On 06/13/2017 09:16 PM, Frederic Lecaille wrote:
Hello Patrick,
[snipped]
I hope the pach attached to this mail will definitively fix such peer CLOSE_WAIT issues.
A better patch which fixes the comments and commit message.
>From 5535bcd5298bbbce11385eee18ef740848d31903 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20L=C3=A9caille?= <flecai...@haproxy.com> Date: Tue, 13 Jun 2017 16:39:57 +0200 Subject: [PATCH] MINOR: peers: Peers CLOSE_WAIT issue. A peer session which has just been created upon reconnect timeout expirations, could be right after shutdown (at peer session level) because the remote side peer could also righ after have connected. In such a case the underlying TCP session was still running (connect()/accept()) and finally left in CLOSE_WAIT state after the remote side stopped writting (shutdown(SHUT_WR)). Now on, with this patch we never shutdown such peer sessions wich have just been created. We leave them connect to the remote peer which is already connected and must shutdown its own peer session. Thanks to Patric Hemmer for reporting this issue and to Willy and Yelp blogs which helped me in fixing this issue. (See https://www.haproxy.com/blog/truly-seamless-reloads-with-haproxy-no-more-hacks/ and https://engineeringblog.yelp.com/2015/04/true-zero-downtime-haproxy-reloads.htmll) --- src/peers.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/peers.c b/src/peers.c index 0c8861f..0dd93ea 100644 --- a/src/peers.c +++ b/src/peers.c @@ -1719,7 +1719,13 @@ static void peer_session_forceshutdown(struct appctx *appctx) { struct peer *ps; - if (!appctx) + /* Note that the peer sessions which have just been created + * (->st0 == PEER_SESS_SC_CONNECTCODE) must not + * be shutdown, if not, the TCP session will never be closed + * and stay in CLOSE_WAIT state after having been closed by + * the remote side. + */ + if (!appctx || appctx->st0 == PEER_SESS_SC_CONNECTCODE) return; if (appctx->applet != &peer_applet) -- 2.1.4
