(rows)) rdd=sc.parallelize(data,rows) assert rdd.getNumPartitions()==rows rdd0=rdd.filter(lambda x:False) assert rdd0.getNumPartitions()==rows rdd00=rdd0.coalesce(1) data=rdd00.collect() assert data==[]
Still the same error happens: 21/04/09 04:48:38 WARN TaskSetManager: Stage 0 contains a task of very large size (4732 KiB). The maximum recommended task size is 1000 KiB. OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00007f4643550000, 16384, 0) failed; error='Not enough space' (errno=12) [423.701s][warning][os,thread] Attempt to protect stack guard pages failed (0x00007f4640d28000-0x00007f4640d2c000). [423.701s][warning][os,thread] Attempt to deallocate stack guard pages failed. [423.704s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 0k, detached. # # There is insufficient memory for the Java Runtime Environment to continue. # Native memory allocation (mmap) failed to map 16384 bytes for committing reserved memory. A function which needs 423 seconds to crash with excessive memory consumption when trying to coalesce 70000 empty partitions is not very practical. As I do not know the limits in which coalesce without shuffling can be used safely and with performance, I will now always use coalesce with shuffling, even though in theory this will come with quite a performance decrease. Markus Von: Russell Spitzer <russell.spit...@gmail.com> Gesendet: Donnerstag, 8. April 2021 15:24 An: Weiand, Markus, NMA-CFD <markus.wei...@bertelsmann.de> Cc: user@spark.apache.org Betreff: Re: possible bug Could be that the driver JVM cannot handle the metadata required to store the partition information of a 70k partition RDD. I see you say you have a 100GB driver but i'm not sure where you configured that? Did you set --driver-memory 100G ? On Thu, Apr 8, 2021 at 8:08 AM Weiand, Markus, NMA-CFD <markus.wei...@bertelsmann.de<mailto:markus.wei...@bertelsmann.de>> wrote: This is the reduction of an error in a complex program where allocated 100 GB driver (=worker=executor as local mode) memory. In the example I used the default size, as the puny example shouldn't need more anyway. And without the coalesce or with coalesce(1,True) everything works fine. I'm trying to coalesce an empty rdd with 70000 partitions in an empty rdd with 1 partition, why is this a problem without shuffling? Von: Sean Owen <sro...@gmail.com<mailto:sro...@gmail.com>> Gesendet: Donnerstag, 8. April 2021 15:00 An: Weiand, Markus, NMA-CFD <markus.wei...@bertelsmann.de<mailto:markus.wei...@bertelsmann.de>> Cc: user@spark.apache.org<mailto:user@spark.apache.org> Betreff: Re: possible bug That's a very low level error from the JVM. Any chance you are misconfiguring the executor size? like to 10MB instead of 10GB, that kind of thing. Trying to think of why the JVM would have very little memory to operate. An app running out of mem would not look like this. On Thu, Apr 8, 2021 at 7:53 AM Weiand, Markus, NMA-CFD <markus.wei...@bertelsmann.de<mailto:markus.wei...@bertelsmann.de>> wrote: Hi all, I'm using spark on a c5a.16xlarge machine in amazon cloud (so having 64 cores and 128 GB RAM). I'm using spark 3.01. The following python code leads to an exception, is this a bug or is my understanding of the API incorrect? import pyspark conf=pyspark.SparkConf().setMaster("local[64]").setAppName("Test1") sc=pyspark.SparkContext.getOrCreate(conf) rows=70000 data=list(range(rows)) rdd=sc.parallelize(data,rows) assert rdd.getNumPartitions()==rows rdd0=rdd.filter(lambda x:False) assert rdd0.getNumPartitions()==rows rdd00=rdd0.coalesce(1) data=rdd00.collect() assert data==[] output when starting from PyCharm: /home/ubuntu/PycharmProjects/<projekt-dir>/venv/bin/python /opt/pycharm-2020.2.3/plugins/python/helpers/pydev/pydevconsole.py --mode=client --port=41185 import sys; print('Python %s on %s' % (sys.version, sys.platform)) sys.path.extend(['/home/ubuntu/PycharmProjects/<projekt-dir>']) PyDev console: starting. Python 3.8.5 (default, Jan 27 2021, 15:41:15) [GCC 9.3.0] on linux import os os.environ['PYTHONHASHSEED'] = '0' runfile('/home/ubuntu/PycharmProjects/<projekt-dir>/tests/test.py', wdir='/home/ubuntu/PycharmProjects/<projekt-dir>/tests') WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by org.apache.spark.unsafe.Platform (file:/opt/spark/jars/spark-unsafe_2.12-3.0.1.jar) to constructor java.nio.DirectByteBuffer(long,int) WARNING: Please consider reporting this to the maintainers of org.apache.spark.unsafe.Platform WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release 21/04/08 12:12:26 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable 21/04/08 12:12:29 WARN TaskSetManager: Stage 0 contains a task of very large size (4732 KiB). The maximum recommended task size is 1000 KiB. [Stage 0:> (0 + 1) / 1][423.190s][warning][os,thread] Attempt to protect stack guard pages failed (0x00007f43d23ff000-0x00007f43d2403000). [423.190s][warning][os,thread] Attempt to deallocate stack guard pages failed. OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00007f43d300b000, 16384, 0) failed; error='Not enough space' (errno=12) [423.231s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 0k, detached. # # There is insufficient memory for the Java Runtime Environment to continue. # Native memory allocation (mmap) failed to map 16384 bytes for committing reserved memory. # An error report file with more information is saved as: # /home/ubuntu/PycharmProjects/<projekt-dir>/tests/hs_err_pid17755.log [thread 17966 also had an error] OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00007f4b7bd81000, 262144, 0) failed; error='Not enough space' (errno=12) ERROR:root:Exception while sending command. Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1207, in send_command raise Py4JNetworkError("Answer from Java side is empty") py4j.protocol.Py4JNetworkError: Answer from Java side is empty During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1033, in send_command response = connection.send_command(command) File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1211, in send_command raise Py4JNetworkError( py4j.protocol.Py4JNetworkError: Error while receiving ERROR:py4j.java_gateway:An error occurred while trying to connect to the Java server (127.0.0.1:42439<https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2F127.0.0.1%3A42439%2F&data=04%7C01%7C%7C96a91861f12c46dc454b08d8fa91a005%7C1ca8bd943c974fc68955bad266b43f0b%7C0%7C0%7C637534850695450752%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=dKfkds67mOAtrXSaWrv15vfMx7yUn%2Fjnwc58RdLhGt8%3D&reserved=0>) Traceback (most recent call last): File "/opt/spark/python/pyspark/rdd.py", line 889, in collect sock_info = self.ctx._jvm.PythonRDD.collectAndServe(self._jrdd.rdd()) File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1304, in __call__ return_value = get_return_value( File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py", line 334, in get_return_value raise Py4JError( py4j.protocol.Py4JError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.collectAndServe During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 977, in _get_connection connection = self.deque.pop() IndexError: pop from an empty deque During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1115, in start self.socket.connect((self.address, self.port)) ConnectionRefusedError: [Errno 111] Connection refused Traceback (most recent call last): File "/opt/spark/python/pyspark/rdd.py", line 889, in collect sock_info = self.ctx._jvm.PythonRDD.collectAndServe(self._jrdd.rdd()) File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1304, in __call__ return_value = get_return_value( File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py", line 334, in get_return_value raise Py4JError( py4j.protocol.Py4JError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.collectAndServe During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 977, in _get_connection connection = self.deque.pop() IndexError: pop from an empty deque During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1115, in start self.socket.connect((self.address, self.port)) ConnectionRefusedError: [Errno 111] Connection refused During handling of the above exception, another exception occurred: Traceback (most recent call last): File "<input>", line 3, in <module> File "/opt/pycharm-2020.2.3/plugins/python/helpers/pydev/_pydev_bundle/pydev_umd.py", line 197, in runfile pydev_imports.execfile(filename, global_vars, local_vars) # execute the script File "/opt/pycharm-2020.2.3/plugins/python/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc) File "/home/ubuntu/PycharmProjects/SPO_as_a_Service/tests/test_modeling_paf.py", line 992, in <module> test_70000() File "/home/ubuntu/PycharmProjects/SPO_as_a_Service/tests/test_modeling_paf.py", line 974, in test_70000 data=rdd00.collect() File "/opt/spark/python/pyspark/rdd.py", line 889, in collect sock_info = self.ctx._jvm.PythonRDD.collectAndServe(self._jrdd.rdd()) File "/opt/spark/python/pyspark/traceback_utils.py", line 78, in __exit__ self._context._jsc.setCallSite(None) File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1303, in __call__ answer = self.gateway_client.send_command(command) File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1031, in send_command connection = self._get_connection() File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 979, in _get_connection connection = self._create_connection() File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 985, in _create_connection connection.start() File "/opt/spark/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py", line 1127, in start raise Py4JNetworkError(msg, e) py4j.protocol.Py4JNetworkError: An error occurred while trying to connect to the Java server (127.0.0.1:42439<https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2F127.0.0.1%3A42439%2F&data=04%7C01%7C%7C96a91861f12c46dc454b08d8fa91a005%7C1ca8bd943c974fc68955bad266b43f0b%7C0%7C0%7C637534850695460748%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=nluVRqUTQeAfMp7ZuF5AdO6IELaRcr86xGkaW6RWOF0%3D&reserved=0>) report of free -m: total used free shared buff/cache available Mem: 127462 5548 22680 92 99233 120605 Swap: 0 0 0 Thanks Markus