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From ches...@apache.org
Subject [08/10] flink git commit: [FLINK-6798][docs] update old network buffer notices
Date Sun, 25 Jun 2017 11:50:29 GMT
[FLINK-6798][docs] update old network buffer notices

This closes #4080.


Project: http://git-wip-us.apache.org/repos/asf/flink/repo
Commit: http://git-wip-us.apache.org/repos/asf/flink/commit/31fd5825
Tree: http://git-wip-us.apache.org/repos/asf/flink/tree/31fd5825
Diff: http://git-wip-us.apache.org/repos/asf/flink/diff/31fd5825

Branch: refs/heads/release-1.3
Commit: 31fd58258b1346f3c9adcf397ffdec316333a4bd
Parents: 2bbfe02
Author: Nico Kruber <nico@data-artisans.com>
Authored: Tue Jun 6 14:24:14 2017 +0200
Committer: zentol <chesnay@apache.org>
Committed: Sun Jun 25 08:55:09 2017 +0200

----------------------------------------------------------------------
 docs/monitoring/large_state_tuning.md           | 20 +++++---------------
 .../flink/configuration/TaskManagerOptions.java |  4 ++--
 .../runtime/io/network/NetworkEnvironment.java  |  4 ++--
 3 files changed, 9 insertions(+), 19 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/flink/blob/31fd5825/docs/monitoring/large_state_tuning.md
----------------------------------------------------------------------
diff --git a/docs/monitoring/large_state_tuning.md b/docs/monitoring/large_state_tuning.md
index 9e1ecc7..a356970 100644
--- a/docs/monitoring/large_state_tuning.md
+++ b/docs/monitoring/large_state_tuning.md
@@ -94,21 +94,11 @@ When a savepoint is manually triggered, it may be in process concurrently
with a
 
 ## Tuning Network Buffers
 
-The number of network buffers is a parameter that can currently have an effect on checkpointing
at large scale.
-The Flink community is working on eliminating that parameter in the next versions of Flink.
-
-The number of network buffers defines how much data a TaskManager can hold in-flight before
back-pressure kicks in.
-A very high number of network buffers means that a lot of data may be in the stream network
channels when a checkpoint
-is started. Because the checkpoint barriers travel with that data (see [description of how
checkpointing works](../internals/stream_checkpointing.html)),
-a lot of in-flight data means that the barriers have to wait for that data to be transported/processed
before arriving
-at the target operator.
-
-Having a lot of data in-flight also does not speed up the data processing as a whole. It
only means that data is picked up faster
-from the data source (log, files, message queue) and buffered longer in Flink. Having fewer
network buffers means that
-data is picked up from the source more immediately before it is actually being processed,
which is generally desirable.
-The number of network buffers should hence not be set arbitrarily large, but to a low multiple
(such as 2x) of the
-minimum number of required buffers.
-
+Before Flink 1.3, an increased number of network buffers also caused increased checkpointing
times since
+keeping more in-flight data meant that checkpoint barriers got delayed. Since Flink 1.3,
the
+number of network buffers used per outgoing/incoming channel is limited and thus network
buffers
+may be configured without affecting checkpoint times
+(see [network buffer configuration](../setup/config.html#configuring-the-network-buffers)).
 
 ## Make state checkpointing Asynchronous where possible
 

http://git-wip-us.apache.org/repos/asf/flink/blob/31fd5825/flink-core/src/main/java/org/apache/flink/configuration/TaskManagerOptions.java
----------------------------------------------------------------------
diff --git a/flink-core/src/main/java/org/apache/flink/configuration/TaskManagerOptions.java
b/flink-core/src/main/java/org/apache/flink/configuration/TaskManagerOptions.java
index 8480045..bde564a 100644
--- a/flink-core/src/main/java/org/apache/flink/configuration/TaskManagerOptions.java
+++ b/flink-core/src/main/java/org/apache/flink/configuration/TaskManagerOptions.java
@@ -137,7 +137,7 @@ public class TaskManagerOptions {
 			.defaultValue(1024L << 20); // 1 GB
 
 	/**
-	 * Number of network buffers to use for each outgoing/ingoing channel (subpartition/input
channel).
+	 * Number of network buffers to use for each outgoing/incoming channel (subpartition/input
channel).
 	 *
 	 * Reasoning: 1 buffer for in-flight data in the subpartition + 1 buffer for parallel serialization
 	 */
@@ -146,7 +146,7 @@ public class TaskManagerOptions {
 			.defaultValue(2);
 
 	/**
-	 * Number of extra network buffers to use for each outgoing/ingoing gate (result partition/input
gate).
+	 * Number of extra network buffers to use for each outgoing/incoming gate (result partition/input
gate).
 	 */
 	public static final ConfigOption<Integer> NETWORK_EXTRA_BUFFERS_PER_GATE =
 			key("taskmanager.network.memory.floating-buffers-per-gate")

http://git-wip-us.apache.org/repos/asf/flink/blob/31fd5825/flink-runtime/src/main/java/org/apache/flink/runtime/io/network/NetworkEnvironment.java
----------------------------------------------------------------------
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/io/network/NetworkEnvironment.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/io/network/NetworkEnvironment.java
index cc4cb77..4269af6 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/io/network/NetworkEnvironment.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/io/network/NetworkEnvironment.java
@@ -73,9 +73,9 @@ public class NetworkEnvironment {
 
 	private final int partitionRequestMaxBackoff;
 
-	/** Number of network buffers to use for each outgoing/ingoing channel (subpartition/input
channel). */
+	/** Number of network buffers to use for each outgoing/incoming channel (subpartition/input
channel). */
 	private final int networkBuffersPerChannel;
-	/** Number of extra network buffers to use for each outgoing/ingoing gate (result partition/input
gate). */
+	/** Number of extra network buffers to use for each outgoing/incoming gate (result partition/input
gate). */
 	private final int extraNetworkBuffersPerGate;
 
 	private boolean isShutdown;


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