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https://issues.apache.org/jira/browse/FLINK-17923?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17117260#comment-17117260
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Xintong Song commented on FLINK-17923:
--------------------------------------
[~pnowojski],
I posted all the 3 options that were mentioned in our offline discussion, for
public visibility.
Personally, I'm not a fan of option 2), because I also think it is an improper
temporary fix.
For option 3), as Jincheng mentioned, Zhu is already preparing a design doc
(ETA today). I understand that having people evaluating the design is already a
distraction from solving the release blockers. However, in this case I think it
would be ok to at least take a look at the design proposal before deciding
whether this should be fixed in 1.11.0, for its importance for python use cases
and the fact that people mostly involved with the proposed change (Jincheng &
Zhu) do not have much workload related to the release testing (that's what I
see from the current burndown board).
Additionally, if this fix does not make into 1.11.0 at the end, I would suggest
a really quick release 1.11.1 (potentially right after fixing this issue).
IIUC, the fix of this issue ideally should not affect any other scenarios
except for running both RocksDB & Python UDF together (which currently doesn't
work).
> 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
> 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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