Return-Path: william@bourbon.usc.edu Delivery-Date: Tue Oct 28 07:28:44 2008 X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on merlot.usc.edu X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=AWL,BAYES_00, LOCALPART_IN_SUBJECT autolearn=no version=3.2.3 Received: from bourbon.usc.edu (bourbon.usc.edu [128.125.9.75]) by merlot.usc.edu (8.14.1/8.14.1) with ESMTP id m9SESijo004473 for ; Tue, 28 Oct 2008 07:28:44 -0700 Received: from bourbon.usc.edu (localhost.localdomain [127.0.0.1]) by bourbon.usc.edu (8.14.2/8.14.1) with ESMTP id m9SEdpoa028707 for ; Tue, 28 Oct 2008 07:39:51 -0700 Message-Id: <200810281439.m9SEdpoa028707@bourbon.usc.edu> To: cs551@merlot.usc.edu Subject: Re: cs551 Date: Tue, 28 Oct 2008 07:39:51 -0700 From: Bill Cheng Someone wrote: > One of the tests in the grading guidelines is the following > > (c) (+2 points) one beacon node, 3 regular nodes, linear network, > killing the only beacon node > > Restart the beacon node in the first window as follows: > ./sv_node c8-n07.ini > (wait for all nodes to start) > > in 2nd window, do: > ./sv_node c8-n04.ini > (wait for all nodes to start) > > in 3rd window, do: > ./sv_node c8-n09.ini > (wait for all nodes to start) > > in 4th window, do: > ./sv_node c8-n06.ini > > type "shutdown" in the 1st window > (all nodes should eventually shutdown) > > *wait* for all nodes to autoshutdown > > *in 5th window, do: > more ~/tmp/final1/n04/init_neighbor_list > more ~/tmp/final1/n09/init_neighbor_list > more ~/tmp/final1/n06/init_neighbor_list > (none of these files should exist)* > > in 5th window, do: > more ~/tmp/final1/n04/servant.log > more ~/tmp/final1/n09/servant.log > more ~/tmp/final1/n06/servant.log > > > In this, it is said that the init_neighbor_list file should not exist for > the non-beacon nodes (highlighted by bold above). What is the reason for > this ? You are talking about the (B.2.c) case where there is only one beacon node (node 07) with topology: topology: n07* <- n04 <- n09 <- n06 If you shutdown the beacon node, node 04 will flood a CHECK and CHECK would fail. Then it restarts. It has only node 07 in its init_neighbor_list and cannot connect to node 07, so it deletes its init_neighbor_list and restart. Then it cannot find any beacon node, so it quits. Node 09 and 06 should also do the same thing eventually. -- Bill Cheng // bill.cheng@usc.edu