From d72822442d1f394ea85d9d22cf591e586e0e4b37 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Mon, 4 Jun 2012 00:22:44 +0200
Subject: [PATCH] MEDIUM: stats: add support for soft stop/soft start in the
 admin interface

One important missing feature on the web interface is the ability to perform
a soft stop/soft start. This is now possible.
---
 include/types/proto_http.h |  2 ++
 src/dumpstats.c            |  2 ++
 src/proto_http.c           | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index a287c35822..3457a2a381 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -262,6 +262,8 @@ enum {
 	ST_ADM_ACTION_NONE = 0,
 	ST_ADM_ACTION_DISABLE,
 	ST_ADM_ACTION_ENABLE,
+	ST_ADM_ACTION_STOP,
+	ST_ADM_ACTION_START,
 };
 
 /* status codes available for the stats admin page */
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 14d50e1c67..a01c6ed0de 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -3171,6 +3171,8 @@ static int stats_dump_proxy(struct stream_interface *si, struct proxy *px, struc
 					"<option value=\"\"></option>"
 					"<option value=\"disable\">Disable</option>"
 					"<option value=\"enable\">Enable</option>"
+					"<option value=\"stop\">Soft Stop</option>"
+					"<option value=\"start\">Soft Start</option>"
 					"</select>"
 					"<input type=\"hidden\" name=\"b\" value=\"#%d\">"
 					"&nbsp;<input type=\"submit\" value=\"Apply\">"
diff --git a/src/proto_http.c b/src/proto_http.c
index 7eeb4f64a2..c0a66879fc 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -2605,6 +2605,12 @@ int http_process_req_stat_post(struct stream_interface *si, struct http_txn *txn
 				else if (strcmp(value, "enable") == 0) {
 					action = ST_ADM_ACTION_ENABLE;
 				}
+				else if (strcmp(value, "stop") == 0) {
+					action = ST_ADM_ACTION_STOP;
+				}
+				else if (strcmp(value, "start") == 0) {
+					action = ST_ADM_ACTION_START;
+				}
 				else {
 					si->applet.ctx.stats.st_code = STAT_STATUS_ERRP;
 					goto out;
@@ -2642,6 +2648,38 @@ int http_process_req_stat_post(struct stream_interface *si, struct http_txn *txn
 							total_servers++;
 						}
 						break;
+					case ST_ADM_ACTION_STOP:
+					case ST_ADM_ACTION_START:
+						if (action == ST_ADM_ACTION_START)
+							sv->uweight = sv->iweight;
+						else
+							sv->uweight = 0;
+
+						if (px->lbprm.algo & BE_LB_PROP_DYN) {
+							/* we must take care of not pushing the server to full throttle during slow starts */
+							if ((sv->state & SRV_WARMINGUP) && (px->lbprm.algo & BE_LB_PROP_DYN))
+								sv->eweight = (BE_WEIGHT_SCALE * (now.tv_sec - sv->last_change) + sv->slowstart - 1) / sv->slowstart;
+							else
+								sv->eweight = BE_WEIGHT_SCALE;
+							sv->eweight *= sv->uweight;
+						} else {
+							sv->eweight = sv->uweight;
+						}
+
+						/* static LB algorithms are a bit harder to update */
+						if (px->lbprm.update_server_eweight)
+							px->lbprm.update_server_eweight(sv);
+						else if (sv->eweight) {
+							if (px->lbprm.set_server_status_up)
+								px->lbprm.set_server_status_up(sv);
+						}
+						else {
+							if (px->lbprm.set_server_status_down)
+								px->lbprm.set_server_status_down(sv);
+						}
+						altered_servers++;
+						total_servers++;
+						break;
 					}
 				} else {
 					/* the server name is unknown or ambiguous (duplicate names) */
-- 
2.47.3