From 13d5ebb91361c001286dd3ca91481d98d75ed031 Mon Sep 17 00:00:00 2001 From: Andrew Rodland Date: Tue, 25 Oct 2016 12:49:45 -0400 Subject: [PATCH] MINOR: server: compute a "cumulative weight" to allow chash balancing to hit its target For active servers, this is the sum of the eweights of all active servers before this one in the backend, and [srv->cumulative_weight .. srv_cumulative_weight + srv_eweight) is a space occupied by this server in the range [0 .. lbprm.tot_wact), and likewise for backup servers with tot_wbck. This allows choosing a server or a range of servers proportional to their weight, by simple integer comparison. Signed-off-by: Andrew Rodland --- include/types/server.h | 1 + src/backend.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/types/server.h b/include/types/server.h index ce138206b..5d8921282 100644 --- a/include/types/server.h +++ b/include/types/server.h @@ -203,6 +203,7 @@ struct server { unsigned wscore; /* weight score, used during srv map computation */ unsigned prev_eweight; /* eweight before last change */ unsigned rweight; /* remainer of weight in the current LB tree */ + unsigned cumulative_weight; /* weight of servers prior to this one in the same group, for chash balancing */ unsigned npos, lpos; /* next and last positions in the LB tree */ struct eb32_node lb_node; /* node used for tree-based load balancing */ struct eb_root *lb_tree; /* we want to know in what tree the server is */ diff --git a/src/backend.c b/src/backend.c index faf872c0b..573f054dc 100644 --- a/src/backend.c +++ b/src/backend.c @@ -115,9 +115,11 @@ void recount_servers(struct proxy *px) !(px->options & PR_O_USE_ALL_BK)) px->lbprm.fbck = srv; px->srv_bck++; + srv->cumulative_weight = px->lbprm.tot_wbck; px->lbprm.tot_wbck += srv->eweight; } else { px->srv_act++; + srv->cumulative_weight = px->lbprm.tot_wact; px->lbprm.tot_wact += srv->eweight; } }