* add calculated_remotes
This setting allows us to "guess" what the remote might be for a host
while we wait for the lighthouse response. For networks that hard
designed with in mind, it can help speed up handshake performance, as well as
improve resiliency in the case that all lighthouses are down.
Example:
lighthouse:
# ...
calculated_remotes:
# For any Nebula IPs in 10.0.10.0/24, this will apply the mask and add
# the calculated IP as an initial remote (while we wait for the response
# from the lighthouse). Both CIDRs must have the same mask size.
# For example, Nebula IP 10.0.10.123 will have a calculated remote of
# 192.168.1.123
10.0.10.0/24:
- mask: 192.168.1.0/24
port: 4242
* figure out what is up with this test
* add test
* better logic for sending handshakes
Keep track of the last light of hosts we sent handshakes to. Only log
handshake sent messages if the list has changed.
Remove the test Test_NewHandshakeManagerTrigger because it is faulty and
makes no sense. It relys on the fact that no handshake packets actually
get sent, but with these changes we would send packets now (which it
should!)
* use atomic.Pointer
* cleanup to make it clearer
* fix typo in example
These new helpers make the code a lot cleaner. I confirmed that the
simple helpers like `atomic.Int64` don't add any extra overhead as they
get inlined by the compiler. `atomic.Pointer` adds an extra method call
as it no longer gets inlined, but we aren't using these on the hot path
so it is probably okay.
We have a few small race conditions with creating the HostInfo.ConnectionState
since we add the host info to the pendingHostMap before we set this
field. We can make everything a lot easier if we just add an "init"
function so that we can set this field in the hostinfo before we add it
to the hostmap.
There are some subtle race conditions with the previous handshake_ix implementation, mostly around collisions with localIndexId. This change refactors it so that we have a "commit" phase during the handshake where we grab the lock for the hostmap and ensure that we have a unique local index before storing it. We also now avoid using the pending hostmap at all for receiving stage1 packets, since we have everything we need to just store the completed handshake.
Co-authored-by: Nate Brown <nbrown.us@gmail.com>
Co-authored-by: Ryan Huber <rhuber@gmail.com>
Co-authored-by: forfuncsake <drussell@slack-corp.com>
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 change exposes the current constants we have defined for the handshake
manager as configuration options. This will allow us to test and tweak
with different intervals and wait rotations.
# Handshake Manger Settings
handshakes:
# Total time to try a handshake = sequence of `try_interval * retries`
# With 100ms interval and 20 retries it is 23.5 seconds
try_interval: 100ms
retries: 20
# wait_rotation is the number of handshake attempts to do before starting to try non-local IP addresses
wait_rotation: 5
Nate Brown