[FLINK-6798][docs] update old network buffer notices

This closes #4080.

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
 

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")

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;