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.
---
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 ce13820..5d89212 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 faf872c..573f054 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;
}
}
--
2.9.3
