Hello, I would like to add a path to HAProxy. This patch is supposed to change how stats are handled for disabled proxies.
Prior to this patch, when outputting stats information, disabled proxies were ignored / skipped. This was an issue with old processes after a reload of HAProxy. It caused “the old process”, that was still holding active sessions, to not report stats any more. This made it impossible for any monitoring solution to figure out, how many currently active sessions exist. While this issue might barely be noticeable when using HAProxy for HTTP-Traffic, for long-running TCP-Sessions, this can become an issue. This patch will now not only check, if a proxy is disabled, but also if it still holds active sessions. And as long as it does, it will still output statistics. Initially I opened the following Issue on GitHub: https://github.com/haproxy/haproxy/issues/1307 The patch: From 0648fc0c148fe463ea9f0c77f34beeb484688eac Mon Sep 17 00:00:00 2001 From: Marno Krahmer <[email protected]> Date: Thu, 24 Jun 2021 16:51:08 +0200 Subject: [PATCH] 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. --- src/stats.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/src/stats.c b/src/stats.c index 3458924b7..a5620577a 100644 --- 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; } -- 2.17.0 Thanks a lot Marno
