Updated memberlist to fix negative RTT measurements.

Fixes #3704

CHANGELOG.md

@@ -6,6 +6,8 @@ IMPROVEMENTS:
 
 BUG FIXES:
 
+* agent: Updated memberlist to pull in a fix for negative RTT measurements and their associated log messages about rejected coordinates. [[GH-3704](https://github.com/hashicorp/consul/issues/3704)]
+
 ## 1.0.1 (November 20, 2017)
 
 FEATURES:

vendor/github.com/hashicorp/memberlist/state.go

@@ -251,10 +251,17 @@ func (m *Memberlist) probeNode(node *nodeState) {
 	nackCh := make(chan struct{}, m.config.IndirectChecks+1)
 	m.setProbeChannels(ping.SeqNo, ackCh, nackCh, probeInterval)
 
+	// Mark the sent time here, which should be after any pre-processing but
+	// before system calls to do the actual send. This probably over-reports
+	// a bit, but it's the best we can do. We had originally put this right
+	// after the I/O, but that would sometimes give negative RTT measurements
+	// which was not desirable.
+	sent := time.Now()
+
 	// Send a ping to the node. If this node looks like it's suspect or dead,
 	// also tack on a suspect message so that it has a chance to refute as
 	// soon as possible.
-	deadline := time.Now().Add(probeInterval)
+	deadline := sent.Add(probeInterval)
 	addr := node.Address()
 	if node.State == stateAlive {
 		if err := m.encodeAndSendMsg(addr, pingMsg, &ping); err != nil {
@@ -284,11 +291,6 @@ func (m *Memberlist) probeNode(node *nodeState) {
 		}
 	}
 
-	// Mark the sent time here, which should be after any pre-processing and
-	// system calls to do the actual send. This probably under-reports a bit,
-	// but it's the best we can do.
-	sent := time.Now()
-
 	// Arrange for our self-awareness to get updated. At this point we've
 	// sent the ping, so any return statement means the probe succeeded
 	// which will improve our health until we get to the failure scenarios

vendor/github.com/hashicorp/memberlist/transport.go

@@ -17,7 +17,7 @@ type Packet struct {
 
 	// Timestamp is the time when the packet was received. This should be
 	// taken as close as possible to the actual receipt time to help make an
-	// accurate RTT measurements during probes.
+	// accurate RTT measurement during probes.
 	Timestamp time.Time
 }
 

vendor/vendor.json

@@ -59,7 +59,7 @@
 		{"path":"github.com/hashicorp/hil","checksumSHA1":"kqCMCHy2b+RBMKC+ER+OPqp8C3E=","revision":"1e86c6b523c55d1fa6c6e930ce80b548664c95c2","revisionTime":"2016-07-11T23:18:37Z"},
 		{"path":"github.com/hashicorp/hil/ast","checksumSHA1":"UICubs001+Q4MsUf9zl2vcMzWQQ=","revision":"1e86c6b523c55d1fa6c6e930ce80b548664c95c2","revisionTime":"2016-07-11T23:18:37Z"},
 		{"path":"github.com/hashicorp/logutils","checksumSHA1":"vt+P9D2yWDO3gdvdgCzwqunlhxU=","revision":"0dc08b1671f34c4250ce212759ebd880f743d883","revisionTime":"2015-06-09T07:04:31Z"},
-		{"path":"github.com/hashicorp/memberlist","checksumSHA1":"W1MrXPyP9I630SENN7b9Vn/K5r0=","revision":"caa5d20d6a642b7543b3745e54031a96008bee57","revisionTime":"2017-11-10T01:18:39Z"},
+		{"path":"github.com/hashicorp/memberlist","checksumSHA1":"88DoUaWD6hS1KTt57RMQ7wxHu/k=","revision":"9bdd37bfb26bd039c08b0f36be6f80ceede4aaf3","revisionTime":"2017-11-17T04:34:18Z"},
 		{"path":"github.com/hashicorp/net-rpc-msgpackrpc","checksumSHA1":"qnlqWJYV81ENr61SZk9c65R1mDo=","revision":"a14192a58a694c123d8fe5481d4a4727d6ae82f3","revisionTime":"2015-11-16T02:03:38Z"},
 		{"path":"github.com/hashicorp/raft","checksumSHA1":"JjJtGJi1ywWhVhs/PvTXxe4TeD8=","revision":"6d14f0c70869faabd9e60ba7ed88a6cbbd6a661f","revisionTime":"2017-10-03T22:09:13Z","version":"v1.0.0","versionExact":"v1.0.0"},
 		{"path":"github.com/hashicorp/raft-boltdb","checksumSHA1":"QAxukkv54/iIvLfsUP6IK4R0m/A=","revision":"d1e82c1ec3f15ee991f7cc7ffd5b67ff6f5bbaee","revisionTime":"2015-02-01T20:08:39Z"},