/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.io.network;
import org.apache.flink.api.common.ExecutionMode;
import org.apache.flink.runtime.operators.shipping.ShipStrategyType;
/**
* Defines how the data exchange between two specific operators happens.
*/
public enum DataExchangeMode {
/**
* The data exchange is streamed, sender and receiver are online at the same time,
* and the receiver back-pressures the sender.
*/
PIPELINED,
/**
* The data exchange is decoupled. The sender first produces its entire result and finishes.
* After that, the receiver is started and may consume the data.
*/
BATCH,
/**
* The data exchange starts like in {@link #PIPELINED} and falls back to {@link #BATCH}
* for recovery runs.
*/
PIPELINE_WITH_BATCH_FALLBACK;
// ------------------------------------------------------------------------
public static DataExchangeMode getForForwardExchange(ExecutionMode mode) {
return FORWARD[mode.ordinal()];
}
public static DataExchangeMode getForShuffleOrBroadcast(ExecutionMode mode) {
return SHUFFLE[mode.ordinal()];
}
public static DataExchangeMode getPipelineBreakingExchange(ExecutionMode mode) {
return BREAKING[mode.ordinal()];
}
/**
* Computes the mode of data exchange to be used for a given execution mode and ship strategy.
* The type of the data exchange depends also on whether this connection has been identified to require
* pipeline breaking for deadlock avoidance.
* <ul>
* <li>If the connection is set to be pipeline breaking, this returns the pipeline breaking variant
* of the execution mode
* {@link org.apache.flink.runtime.io.network.DataExchangeMode#getPipelineBreakingExchange(org.apache.flink.api.common.ExecutionMode)}.
* </li>
* <li>If the data exchange is a simple FORWARD (one-to-one communication), this returns
* {@link org.apache.flink.runtime.io.network.DataExchangeMode#getForForwardExchange(org.apache.flink.api.common.ExecutionMode)}.
* </li>
* <li>If otherwise, this returns
* {@link org.apache.flink.runtime.io.network.DataExchangeMode#getForShuffleOrBroadcast(org.apache.flink.api.common.ExecutionMode)}.
* </li>
* </ul>
*
* @param shipStrategy The ship strategy (FORWARD, PARTITION, BROADCAST, ...) of the runtime data exchange.
* @return The data exchange mode for the connection, given the concrete ship strategy.
*/
public static DataExchangeMode select(ExecutionMode executionMode, ShipStrategyType shipStrategy,
boolean breakPipeline) {
if (shipStrategy == null || shipStrategy == ShipStrategyType.NONE) {
throw new IllegalArgumentException("shipStrategy may not be null or NONE");
}
if (executionMode == null) {
throw new IllegalArgumentException("executionMode may not mbe null");
}
if (breakPipeline) {
return getPipelineBreakingExchange(executionMode);
}
else if (shipStrategy == ShipStrategyType.FORWARD) {
return getForForwardExchange(executionMode);
}
else {
return getForShuffleOrBroadcast(executionMode);
}
}
// ------------------------------------------------------------------------
private static final DataExchangeMode[] FORWARD = new DataExchangeMode[ExecutionMode.values().length];
private static final DataExchangeMode[] SHUFFLE = new DataExchangeMode[ExecutionMode.values().length];
private static final DataExchangeMode[] BREAKING = new DataExchangeMode[ExecutionMode.values().length];
// initialize the map between execution modes and exchange modes in
static {
FORWARD[ExecutionMode.PIPELINED_FORCED.ordinal()] = PIPELINED;
SHUFFLE[ExecutionMode.PIPELINED_FORCED.ordinal()] = PIPELINED;
BREAKING[ExecutionMode.PIPELINED_FORCED.ordinal()] = PIPELINED;
FORWARD[ExecutionMode.PIPELINED.ordinal()] = PIPELINED;
SHUFFLE[ExecutionMode.PIPELINED.ordinal()] = PIPELINED;
BREAKING[ExecutionMode.PIPELINED.ordinal()] = BATCH;
FORWARD[ExecutionMode.BATCH.ordinal()] = PIPELINED;
SHUFFLE[ExecutionMode.BATCH.ordinal()] = BATCH;
BREAKING[ExecutionMode.BATCH.ordinal()] = BATCH;
FORWARD[ExecutionMode.BATCH_FORCED.ordinal()] = BATCH;
SHUFFLE[ExecutionMode.BATCH_FORCED.ordinal()] = BATCH;
BREAKING[ExecutionMode.BATCH_FORCED.ordinal()] = BATCH;
}
}