So the assignment of proxies is based on the load. The number of clients
is ronded down to 8. Existing proxies that doesn't report the number
of clients will be distributed equaly to new proxies until they get 8
clients, that is okish as the existing proxies do have a maximum
capacity of 10.
Fixes#40048
Send the client poll request and response in a json-encoded format in
the HTTP request body rather than sending the data in HTTP headers. This
will pave the way for using domain-fronting alternatives for the
Snowflake rendezvous.
This change adds a prometheus exporter for our existing snowflake broker
metrics. Current values for the metrics can be fetched by sending a GET
request to /prometheus.
We currently don't sort the snowflake-ips metrics:
snowflake-ips CA=1,DE=1,AR=1,NL=1,FR=1,GB=2,US=4,CH=1
To facilitate eyeballing our metrics, this patch sorts snowflake-ips by
value. If the value is identical, we sort by string, i.e.:
snowflake-ips US=4,GB=2,AR=1,CA=1,CH=1,DE=1,FR=1,NL=1
This patch fixes tpo/anti-censorship/pluggable-transports/snowflake#40011
As we now partition proxies by NAT type, our stats are more useful if they
capture how many proxies of each type we have, and information on
whether we have enough proxies of the right NAT type for our clients.
This change adds proxy counts by NAT type and binned counts of denied clients by NAT type.
This will allow browser-based proxies that are unable to determine their
NAT type to conservatively label themselves as restricted NATs if they
fail to work with clients that have restricted NATs.
Now when proxies poll, they provide their NAT type to the broker. This
introduces a new snowflake heap of just restricted snowflakes that the
broker can pull from if the client has a known, unrestricted NAT. All
other clients will pull from a heap of snowflakes with unrestricted or
unknown NAT topologies.
We had some data races in the broker that occur when proxies and clients
modify the heap/snowflake map at the same time. This test has a client
and proxy access the broker simultaneously to check for data races.
Proxies now include information about what type they are when they poll
for client offers. The broker saves this information along with
snowflake ids and outputs it on the /debug page.
Switch to containing all communication between the proxy and the broker
in the HTTP response body. This will make things easier if we ever use
something other than HTTP communicate between different actors in the
snowflake system.
Other changes to the protocol are as follows:
- requests are accompanied by a version number so the broker can be
backwards compatable if desired in the future
- all responses are 200 OK unless the request was badly formatted
