I dropped out of the telecom last week for a while and I missed that discussion. From my point of view, small message latency is the most important figure of merit.
I agree with Randy that there are two typical message types, very large and very small. Many applications consist of a data plane and a control plane. The data plane typically has predictable flows and needs high bandwidth, but not low latency. The control plane uses small messages (10-20 bytes). (You can get a feel for it by estimating the amount of data in a typical function call. How often do you pass 1KB in parameters?) The message traffic is sporadic and bursty. Latency is critical here because (1) the messages are generally smaller than the product of bandwidth and latency (1Gb/s * 1us = 125 bytes) and (2) you can't use pipelining to speed up a critical path that sends a message and waits for a response. Dominic Herity www.redplain.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: 02 June 2007 20:13 To: [email protected] Subject: tipc-discussion Digest, Vol 13, Issue 1 Send tipc-discussion mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/tipc-discussion or, via email, send a message with subject or body 'help' to [EMAIL PROTECTED] You can reach the person managing the list at [EMAIL PROTECTED] When replying, please edit your Subject line so it is more specific than "Re: Contents of tipc-discussion digest..." Today's Topics: 1. TIPC WG: Minutes of May 31, 2007 Meeting (Stephens, Allan) ---------------------------------------------------------------------- Message: 1 Date: Fri, 1 Jun 2007 13:35:36 -0700 >From: "Stephens, Allan" <[EMAIL PROTECTED]> Subject: [tipc-discussion] TIPC WG: Minutes of May 31, 2007 Meeting To: <[email protected]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" A phone meeting of the TIPC working group was held on May 31, 2007. Attendees: Al Stephens (Wind River) -- meeting chair; Jon Maloy (Ericsson); Randy MacLeod (Nortel); Dominic Herity (Red Plain); Elmer Horvath (Wind River) Minutes: 1. Meeting opening The meeting was called to order at 11:03 AM (EDT). 2. TIPC BOF at Ottawa Linux Symposium The agenda for the TIPC birds-of-a-feather session at OLS was agreed upon. Randy will begin with a short presentation about TIPC and his experiences as a user; Al will provide an update on development activities over the last year and outline the current roadmap for future development; Dominic will talk about Red Plain's experience in porting their distributed object product from IP to TIPC. All presentations will be kept short to allow significant time for questions and discussion with session attendees. ACTION: All presenters to distribute their slides for comment by June 15th (send to meeting attendees only). It was also agreed that the TIPC Working Group will not hold a June 28th conference call, as we will be meeting at the BOF around that time anyway. 3. TIPC Roadmap Al asked participants about their highest priorities for upcoming development of TIPC. Randy: 1) Control/data plane separation (as mentioned in previous emails); may be needed in Fall 2007 timeframe. 2) Improved support for non-continguous sk_buffs. This covers both the egress side of things (eg. the ability to create large messages using multiple chunks rather than a single large chunk, which may be unavailable due to memory fragmentation issues) and the ingress side of things (eg. the ability to handle non-linear messages and/or fragmented messages without having to copy their component parts into a single large chunk). Randy also stated that he was not aware of a near-term need for hierarchical TIPC by Nortel. Jon: 1) Support for up to 64 (or even 256) bearers to allow users to configure a distinct VLAN-based bearer for each neighbouring node in a cluster. [Note: Al observed that this can be done right now with a trival change to TIPC_MAX_BEARERS, but Jon would like to avoid allocating memory for these bearers until they are actually needed.] 2) Support for link subscriptions. [Note: This might be necessary to support the control/data plane separation Randy wants to achieve.] Jon also thinks that creating a TCP-based bearer for TIPC (possibly running directly over Ethernet, rather than over IP) might be desirable performance/reliability reasons. Al will discuss this info with his superiors and put together a tentative TIPC roadmap. 4. Mailing list issues Randy raised concerns about the stability of SourceForge, observing that the tipc-discussion mailing list has become somewhat unreliable at times, and downloads/web pages are sometimes inaccessible. Al suggested we discuss our concerns with other project developers at OLS, and see if they can suggest better alternatives (such as code.google.com). 5. TIPC message sizes Elmer is interested in knowing what "typical" message sizes are for TIPC users, as this info will allow the development team to concentrate performance optimization efforts on the most commonly used areas. Randy observed that applications he has encountered typically involve small numbers of small packets (i.e. 10's of bytes) or large numbers of large packets (i.e. 1000's of messages, each up to 50KB); in both cases, the messages were being sent in a connectionless manner. In the former case his expectation is that TIPC should provide excellent performance vs. UDP, while in the latter he would expect good performance (i.e. comparable, or better) vs. UDP. 6. Meeting close The meeting adjourned at 11:40. The next meeting will be at OLS, as mentioned previously. Please let me know of any errors or omissions. Regards, Al Stephens [END] ------------------------------ ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ------------------------------ _______________________________________________ tipc-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tipc-discussion End of tipc-discussion Digest, Vol 13, Issue 1 ********************************************** ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ tipc-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tipc-discussion
