[jboss-jira] [JBoss JIRA] Resolved: (JGRP-560) Message greater than 16286 bytes is not received on MaxOS

Message greater than 16286 bytes is not received on MaxOS --------------------------------------------------------- Key: JGRP-560 URL: http://jira.jboss.com/jira/browse/JGRP-560 Project: JGroups Issue Type: Bug Reporter: Bela Ban Assigned To: Bela Ban Fix For: 2.6 I'm new to JGroups, and I have a Mac OS X (10.4)-specific question. I've used JGroups 2.4.1sp3, 2.5.0CR1, and the new 2.5.0GA - I see the same issue with all versions. I've noticed that, for UDP, there seems to be a max message size of 16286 bytes (a little less than 16K). This is using the default udp.xml config, and just a simple message to another node like: JChannel ch = new JChannel("udp.xml"); ch.setReceiver(this); ch.connect("TEST"); // // 'target' is another group member besides myself // byte[] buf = new byte[size]; Arrays.fill(buf, (byte)77); echo("Sending message: " + size + " bytes"); Message msg = new Message(target, null, buf); ch.send(msg); A receiver node will NOT receive the message if 'size' is greater than 16286. In fact, after sending a too-large message, the receiver sees no message trafffic so it starts doing heartbeats and view changes). I've attached some debug output below. TCP transport does not have this problem. I'm aware of the tos="8" attribute warning in OS X, and changing the value to 0 to avoid the warning doesn't affect the max size issue. Though perhaps it's the same Mac quirk causing both problems... I've searched around, but haven't seen anything about this. Is it a known issue? Is there a workaround? Am I doing something wrong? Thanks in advance, Rick Pike Debug output: ------------------------- SENDER: (Sends increasing size messages, 2 sec apart. As soon as the size goes beyond 16286, it notices a problem). Sending message: 16284 bytes Sending message: 16285 bytes Sending message: 16286 bytes 2007-07-17 12:06:25,934 [DEBUG] FD sending are-you-alive msg to 192.168.2.71:51607 (own address=192.168.2.71:51610) 2007-07-17 12:06:25,936 [DEBUG] FD received ack from 192.168.2.71:51607 Sending message: 16287 bytes Sending message: 16288 bytes RECEIVER: (Gets messages OK until 16287. I assume FD starts because it sees no message traffic.) Received message: 16284 bytes Received message: 16285 bytes Received message: 16286 bytes 2007-07-17 12:06:25,876 [DEBUG] FD sending are-you-alive msg to 192.168.2.71:51610 (own address=192.168.2.71:51607) 2007-07-17 12:06:25,884 [DEBUG] FD received ack from 192.168.2.71:51610 2007-07-17 12:06:29,305 [DEBUG] MERGE2 initial_mbrs=[[own_addr=192.168.2.71:51610, coord_addr=192.168.2.71:51607, is_server=true], [own_addr=192.168.2.71:51607, coord_addr=192.168.2.71:51607, is_server=true]] 2007-07-17 12:06:35,877 [DEBUG] FD sending are-you-alive msg to 192.168.2.71:51610 (own address=192.168.2.71:51607) 2007-07-17 12:06:35,880 [DEBUG] FD received ack from 192.168.2.71:51610 2007-07-17 12:06:42,496 [DEBUG] MERGE2 initial_mbrs=[[own_addr=192.168.2.71:51610, coord_addr=192.168.2.71:51607, is_server=true], [own_addr=192.168.2.71:51607, coord_addr=192.168.2.71:51607, is_server=true]] 2007-07-17 12:06:45,879 [DEBUG] FD sending are-you-alive msg to 192.168.2.71:51610 (own address=192.168.2.71:51607) 2007-07-17 12:06:45,880 [DEBUG] FD received ack from 192.168.2.71:51610 2007-07-17 12:06:50,453 [DEBUG] FD_SOCK peer closed socket normally 2007-07-17 12:06:50,453 [DEBUG] FD_SOCK pinger thread terminated