org.apache.flink.runtime.io.network.partition.ResultPartitionType Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.io.network.partition;
/**
* Type of a result partition.
*/
public enum ResultPartitionType {
/**
* Blocking partitions represent blocking data exchanges, where the data stream is first
* fully produced and then consumed. This is an option that is only applicable to bounded
* streams and can be used in bounded stream runtime and recovery.
*
* Blocking partitions can be consumed multiple times and concurrently.
*
*
The partition is not automatically released after being consumed (like for example the
* {@link #PIPELINED} partitions), but only released through the scheduler, when it determines
* that the partition is no longer needed.
*/
BLOCKING(false, false, false, false),
/**
* BLOCKING_PERSISTENT partitions are similar to {@link #BLOCKING} partitions, but have
* a user-specified life cycle.
*
*
BLOCKING_PERSISTENT partitions are dropped upon explicit API calls to the
* JobManager or ResourceManager, rather than by the scheduler.
*
*
Otherwise, the partition may only be dropped by safety-nets during failure handling
* scenarios, like when the TaskManager exits or when the TaskManager looses connection
* to JobManager / ResourceManager for too long.
*/
BLOCKING_PERSISTENT(false, false, false, true),
/**
* A pipelined streaming data exchange. This is applicable to both bounded and unbounded streams.
*
*
Pipelined results can be consumed only once by a single consumer and are automatically
* disposed when the stream has been consumed.
*
*
This result partition type may keep an arbitrary amount of data in-flight, in contrast to
* the {@link #PIPELINED_BOUNDED} variant.
*/
PIPELINED(true, true, false, false),
/**
* Pipelined partitions with a bounded (local) buffer pool.
*
*
For streaming jobs, a fixed limit on the buffer pool size should help avoid that too much
* data is being buffered and checkpoint barriers are delayed. In contrast to limiting the
* overall network buffer pool size, this, however, still allows to be flexible with regards
* to the total number of partitions by selecting an appropriately big network buffer pool size.
*
*
For batch jobs, it will be best to keep this unlimited ({@link #PIPELINED}) since there are
* no checkpoint barriers.
*/
PIPELINED_BOUNDED(true, true, true, false);
/** Can the partition be consumed while being produced? */
private final boolean isPipelined;
/** Does the partition produce back pressure when not consumed? */
private final boolean hasBackPressure;
/** Does this partition use a limited number of (network) buffers? */
private final boolean isBounded;
/** This partition will not be released after consuming if 'isPersistent' is true. */
private final boolean isPersistent;
/**
* Specifies the behaviour of an intermediate result partition at runtime.
*/
ResultPartitionType(boolean isPipelined, boolean hasBackPressure, boolean isBounded, boolean isPersistent) {
this.isPipelined = isPipelined;
this.hasBackPressure = hasBackPressure;
this.isBounded = isBounded;
this.isPersistent = isPersistent;
}
public boolean hasBackPressure() {
return hasBackPressure;
}
public boolean isBlocking() {
return !isPipelined;
}
public boolean isPipelined() {
return isPipelined;
}
/**
* Whether this partition uses a limited number of (network) buffers or not.
*
* @return true if the number of buffers should be bound to some limit
*/
public boolean isBounded() {
return isBounded;
}
public boolean isPersistent() {
return isPersistent;
}
}