MEDIUM: stats: include disabled proxies that hold active sessions to stats

After reloading HAProxy, the old process may still hold active sessions.
Currently there is no way to gather information, how many sessions such
a process still holds. This patch will not exclude disabled proxies from
stats output when they hold at least one active session. This will allow
sending `!@<PID> show stat` through a master socket to the disabled
process and have it returning its stats data.

diff --git a/src/stats.c b/src/stats.c
index 3458924b786fef8546cc155822635c3db723bf7a..4b4f28daf2264fc2c52cf16a08f66b7b037cbe45 100644 (file)
--- a/src/stats.c
+++ b/src/stats.c
@@ -3575,8 +3575,11 @@ static int stats_dump_proxies(struct stream_interface *si,
                }
 
                px = appctx->ctx.stats.obj1;
-               /* skip the disabled proxies, global frontend and non-networked ones */
-               if (!px->disabled && px->uuid > 0 && (px->cap & (PR_CAP_FE | PR_CAP_BE))) {
+               /* Skip the global frontend proxies and non-networked ones.
+                * Also skip disabled proxies unless they are still holding active sessions.
+                * This change allows retrieving stats from "old" proxies after a reload.
+                */
+               if ((!px->disabled || px->served > 0) && px->uuid > 0 && (px->cap & (PR_CAP_FE | PR_CAP_BE))) {
                        if (stats_dump_proxy_to_buffer(si, htx, px, uri) == 0)
                                return 0;
                }