From: Willy Tarreau <w@1wt.eu>
Date: Tue, 22 Jun 2021 15:31:51 +0000 (+0200)
Subject: CLEANUP: backend: remove impossible case of round-robin + consistent hash
X-Git-Tag: v2.5-dev1~47
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ffb045ed12f14a0367bcb0aa39931806c84357a;p=thirdparty%2Fhaproxy.git

CLEANUP: backend: remove impossible case of round-robin + consistent hash

In 1.4, consistent hashing was brought by commit 6b2e11be1 ("[MEDIUM]
backend: implement consistent hashing variation") which took care of
replacing all direct calls to map_get_server_rr() with an alternate
call to chash_get_next_server() if consistent hash was being used.

One of them, however, cannot happen because a preliminary test for
static round-robin is being done prior to the call, so we're certain
that if it matches it cannot use a consistent hash tree.

Let's remove it.
---

diff --git a/src/backend.c b/src/backend.c
index 2041c430e2..f5fec1d8ad 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -679,10 +679,9 @@ int assign_server(struct stream *s)
 		case BE_LB_LKUP_CHTREE:
 		case BE_LB_LKUP_MAP:
 			if ((s->be->lbprm.algo & BE_LB_KIND) == BE_LB_KIND_RR) {
+				/* static-rr (map) or random (chash) */
 				if ((s->be->lbprm.algo & BE_LB_PARM) == BE_LB_RR_RANDOM)
 					srv = get_server_rnd(s, prev_srv);
-				else if ((s->be->lbprm.algo & BE_LB_LKUP) == BE_LB_LKUP_CHTREE)
-					srv = chash_get_next_server(s->be, prev_srv);
 				else
 					srv = map_get_server_rr(s->be, prev_srv);
 				break;