Attachment 591834 Details for Bug 830799 – Proposed patch - part 3 - Enhance downlist selection algorithm

[patch] Proposed patch - part 3 - Enhance downlist selection algorithm

2012-06-14-0001-cpg-Enhance-downlist-selection-algorithm.patch (text/plain), 1.63 KB, created by Jan Friesse on 2012-06-14 13:24:15 UTC

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Creator: Jan Friesse

Created: 2012-06-14 13:24:15 UTC

Size: 1.63 KB

patch

obsolete

>From 94a517e8eb5bc8d1fc81381356cc7bf12db6bce2 Mon Sep 17 00:00:00 2001
>From: Jan Friesse <jfriesse@redhat.com>
>Date: Thu, 14 Jun 2012 09:13:47 +0200
>Subject: [PATCH] flatiron cpg: Enhance downlist selection algorithm
>
>Let's say we have 2 nodes:
>- node 2 is paused
>- node 1 create membership (one node)
>- node 2 is unpaused
>
>Result is that node 1 downlist is selected, so it means that
>from node 2 point of view, node 1 was never down.
>
>Patch solves situation by adding additional check for largest
>previous membership.
>
>So current tests are:
>1) largest (previous #nodes - #nodes know to have left)
>2) (then) largest previous membership
>3) (and last as a tie-breaker) node with smallest nodeid
>
>Signed-off-by: Jan Friesse <jfriesse@redhat.com>
>---
> services/cpg.c |   17 +++++++++--------
> 1 files changed, 9 insertions(+), 8 deletions(-)
>
>diff --git a/services/cpg.c b/services/cpg.c
>index 7e62260..533f0c9 100644
>--- a/services/cpg.c
>+++ b/services/cpg.c
>@@ -816,16 +816,17 @@ static struct downlist_msg* downlist_master_choose (void)
> 		best_members = best->old_members - best->left_nodes;
> 		cmp_members = cmp->old_members - cmp->left_nodes;
> 
>-		if (cmp_members < best_members) {
>-			continue;
>-		}
>-		else if (cmp_members > best_members) {
>-			best = cmp;
>-		}
>-		else if (cmp->sender_nodeid < best->sender_nodeid) {
>+		if (cmp_members > best_members) {
> 			best = cmp;
>+		} else if (cmp_members == best_members) {
>+			if (cmp->old_members > best->old_members) {
>+				best = cmp;
>+			} else if (cmp->old_members == best->old_members) {
>+				if (cmp->sender_nodeid < best->sender_nodeid) {
>+					best = cmp;
>+				}
>+			}
> 		}
>-
> 	}
> 
> 	assert (best != NULL);
>-- 
>1.7.1
>

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Attachments on bug 830799: 591832 | 591833 | 591834 | 640856 | 640861 | 640862