From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 25 Mar 2019 16:11:22 +0000 (+0100)
Subject: dnsdist: Downstream failures only count for fresh TCP connections
X-Git-Tag: dnsdist-1.4.0-alpha1~25^2~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c53fb6b23ad801f51c92bb0cece6ce5ec184aca2;p=thirdparty%2Fpdns.git

dnsdist: Downstream failures only count for fresh TCP connections
---

diff --git a/pdns/dnsdist-tcp.cc b/pdns/dnsdist-tcp.cc
index 6a580a05ca..f6f59b5abb 100644
--- a/pdns/dnsdist-tcp.cc
+++ b/pdns/dnsdist-tcp.cc
@@ -880,12 +880,15 @@ static void handleDownstreamIOCallback(int fd, FDMultiplexer::funcparam_t& param
        Let's just drop the connection
     */
     vinfolog("Got an exception while handling (%s backend) TCP query from %s: %s", (state->d_lastIOState == IOState::NeedRead ? "reading from" : "writing to"), state->d_ci.remote.toStringWithPort(), e.what());
-    /* remove this FD from the IO multiplexer */
-    ++state->d_downstreamFailures;
+    /* don't increase this counter when reusing connections */
+    if (state->d_freshDownstreamConnection) {
+      ++state->d_downstreamFailures;
+    }
     if (state->d_outstanding && state->d_ds != nullptr) {
       --state->d_ds->outstanding;
       state->d_outstanding = false;
     }
+    /* remove this FD from the IO multiplexer */
     iostate = IOState::Done;
     connectionDied = true;
   }