Sync watcher

[anarcher]

Github Issue

Fixes #734

Background

sebak node watcher mode watches it's validators and try to sync. with this mode, the node don't join consensus.

$sebak node -h  | grep watcher
      --watcher-mode                    watcher mode

t=2018-11-25T03:16:32+0900 lvl=info msg="genesis block already created" module=main height=1 round=0 confirmed=2018-11-24T18:14:29.582518000+09:00 total-txs=1 total-ops=2 proposer=
t=2018-11-25T03:16:32+0900 lvl=info msg="Starting Sebak" module=main caller=run.go:498
t=2018-11-25T03:16:32+0900 lvl=info msg="syncer config" module=sync node=GBVG.MAIO poolSize=300 fetchTimeout=1m0s retryInterval=10s checkInterval=30s checkPrevBlockInterval=30s caller=config.go:118
t=2018-11-25T03:16:32+0900 lvl=info msg="starting syncer" module=sync node=GBVG.MAIO submodule=syncer caller=syncer.go:89
t=2018-11-25T03:16:32+0900 lvl=info msg="starting sync watcher" module=sync node=GBVG.MAIO submodule=watcher height=3338 caller=watcher.go:89

t=2018-11-25T03:19:57+0900 lvl=info msg="watched sync height" module=sync node=GBVG.MAIO submodule=watcher high=3391 last=3391 caller=watcher.go:109
t=2018-11-25T03:19:57+0900 lvl=info msg="updated highest height" module=sync node=GBVG.MAIO submodule=syncer height=3391 nodes=1 caller=syncer.go:156
t=2018-11-25T03:19:57+0900 lvl=info msg="sync progress" module=sync node=GBVG.MAIO submodule=syncer start=3391 cur=3391 high=3391 caller=syncer.go:214
t=2018-11-25T03:19:57+0900 lvl=info msg="done sync work" module=sync node=GBVG.MAIO submodule=syncer height=3391 hash=8kyrw2QTqk2cA39wE7HEocUKYKLk9trmRwG78fXaPtpp caller=syncer.go:275
t=2018-11-25T03:20:02+0900 lvl=info msg="done highest height and nodes" module=sync node=GBVG.MAIO submodule=watcher height=3393 nodes=[GAYGELM74WJMKSLDN5YP2VAMP64WC4IXIGICUNK2SCVIT7KPTLY7M3MW] caller=watcher.go:142

Solution

• With watcher-mode, Node don't start InitRound. and start sync.Watcher.
• For reciving Txs, watcher node send tx to one of validators.

Possible Drawbacks

• A usecase of watcher mode, it can be stand-by validator. Same setting with --watcher-mode=1 can make standby validator. If active validator is down, we can change only --watcher-mode=0 for active validator. (maybe)

[codecov-io]

Codecov Report

Merging #814 into master will decrease coverage by 1.31%.
The diff coverage is 3.13%.

@@            Coverage Diff             @@
##           master     #814      +/-   ##
==========================================
- Coverage   61.97%   60.66%   -1.32%     
==========================================
  Files         151      152       +1     
  Lines        9913    10135     +222     
==========================================
+ Hits         6144     6148       +4     
- Misses       3109     3319     +210     
- Partials      660      668       +8

Flag	Coverage Δ
#integration_tests_long_term	44.52% <3.13%> (-1.16%)	⬇️
#integration_tests_node	40.31% <3.13%> (-0.71%)	⬇️
#unittests	50.13% <1.34%> (-1.17%)	⬇️

Impacted Files	Coverage Δ
lib/errors/errors.go	0% <ø> (ø)	⬆️
lib/node/runner/api_node.go	76.92% <ø> (ø)	⬆️
lib/common/config.go	100% <ø> (ø)	⬆️
lib/sync/watcher.go	0% <0%> (ø)
lib/node/runner/checker_message.go	55.43% <0%> (-20.69%)	⬇️
lib/node/node_state.go	80.76% <0%> (-14.69%)	⬇️
lib/node/local_node.go	87.01% <0%> (-2.33%)	⬇️
lib/sync/config.go	78.94% <0%> (-16.3%)	⬇️
lib/node/runner/node_runner.go	78.1% <33.33%> (-0.67%)	⬇️
cmd/sebak/cmd/run.go	65.06% <35.71%> (-0.93%)	⬇️
... and 7 more

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[spikeekips]

Super fast impl. 👍

[Charleslee522]

Some comments, I want to have more time for this :)

[anarcher]

Ping @Charleslee522 :-> Plz review it :->

[Charleslee522]

LGTM!