trigger handshakes when lighthouse reply arrives (#246)

Currently, we wait until the next timer tick to act on the lighthouse's
reply to our HostQuery. This means we can easily add hundreds of
milliseconds of unnecessary delay to the handshake. To fix this, we
can introduce a channel to trigger an outbound handshake without waiting
for the next timer tick.

A few samples of cold ping time between two hosts that require a
lighthouse lookup:

    before (v1.2.0):

    time=156 ms
    time=252 ms
    time=12.6 ms
    time=301 ms
    time=352 ms
    time=49.4 ms
    time=150 ms
    time=13.5 ms
    time=8.24 ms
    time=161 ms
    time=355 ms

    after:

    time=3.53 ms
    time=3.14 ms
    time=3.08 ms
    time=3.92 ms
    time=7.78 ms
    time=3.59 ms
    time=3.07 ms
    time=3.22 ms
    time=3.12 ms
    time=3.08 ms
    time=8.04 ms

I recommend reviewing this PR by looking at each commit individually, as
some refactoring was required that makes the diff a bit confusing when
combined together.
This commit is contained in:
Wade Simmons
2020-07-22 10:35:10 -04:00
committed by GitHub
parent 4645e6034b
commit 4756c9613d
5 changed files with 169 additions and 66 deletions

View File

@ -103,6 +103,56 @@ func Test_NewHandshakeManagerVpnIP(t *testing.T) {
}
}
func Test_NewHandshakeManagerTrigger(t *testing.T) {
_, tuncidr, _ := net.ParseCIDR("172.1.1.1/24")
_, vpncidr, _ := net.ParseCIDR("172.1.1.1/24")
_, localrange, _ := net.ParseCIDR("10.1.1.1/24")
ip := ip2int(net.ParseIP("172.1.1.2"))
preferredRanges := []*net.IPNet{localrange}
mw := &mockEncWriter{}
mainHM := NewHostMap("test", vpncidr, preferredRanges)
lh := &LightHouse{}
blah := NewHandshakeManager(tuncidr, preferredRanges, mainHM, lh, &udpConn{}, defaultHandshakeConfig)
now := time.Now()
blah.NextOutboundHandshakeTimerTick(now, mw)
assert.Equal(t, 0, testCountTimerWheelEntries(blah.OutboundHandshakeTimer))
blah.AddVpnIP(ip)
assert.Equal(t, 1, testCountTimerWheelEntries(blah.OutboundHandshakeTimer))
// Trigger the same method the channel will
blah.handleOutbound(ip, mw, true)
// Make sure the trigger doesn't schedule another timer entry
assert.Equal(t, 1, testCountTimerWheelEntries(blah.OutboundHandshakeTimer))
hi := blah.pendingHostMap.Hosts[ip]
assert.Nil(t, hi.remote)
lh.addrMap = map[uint32][]udpAddr{
ip: {*NewUDPAddrFromString("10.1.1.1:4242")},
}
// This should trigger the hostmap to populate the hostinfo
blah.handleOutbound(ip, mw, true)
assert.NotNil(t, hi.remote)
assert.Equal(t, 1, testCountTimerWheelEntries(blah.OutboundHandshakeTimer))
}
func testCountTimerWheelEntries(tw *SystemTimerWheel) (c int) {
for _, i := range tw.wheel {
n := i.Head
for n != nil {
c++
n = n.Next
}
}
return c
}
func Test_NewHandshakeManagerVpnIPcleanup(t *testing.T) {
_, tuncidr, _ := net.ParseCIDR("172.1.1.1/24")
_, vpncidr, _ := net.ParseCIDR("172.1.1.1/24")