[jboss-jira] [JBoss JIRA] Commented: (JGRP-494) Investigate marshalling format to simplify wireshark / ethereal plugin

[ http://jira.jboss.com/jira/browse/JGRP-494?page=comments#action_12419504 ] Richard Achmatowicz commented on JGRP-494: ------------------------------------------ It may be that we need to reopen this issue. Here's the problem. When dissecting JGroups over TCP, we have to take account of two things due to the stream-orientation of TCP: (i) a large TP bundle may be split into several TCP fragments (ii) several small TP bundles may be placed into one TCP fragment Reassembly of TP bundles will occur at the receiving TCP peer end, but Wireshark captures the fragments before reassembly, in between the peers so to speak, and so the Wireshark plugin writer has to do the reassembly herself. Reassembling TCP fragments is very very simple if we have a field in the TP header which describes the length of the entire TP bundle. We can then say to Wireshark - "reassmble enough TCP fragments until you get a buffer with at least this length". Dissection on a complete TP bundle can then proceeed in a straightforward fashion. Without this information, we never know if we have a complete TP bundle in the buffer, and so have to dissect the TCP fragment "on the fly" - checking before each read from the buffer if we have enough data in the buffer left; in that case that there is not enough data, request the reading of another TCP fragment. This complicates processing quite a bit. So - in summary, having the total length of a TP bundle in the TP header would help greatly with TCP processing. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.jboss.com/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira