syncthing/cmd
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00
..
stbench all: Fix comment typos 2017-11-04 07:20:11 +00:00
stcli all: Convert folders to use filesystem abstraction 2017-08-19 14:36:56 +00:00
stcompdirs lib: Folder marker is now a folder 2017-09-02 05:52:38 +00:00
stdisco all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
stdiscosrv cmd/stdiscosrv: New discovery server (fixes #4618) 2018-01-14 08:52:31 +00:00
stevents all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
stfileinfo lib/fs, lib/model, lib/scanner: Make scans cancellable (fixes #3965) 2017-04-26 00:15:23 +00:00
stfinddevice all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
stgenfiles all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
stindex all: Convert folders to use filesystem abstraction 2017-08-19 14:36:56 +00:00
strelaypoolsrv gui: HTML accessibility updates 2017-07-15 09:54:37 +00:00
strelaysrv all: Fix comment typos 2017-11-04 07:20:11 +00:00
stsigtool cmd/stsigtool: Silence spurious Go 1.10 test/vet complaint 2017-12-10 19:42:17 +01:00
stvanity all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
stwatchfile all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
syncthing cmd/syncthing: UI for version restoration (fixes #2599) (#4602) 2018-01-01 15:39:23 +01:00
todos all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
.gitignore Remove reprecated st* utils 2014-07-01 12:20:25 +02:00