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https://issues.apache.org/jira/browse/FLINK-17923?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17118478#comment-17118478
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Dian Fu edited comment on FLINK-17923 at 5/28/20, 9:16 AM:
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[~xintongsong] Appreciated your suggestions. It makes sense to me.
I want to adjust the PR a bit as following:
- Set Python UDF to use managed memory by default.
- If Python UDF and RocksDB is used together, throw exceptions with meaningful
suggestions.
- If Python UDF is configured to use off-heap memory and the task off-heap
memory could not meet the requirement, throw exceptions with meaningful
suggestions.
In this case, when we support to let Python UDF and RocksDB both use managed
memory in the future, we could just remove the checks and there will be no
potential backward compatibility issues.
What do you think?
was (Author: dian.fu):
[~xintongsong] Appreciated your suggestions. It makes sense to me.
I want to adjust it a bit as following:
- Set Python UDF to use managed memory by default.
- If Python UDF and RocksDB is used together, throw exceptions with meaningful
suggestions.
- If Python UDF is configured to use off-heap memory and the task off-heap
memory could not meet the requirement, throw exceptions with meaningful
suggestions.
In this case, when we support to let Python UDF and RocksDB both use managed
memory in the future, we could just remove the checks and there will be no
potential backward compatibility issues.
What do you think?
> It will throw MemoryAllocationException if rocksdb statebackend and Python
> UDF are used in the same slot
> ----------------------------------------------------------------------------------------------------------
>
> Key: FLINK-17923
> URL: https://issues.apache.org/jira/browse/FLINK-17923
> Project: Flink
> Issue Type: Bug
> Components: API / Python, Runtime / State Backends
> Affects Versions: 1.10.0, 1.11.0
> Reporter: Dian Fu
> Priority: Blocker
> Labels: pull-request-available
> Fix For: 1.11.0
>
>
> For the following job:
> {code}
> import logging
> import os
> import shutil
> import sys
> import tempfile
> from pyflink.datastream import StreamExecutionEnvironment
> from pyflink.table import TableConfig, StreamTableEnvironment, DataTypes
> from pyflink.table.udf import udf
> def word_count():
> content = "line Licensed to the Apache Software Foundation ASF under one
> " \
> "line or more contributor license agreements See the NOTICE
> file " \
> "line distributed with this work for additional information " \
> "line regarding copyright ownership The ASF licenses this file
> " \
> "to you under the Apache License Version the " \
> "License you may not use this file except in compliance " \
> "with the License"
> t_config = TableConfig()
> env = StreamExecutionEnvironment.get_execution_environment()
> t_env = StreamTableEnvironment.create(env, t_config)
> # register Results table in table environment
> tmp_dir = tempfile.gettempdir()
> result_path = tmp_dir + '/result'
> if os.path.exists(result_path):
> try:
> if os.path.isfile(result_path):
> os.remove(result_path)
> else:
> shutil.rmtree(result_path)
> except OSError as e:
> logging.error("Error removing directory: %s - %s.", e.filename,
> e.strerror)
> logging.info("Results directory: %s", result_path)
> sink_ddl = """
> create table Results(
> word VARCHAR,
> `count` BIGINT
> ) with (
> 'connector' = 'blackhole'
> )
> """
> t_env.sql_update(sink_ddl)
> @udf(input_types=[DataTypes.BIGINT()], result_type=DataTypes.BIGINT())
> def inc(count):
> return count + 1
> t_env.register_function("inc", inc)
> elements = [(word, 1) for word in content.split(" ")]
> t_env.from_elements(elements, ["word", "count"]) \
> .group_by("word") \
> .select("word, count(1) as count") \
> .select("word, inc(count) as count") \
> .insert_into("Results")
> t_env.execute("word_count")
> if __name__ == '__main__':
> logging.basicConfig(stream=sys.stdout, level=logging.INFO,
> format="%(message)s")
> word_count()
> {code}
> It will throw the following exception if rocksdb state backend is used:
> {code}
> Caused by: org.apache.flink.util.FlinkException: Could not restore keyed
> state backend for KeyedProcessOperator_c27dcf7b54ef6bfd6cff02ca8870b681_(1/1)
> from any of the 1 provided restore options.
> at
> org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:135)
> at
> org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.keyedStatedBackend(StreamTaskStateInitializerImpl.java:317)
> at
> org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.streamOperatorStateContext(StreamTaskStateInitializerImpl.java:144)
> ... 9 more
> Caused by: java.io.IOException: Failed to acquire shared cache resource for
> RocksDB
> at
> org.apache.flink.contrib.streaming.state.RocksDBOperationUtils.allocateSharedCachesIfConfigured(RocksDBOperationUtils.java:212)
> at
> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.createKeyedStateBackend(RocksDBStateBackend.java:516)
> at
> org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.lambda$keyedStatedBackend$1(StreamTaskStateInitializerImpl.java:301)
> at
> org.apache.flink.streaming.api.operators.BackendRestorerProcedure.attemptCreateAndRestore(BackendRestorerProcedure.java:142)
> at
> org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:121)
> ... 11 more
> Caused by: org.apache.flink.runtime.memory.MemoryAllocationException: Could
> not created the shared memory resource of size 536870920. Not enough memory
> left to reserve from the slot's managed memory.
> at
> org.apache.flink.runtime.memory.MemoryManager.lambda$getSharedMemoryResourceForManagedMemory$8(MemoryManager.java:603)
> at
> org.apache.flink.runtime.memory.SharedResources.createResource(SharedResources.java:130)
> at
> org.apache.flink.runtime.memory.SharedResources.getOrAllocateSharedResource(SharedResources.java:72)
> at
> org.apache.flink.runtime.memory.MemoryManager.getSharedMemoryResourceForManagedMemory(MemoryManager.java:617)
> at
> org.apache.flink.runtime.memory.MemoryManager.getSharedMemoryResourceForManagedMemory(MemoryManager.java:566)
> at
> org.apache.flink.contrib.streaming.state.RocksDBOperationUtils.allocateSharedCachesIfConfigured(RocksDBOperationUtils.java:208)
> ... 15 more
> Caused by: org.apache.flink.runtime.memory.MemoryReservationException: Could
> not allocate 536870920 bytes. Only 454033416 bytes are remaining.
> at
> org.apache.flink.runtime.memory.MemoryManager.reserveMemory(MemoryManager.java:461)
> at
> org.apache.flink.runtime.memory.MemoryManager.lambda$getSharedMemoryResourceForManagedMemory$8(MemoryManager.java:601)
> ... 20 more
> {code}
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