Fix #3868 (comment)

Commits:

* mempool: make `max_tx_bytes` configurable instead of `max_msg_bytes`

* update CHANGELOG_PENDING

* apply suggestions from code review

* mempool: make max_msg_bytes configurable

* apply suggestions from code review

* update changelog pending

* apply suggestions from code review again

## Description

Refs #2659

Breaking changes in the mempool package:

[mempool] #2659 Mempool now an interface
    old Mempool renamed to CListMempool
    NewMempool renamed to NewCListMempool
    Option renamed to CListOption
    MempoolReactor renamed to Reactor
    NewMempoolReactor renamed to NewReactor
    unexpose TxID method
    TxInfo.PeerID renamed to SenderID
    unexpose MempoolReactor.Mempool

Breaking changes in the state package:

[state] #2659 Mempool interface moved to mempool package
    MockMempool moved to top-level mock package and renamed to Mempool

Non Breaking changes in the node package:

[node] #2659 Add Mempool method, which allows you to access mempool

## Commits

* move Mempool interface into mempool package

Refs #2659

Breaking changes in the mempool package:

- Mempool now an interface
- old Mempool renamed to CListMempool

Breaking changes to state package:

- MockMempool moved to mempool/mock package and renamed to Mempool
- Mempool interface moved to mempool package

* assert CListMempool impl Mempool

* gofmt code

* rename MempoolReactor to Reactor

- combine everything into one interface
- rename TxInfo.PeerID to TxInfo.SenderID
- unexpose MempoolReactor.Mempool

* move mempool mock into top-level mock package

* add a fixme

TxsFront should not be a part of the Mempool interface
because it leaks implementation details. Instead, we need to come up
with general interface for querying the mempool so the MempoolReactor
can fetch and broadcast txs to peers.

* change node#Mempool to return interface

* save commit = new reactor arch

* Revert "save commit = new reactor arch"

This reverts commit 1bfceacd9d.

* require CListMempool in mempool.Reactor

* add two changelog entries

* fixes after my own review

* quote interfaces, structs and functions

* fixes after Ismail's review

* make node's mempool an interface

* make InitWAL/CloseWAL methods a part of Mempool interface

* fix merge conflicts

* make node's mempool an interface

* mempool: add a safety check, write tests for mempoolIDs

and document 65536 limit in the mempool reactor spec

follow-up to https://github.com/tendermint/tendermint/pull/2778

* rename the test

* fixes after Ismail's review

Refs #3306, irisnet@fdbb676

I ran an irishub validator. After the validator node ran several days, I dump the whole goroutine stack. I found that there were hundreds of broadcastTxRoutine. However, the connected peer quantity was less than 30. So I belive that there must be broadcastTxRoutine leakage issue.

According to my analysis, I think the root cause of this issue locate in below code:

		select {
		case <-next.NextWaitChan():
			// see the start of the for loop for nil check
			next = next.Next()
		case <-peer.Quit():
			return
		case <-memR.Quit():
			return
		}

As we know, if multiple paths are avaliable in the same time, then a random path will be selected. Suppose that next.NextWaitChan() and peer.Quit() are both avaliable, and next.NextWaitChan() is chosen.

                // send memTx
		msg := &TxMessage{Tx: memTx.tx}
		success := peer.Send(MempoolChannel, cdc.MustMarshalBinaryBare(msg))
		if !success {
			time.Sleep(peerCatchupSleepIntervalMS * time.Millisecond)
			continue
		}

Then next will be non-empty and the peer send operation won't be success. As a result, this go routine will be track into infinite loop and won't be released.

My proposal is to check peer.Quit() and memR.Quit() in every loop no matter whether next is nil.

Closes #1798

This is done by making every mempool tx maintain a list of peers who its received the tx from. Instead of using the 20byte peer ID, it instead uses a local map from peerID to uint16 counter, so every peer adds 2 bytes. (Word aligned to probably make it 8 bytes)

This also required resetting the callback function on every CheckTx. This likely has performance ramifications for instruction caching. The actual setting operation isn't costly with the removal of defers in this PR.

* Make the mempool not gossip txs back to peers its received it from

* Fix adversarial memleak

* Don't break interface

* Update changelog

* Forgot to add a mtx

* forgot a mutex

* Update mempool/reactor.go

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Update mempool/mempool.go

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Use unknown peer ID

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* fix compilation

* use next wait chan logic when skipping

* Minor fixes

* Add TxInfo

* Add reverse map

* Make activeID's auto-reserve 0

* 0 -> UnknownPeerID

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Switch to making the normal case set a callback on the reqres object

The recheck case is still done via the global callback, and stats
are also set via global callback

* fix merge conflict

* Addres comments

* Add cache tests

* add cache tests

* minor fixes

* update metrics in reqResCb and reformat code

* goimport -w mempool/reactor.go

* mempool: update memTx senders

I had to introduce txsMap for quick mempoolTx lookups.

* change senders type from []uint16 to sync.Map

Fixes DATA RACE:

```
Read at 0x00c0013fcd3a by goroutine 183:
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).broadcastTxRoutine()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:195 +0x3c7

Previous write at 0x00c0013fcd3a by D[2019-02-27|10:10:49.058] Read PacketMsg                               switch=3 peer=35bc1e3558c182927b31987eeff3feb3d58a0fc5@127.0.0.1
:46552 conn=MConn{pipe} packet="PacketMsg{30:2B06579D0A143EB78F3D3299DE8213A51D4E11FB05ACE4D6A14F T:1}"
goroutine 190:
  github.com/tendermint/tendermint/mempool.(*Mempool).CheckTxWithInfo()
      /go/src/github.com/tendermint/tendermint/mempool/mempool.go:387 +0xdc1
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).Receive()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:134 +0xb04
  github.com/tendermint/tendermint/p2p.createMConnection.func1()
      /go/src/github.com/tendermint/tendermint/p2p/peer.go:374 +0x25b
  github.com/tendermint/tendermint/p2p/conn.(*MConnection).recvRoutine()
      /go/src/github.com/tendermint/tendermint/p2p/conn/connection.go:599 +0xcce

Goroutine 183 (running) created at:
D[2019-02-27|10:10:49.058] Send                                         switch=2 peer=1efafad5443abeea4b7a8155218e4369525d987e@127.0.0.1:46193 channel=48 conn=MConn{pipe} m
sgBytes=2B06579D0A146194480ADAE00C2836ED7125FEE65C1D9DD51049
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).AddPeer()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:105 +0x1b1
  github.com/tendermint/tendermint/p2p.(*Switch).startInitPeer()
      /go/src/github.com/tendermint/tendermint/p2p/switch.go:683 +0x13b
  github.com/tendermint/tendermint/p2p.(*Switch).addPeer()
      /go/src/github.com/tendermint/tendermint/p2p/switch.go:650 +0x585
  github.com/tendermint/tendermint/p2p.(*Switch).addPeerWithConnection()
      /go/src/github.com/tendermint/tendermint/p2p/test_util.go:145 +0x939
  github.com/tendermint/tendermint/p2p.Connect2Switches.func2()
      /go/src/github.com/tendermint/tendermint/p2p/test_util.go:109 +0x50

I[2019-02-27|10:10:49.058] Added good transaction                       validator=0 tx=43B4D1F0F03460BD262835C4AA560DB860CFBBE85BD02386D83DAC38C67B3AD7 res="&{CheckTx:gas_w
anted:1 }" height=0 total=375
Goroutine 190 (running) created at:
  github.com/tendermint/tendermint/p2p/conn.(*MConnection).OnStart()
      /go/src/github.com/tendermint/tendermint/p2p/conn/connection.go:210 +0x313
  github.com/tendermint/tendermint/libs/common.(*BaseService).Start()
      /go/src/github.com/tendermint/tendermint/libs/common/service.go:139 +0x4df
  github.com/tendermint/tendermint/p2p.(*peer).OnStart()
      /go/src/github.com/tendermint/tendermint/p2p/peer.go:179 +0x56
  github.com/tendermint/tendermint/libs/common.(*BaseService).Start()
      /go/src/github.com/tendermint/tendermint/libs/common/service.go:139 +0x4df
  github.com/tendermint/tendermint/p2p.(*peer).Start()
      <autogenerated>:1 +0x43
  github.com/tendermint/tendermint/p2p.(*Switch).startInitPeer()
```

* explain the choice of a map DS for senders

* extract ids pool/mapper to a separate struct

* fix literal copies lock value from senders: sync.Map contains sync.Mutex

* use sync.Map#LoadOrStore instead of Load

* fixes after Ismail's review

* rename resCbNormal to resCbFirstTime

- fixes #3008
- reactor requires encoded messages are less than maxMsgSize
- requires size of tx + amino-overhead to not exceed maxMsgSize

* use READ lock/unlock in ConsensusState#GetLastHeight

Refs #2721

* do not use defers when there's no need

* fix peer formatting (output its address instead of the pointer)

```
[54310]: E[11-02|11:59:39.851] Connection failed @ sendRoutine              module=p2p peer=0xb78f00 conn=MConn{74.207.236.148:26656} err="pong timeout"
```

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435326581

* panic if peer has no state

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435347165

It's confusing that sometimes we check if peer has a state, but most of
the times we expect it to be there

1. add79700b5/mempool/reactor.go (L138)
2. add79700b5/rpc/core/consensus.go (L196) (edited)

I will change everything to always assume peer has a state and panic
otherwise

that should help identify issues earlier

* abci/localclient: extend lock on app callback

App callback should be protected by lock as well (note this was already
done for InitChainAsync, why not for others???). Otherwise, when we
execute the block, tx might come in and call the callback in the same
time we're updating it in execBlockOnProxyApp => DATA RACE

Fixes #2721

Consensus state is locked

```
goroutine 113333 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00180009c, 0xc0000c7e00)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*RWMutex).RLock(0xc001800090)
        /usr/local/go/src/sync/rwmutex.go:50 +0x4e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).GetRoundState(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:218 +0x46
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).queryMaj23Routine(0xc0017def80, 0x11104a0, 0xc0072488f0, 0xc007248
9c0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:735 +0x16d
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).AddPeer
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:172 +0x236
```

because localClient is locked

```
goroutine 1899 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0xc0000cb500)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).SetResponseCallback(0xc0001fb560, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:32 +0x33
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnConsensus).SetResponseCallback(0xc00002f750, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:57 +0x40
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.execBlockOnProxyApp(0x1104e20, 0xc002ca0ba0, 0x11092a0, 0xc00002f750, 0xc0001fe960, 0xc000bfc660, 0x110cfe0, 0xc000090330, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:230 +0x1fd
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.(*BlockExecutor).ApplyBlock(0xc002c2a230, 0x7, 0x0, 0xc000eae880, 0x6, 0xc002e52c60, 0x16, 0x1f927, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:96 +0x142
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).finalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1339 +0xa3e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryFinalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1270 +0x451
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit.func1(0xc001800000, 0x0, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1218 +0x90
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit(0xc001800000, 0x1f928, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1247 +0x6b8
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).addVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xc003bc7ad0, 0xc003bc7b10)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1659 +0xbad
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryAddVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xf1, 0xf1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1517 +0x59
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).handleMsg(0xc001800000, 0xd98200, 0xc0070dbed0, 0xc000cf4cc0, 0x28)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:660 +0x64b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).receiveRoutine(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:617 +0x670
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).OnStart
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:311 +0x132
```

tx comes in and CheckTx is executed right when we execute the block

```
goroutine 111044 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0x0)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).CheckTxAsync(0xc0001fb0e0, 0xc002d94500, 0x13f, 0x280, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:85 +0x47
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnMempool).CheckTxAsync(0xc00002f720, 0xc002d94500, 0x13f, 0x280, 0x1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:114 +0x51
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool.(*Mempool).CheckTx(0xc002d3a320, 0xc002d94500, 0x13f, 0x280, 0xc0072355f0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool/mempool.go:316 +0x17b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core.BroadcastTxSync(0xc002d94500, 0x13f, 0x280, 0x0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core/mempool.go:93 +0xb8
reflect.Value.call(0xd85560, 0x10326c0, 0x13, 0xec7b8b, 0x4, 0xc00663f180, 0x1, 0x1, 0xc00663f180, 0xc00663f188, ...)
        /usr/local/go/src/reflect/value.go:447 +0x449
reflect.Value.Call(0xd85560, 0x10326c0, 0x13, 0xc00663f180, 0x1, 0x1, 0x0, 0x0, 0xc005cc9344)
        /usr/local/go/src/reflect/value.go:308 +0xa4
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.makeHTTPHandler.func2(0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/handlers.go:269 +0x188
net/http.HandlerFunc.ServeHTTP(0xc002c81f20, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.(*ServeMux).ServeHTTP(0xc002c81b60, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2361 +0x127
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.maxBytesHandler.ServeHTTP(0x10f8a40, 0xc002c81b60, 0xf4240, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:219 +0xcf
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.RecoverAndLogHandler.func1(0x1103220, 0xc00121e620, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:192 +0x394
net/http.HandlerFunc.ServeHTTP(0xc002c06ea0, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.serverHandler.ServeHTTP(0xc001a1aa90, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2741 +0xab
net/http.(*conn).serve(0xc00785a3c0, 0x11041a0, 0xc000f844c0)
        /usr/local/go/src/net/http/server.go:1847 +0x646
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2851 +0x2f5
```

* consensus: use read lock in Receive#VoteMessage

* use defer to unlock mutex because application might panic

* use defer in every method of the localClient

* add a changelog entry

* drain channels before Unsubscribe(All)

Read 55362ed766/libs/pubsub/pubsub.go (L13)
for the detailed explanation of the issue.

We'll need to fix it someday. Make sure to keep an eye on
https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-033-pubsub.md

* retry instead of panic when peer has no state in reactors other than consensus

in /dump_consensus_state RPC endpoint, skip a peer with no state

* rpc/core/mempool: simplify error messages

* rpc/core/mempool: use time.After instead of timer

also, do not log DeliverTx result (to be consistent with other memthods)

* unlock before calling the callback in reqRes#SetCallback

This reverts commit d02c5d1e30.

Refs #646

Fixes #1762#issuecomment-398940107

This reverts commit 96a3502

to better handle zero cache size

* updateToState exits early if the state isn't new, which happens after
* fast syncing. This results in not sending a NewRoundStep message. The mempool
* reactor depends on PeerState, which is updated by NewRoundStep
* messages. If the peer never sends a NewRoundStep, the mempool reactor
* will think they're behind, and never forward transactions. Note this
* only happens when `create_empty_blocks = false`, because otherwise
* peers will move through the consensus state and send a NewRoundStep
* for a new step soon anyways. Simple fix is just to send the
* NewRoundStep message during updateToState even if exit early

1. remove pointer
2. add Quit() method to Service interface

https://play.golang.org/p/gN21yO9IRs3

```
func waitWithCancel(f func() *clist.CElement, ctx context.Context) *clist.CElement {
	el := make(chan *clist.CElement, 1)
	select {
	case el <- f():
```
will just run f() blockingly, so this doesn't change much in terms of behavior.

Leaking goroutine:
```
114 @ 0x42f2bc 0x42f3ae 0x440794 0x4403b9 0x468002 0x9fe32d 0x9ff78f 0xa025ed 0x45e571
```

Explanation:
it blocks on an empty clist forever. so unless theres txs coming in,
this go routine will just sit there, holding onto the peer too.
if we're constantly reconnecting to some peer, old instances are not
garbage collected, leading to memory leak.

Fixes https://github.com/cosmos/gaia/issues/108
Previous attempt https://github.com/tendermint/tendermint/pull/1156

uint64 is considered dangerous. the details will follow in a blog post.

comment out failing consensus tests for now

rewrite rpc httpclient to use new pubsub package

import pubsub as tmpubsub, query as tmquery

make event IDs constants
EventKey -> EventTypeKey

rename EventsPubsub to PubSub

mempool does not use pubsub

rename eventsSub to pubsub

new subscribe API

fix channel size issues and consensus tests bugs

refactor rpc client

add missing discardFromChan method

add mutex

rename pubsub to eventBus

remove IsRunning from WSRPCConnection interface (not needed)

add a comment in broadcastNewRoundStepsAndVotes

rename registerEventCallbacks to broadcastNewRoundStepsAndVotes

See https://dave.cheney.net/2014/03/19/channel-axioms

stop eventBuses after reactor tests

remove unnecessary Unsubscribe

return subscribe helper function

move discardFromChan to where it is used

subscribe now returns an err

this gives us ability to refuse to subscribe if pubsub is at its max
capacity.

use context for control overflow

cache queries

handle err when subscribing in replay_test

rename testClientID to testSubscriber

extract var

set channel buffer capacity to 1 in replay_file

fix byzantine_test

unsubscribe from single event, not all events

refactor httpclient to return events to appropriate channels

return failing testReplayCrashBeforeWriteVote test

fix TestValidatorSetChanges

refactor code a bit

fix testReplayCrashBeforeWriteVote

add comment

fix TestValidatorSetChanges

fixes from Bucky's review

update comment [ci skip]

test TxEventBuffer

update changelog

fix TestValidatorSetChanges (2nd attempt)

only do wg.Done when no errors

benchmark event bus

create pubsub server inside NewEventBus

only expose config params (later if needed)

set buffer capacity to 0 so we are not testing cache

new tx event format: key = "Tx" plus a tag {"tx.hash": XYZ}

This should allow to subscribe to all transactions! or a specific one
using a query: "tm.events.type = Tx and tx.hash = '013ABF99434...'"

use TimeoutCommit instead of afterPublishEventNewBlockTimeout

TimeoutCommit is the time a node waits after committing a block, before
it goes into the next height. So it will finish everything from the last
block, but then wait a bit. The idea is this gives it time to hear more
votes from other validators, to strengthen the commit it includes in the
next block. But it also gives it time to hear about new transactions.

waitForBlockWithUpdatedVals

rewrite WAL crash tests

Task:
test that we can recover from any WAL crash.

Solution:
the old tests were relying on event hub being run in the same thread (we
were injecting the private validator's last signature).

when considering a rewrite, we considered two possible solutions: write
a "fuzzy" testing system where WAL is crashing upon receiving a new
message, or inject failures and trigger them in tests using something
like https://github.com/coreos/gofail.

remove sleep

no cs.Lock around wal.Save

test different cases (empty block, non-empty block, ...)

comments

add comments

test 4 cases: empty block, non-empty block, non-empty block with smaller part size, many blocks

fixes as per Bucky's last review

reset subscriptions on UnsubscribeAll

use a simple counter to track message for which we panicked

also, set a smaller part size for all test cases

int

int

make lint happy

remove dead code

remove not needed go-common dependency

check peer.Send failures (Refs #174)