Hi Dave, Got your points, I appreciate your prompt and clear answers.
Best, Yong Chen -----Original Message----- From: Dave Shield [mailto:[EMAIL PROTECTED] Sent: Friday, October 21, 2005 1:50 AM To: Yong Chen (yongche) Cc: net-snmp-users@lists.sourceforge.net Subject: RE: Multiple sets in one pdu On Thu, 2005-10-20 at 13:49 -0700, Yong Chen (yongche) wrote: > 1. The RFC says assignments within one SET is "as if simultaneous", > does it imply there's no sequence guaranteed? Correct. > Further, does it imply "SET > redFish=xxx, blueFish=yyy" should have the same result as "SET > blueFish=yyy, redFish=xxx"? That is my understanding - yes. I'm not sure if there's any explicit text to this effect (and quite honestly, I don't have the time to search). But that is definitely the impression I have gained over the last ten years working with SNMP. If you want a definitive answer, I suggest you raise this issue on one of the IETF SNMP mailing lists. It's the IETF that decide on what the standards should say - not individual vendors. > 2. But how about if varbinds belong to 2 mibs? Most of the time, if varbinds belong to two different MIBs, then there typically won't be any interconnection between them. If there is, it's up to the MIB implementor(s) to arrange some agreed form of coordination. > Will agent sort the varbinds first to form 2 SETs as following? > > (1) SET fishTable.blueFish=xxx, > fishTable.redFish=yyy > (2) SET birdTable.yellowBird=aaa, > birdTable.greenBird=bbb Yes. > Then send (1) to fishTable handler, wait for response, and send (2) to > birdTable handler, wait for response, then combine both responses and > return? Yes. > How do you determine which handler is to be called first, fishTable > handler or birdTable handler? You don't. Your code must be able to handle either case. > In fishTable handler (and also birdTable handler), I can loop through > the varbind list to work around the sequence issue in case redFish has > to be set before blueFish. But how about if birdTable.yellowBird has > to be set before fishTable.redFish? (as indicated in the originally > received SET pdu), how do you enforce such order? One possibility would be to have the two table handlers set up an internal data structure, containing all the relevant assignments. This can clearly be done in any order (since it's purely an internal thing), and at a relatively early stage. Then once all updates have been applied, the next pass can activate this internal structure, working in whatever order is necessary for the underlying system. This doesn't have to match the order of the incoming varbinds. Remember, you've got four passes to play with - that gives a fair bit of flexibility for ensuring a particular ordering. Dave ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
