Opened 7 years ago

Last modified 4 years ago

#774 open enhancement

ACKSender study & optimizations

Reported by: Zlatin Balevsky Owned by: Zlatin Balevsky
Priority: minor Milestone:
Component: router/transport Version: 0.9.3
Keywords: SSU Cc: Zlatin Balevsky
Parent Tickets: Sensitive: no

Description

I'm seeing some evidence that reducing further the delay in acks improves throughput. Will investigate further.

See the attached chart of incoming bandwidth for details. The relevant code changes are

============================================================
--- router/java/src/net/i2p/router/transport/udp/ACKSender.java 1164f1c830ff99c0a7fd664fc9eba5ce34b93869
+++ router/java/src/net/i2p/router/transport/udp/ACKSender.java a50afcb1d0caf075cf03eb027e5fcc3daeb75bb5
@@ -28,7 +28,7 @@ class ACKSender implements Runnable {
     private static final long POISON_PS = -9999999999l;
     
     /** how frequently do we want to send ACKs to a peer? */
-    static final int ACK_FREQUENCY = 350;
+    static final int ACK_FREQUENCY = 50;
     
     public ACKSender(RouterContext ctx, UDPTransport transport) {
         _context = ctx;
@@ -77,9 +77,9 @@ class ACKSender implements Runnable {
         // if we are actively pumping lots of data to them, we can depend upon
         // the unsentACKThreshold to figure out when to send an ACK instead of
         // using the timer, so we can set the timeout/frequency higher
-        if (timeSinceACK < 2*1000)
-            return Math.max(rtt/2, ACK_FREQUENCY);
-        else
+//        if (timeSinceACK < 2*1000)
+//            return Math.max(rtt/2, ACK_FREQUENCY);
+//        else
             return ACK_FREQUENCY;
     }

the full (mostly unrelated) changes in the -zab-ackf build are here http://pastethis.i2p/show/2220/

Subtickets

Attachments (1)

bw-ackf.png (20.9 KB) - added by Zlatin Balevsky 7 years ago.
Incoming bandwidth on dev router

Download all attachments as: .zip

Change History (3)

Changed 7 years ago by Zlatin Balevsky

Attachment: bw-ackf.png added

Incoming bandwidth on dev router

comment:1 Changed 7 years ago by Zlatin Balevsky

Component: unspecifiedrouter/transport
Keywords: SSU added

comment:2 Changed 4 years ago by str4d

Status: newopen
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