如何阅读Tendermint的日志

如何阅读Tendermint的日志

TM的完整日志可以在这里获取。本文用的日志文件来自TM v0.16。

案例走起（walk through example）

I[03-25|04:40:48.219] Starting multiAppConn                        module=proxy impl=multiAppConn
I[03-25|04:40:48.219] Starting localClient                         module=abci-client connection=query impl=localClient
I[03-25|04:40:48.219] Starting localClient                         module=abci-client connection=mempool impl=localClient
I[03-25|04:40:48.219] Starting localClient                         module=abci-client connection=consensus impl=localClient

首先，创建了多个应用连接（multiAppConn），具体是三个连接（query，mempool和consensu）。注意：这里的应用是指在本地以dummy运行。
接着Tendermint Core和应用完成了一次握手。

I[03-25|04:40:48.219] ABCI Handshake                               module=consensus appHeight=0 appHash=
I[03-25|04:40:48.219] ABCI Replay Blocks                           module=consensus appHeight=0 storeHeight=0 stateHeight=0
I[03-25|04:40:48.219] Completed ABCI Handshake - Tendermint and App are synced module=consensus appHeight=0 appHash=

之后，开启了一系列的服务（为正式启动node做准备），例如事件开关（event switch），reactor以及为了检测IP地址，完成了UPNP发现。

I[03-25|04:40:48.219] This node is a validator                     module=consensus addr=BD8F0160796AEC1E6454C55CCA6AF15EACF94A2D pubKey={PubKeyInner:PubKeyEd25519{7A4BCE42785BF1B008E2B2B9117FB617153597E9E3BBE00BB93889DFA7885461}}
I[03-25|04:40:48.243] Starting Node                                module=main impl=Node
I[03-25|04:40:48.243] Starting EventBus                            module=events impl=EventBus
I[03-25|04:40:48.243] Starting RPC HTTP server on tcp socket 0.0.0.0:46657 module=rpc-server
I[03-25|04:40:48.244] Local listener                               module=p2p ip=:: port=46656
I[03-25|04:40:48.244] Getting UPNP external address                module=p2p
I[03-25|04:40:51.244] Could not perform UPNP discover              module=p2p err="read udp4 0.0.0.0:50863: i/o timeout"
I[03-25|04:40:51.244] Starting DefaultListener                     module=p2p impl=Listener(@172.31.22.212:46656)
I[03-25|04:40:51.244] P2P Node ID                                  module=main ID=6082741e5b3494908078fe5f473563f1c483d79e file=/opt/datadir/tendermint/config/node_key.json
I[03-25|04:40:51.244] Starting P2P Switch                          module=p2p impl="P2P Switch"
I[03-25|04:40:51.244] Starting EvidenceReactor                     module=evidence impl=EvidenceReactor
I[03-25|04:40:51.245] Starting PEXReactor                          module=p2p impl=PEXReactor
I[03-25|04:40:51.245] Starting AddrBook                            module=p2p book=/opt/datadir/tendermint/config/addrbook.json impl=AddrBook
I[03-25|04:40:51.245] Starting MempoolReactor                      module=mempool impl=MempoolReactor
I[03-25|04:40:51.245] Starting BlockchainReactor                   module=blockchain impl=BlockchainReactor
I[03-25|04:40:51.245] Starting ConsensusReactor                    module=consensus impl=ConsensusReactor
I[03-25|04:40:51.245] ConsensusReactor                             module=consensus fastSync=false
I[03-25|04:40:51.245] Starting ConsensusState                      module=consensus impl=ConsensusState
I[03-25|04:40:51.245] Starting baseWAL                             module=consensus wal=/opt/datadir/tendermint/data/cs.wal/wal impl=baseWAL
I[03-25|04:40:51.247] Starting TimeoutTicker                       module=consensus impl=TimeoutTicker

注意第一行，Tendermint Core报告，“此节点是验证人”。这里也可以只是观察人（正规节点）。第二行报告，Starting Node，这预示系统正式进入启动node的处理逻辑中。
接着，我们中继了来自WAL的所有消息。

I[03-25|04:40:51.248] Catchup by replaying consensus messages      module=consensus height=1
I[03-25|04:40:51.248] Replay: Done                                 module=consensus

“Started node”消息预示着node启动完毕，随时准备区块创建。

I[03-25|04:40:51.248] Started node                                module=main nodeInfo="NodeInfo{pk: {PubKeyEd25519{54E665EFA8EF7AD5763C421129F66FBD367B253788543C0E1B9CF047C45771D3}}, moniker: bootnode-hongkong, network: test-chain-MErM3n [listen 172.31.22.212:46656], version: 0.16.0 ([wire_version=0.7.2 p2p_version=0.5.0 consensus_version=v1/0.2.2 rpc_version=0.7.0/3 tx_index=on rpc_addr=tcp://0.0.0.0:46657])}"

接着是一个标准的区块创建过程，即进入到新的一轮中，提案一个区块，接收超过2/3的预投票（prevote），接着预提交（precommit）并且最终提交一个区块(finalise)。其中的细节，可以参阅介绍Tendermint共识的其他文章。

I[03-25|04:40:51.250] enterNewRound(1/0). Current: 1/0/RoundStepNewHeight module=consensus
I[03-25|04:40:51.250] enterPropose(1/0). Current: 1/0/RoundStepNewRound module=consensus
I[03-25|04:40:51.250] enterPropose: Our turn to propose            module=consensus proposer=BD8F0160796AEC1E6454C55CCA6AF15EACF94A2D privValidator="PrivValidator{BD8F0160796AEC1E6454C55CCA6AF15EACF94A2D LH:0, LR:0, LS:0}"
I[03-25|04:40:51.253] Signed proposal                              module=consensus height=1 round=0 proposal="Proposal{1/0 1:57D9BC19067F (-1,:0:000000000000) {/3FB2AD239E88.../} @ 2018-03-25T04:40:51.250Z}"
I[03-25|04:40:51.259] Received complete proposal block             module=consensus height=1 hash=2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49
I[03-25|04:40:51.259] enterPrevote(1/0). Current: 1/0/RoundStepPropose module=consensus
I[03-25|04:40:51.259] enterPrevote: ProposalBlock is valid         module=consensus height=1 round=0
I[03-25|04:40:51.261] Signed and pushed vote                       module=consensus height=1 round=0 vote="Vote{0:BD8F0160796A 1/00/1(Prevote) 2CFA5BC56A2E {/347B4DC16274.../} @ 2018-03-25T04:40:51.259Z}" err=null
I[03-25|04:40:51.265] Added to prevote                             module=consensus vote="Vote{0:BD8F0160796A 1/00/1(Prevote) 2CFA5BC56A2E {/347B4DC16274.../} @ 2018-03-25T04:40:51.259Z}" prevotes="VoteSet{H:1 R:0 T:1 +2/3:2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49:1:57D9BC19067F BA{1:X} map[]}"
I[03-25|04:40:51.265] enterPrecommit(1/0). Current: 1/0/RoundStepPrevote module=consensus
I[03-25|04:40:51.265] enterPrecommit: +2/3 prevoted proposal block. Locking module=consensus hash=2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49
I[03-25|04:40:51.267] Signed and pushed vote                       module=consensus height=1 round=0 vote="Vote{0:BD8F0160796A 1/00/2(Precommit) 2CFA5BC56A2E {/1AB356C41018.../} @ 2018-03-25T04:40:51.265Z}" err=null
I[03-25|04:40:51.271] Added to precommit                           module=consensus vote="Vote{0:BD8F0160796A 1/00/2(Precommit) 2CFA5BC56A2E {/1AB356C41018.../} @ 2018-03-25T04:40:51.265Z}" precommits="VoteSet{H:1 R:0 T:2 +2/3:2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49:1:57D9BC19067F BA{1:X} map[]}"
I[03-25|04:40:51.271] enterCommit(1/0). Current: 1/0/RoundStepPrecommit module=consensus
I[03-25|04:40:51.274] Finalizing commit of block with 0 txs        module=consensus height=1 hash=2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49 root=
I[03-25|04:40:51.274] Block{
  Header{
    ChainID:        test-chain-MErM3n
    Height:         1
    Time:           2018-03-25 12:40:51.25 +0800 CST
    NumTxs:         0
    TotalTxs:       0
    LastBlockID:    :0:000000000000
    LastCommit:
    Data:
    Validators:     7DBC0AC152D72CA2DA37CAB8D6D5A73B8DA9DC43
    App:
    Conensus:       0B8CEF95EC57AC2D96038FD0AE3901C14FAE8E73
    Results:
    Evidence:
  }#2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49
  Data{
  }#
  Data{
  }#
  Commit{
    BlockID:    :0:000000000000
    Precommits:
  }#
}#2CFA5BC56A2E5D0BB94B84EB35AD05CC8F47CC49 module=consensus
I[03-25|04:40:51.279] Executed block                               module=state height=1 validTxs=0 invalidTxs=0
I[03-25|04:40:51.281] Committed state                              module=state height=1 txs=0 appHash=0000000000000000
I[03-25|04:40:51.281] Recheck txs                                  module=mempool numtxs=0 height=1

模块列表

你可能在Tendermint的日志中看到下面这些模块。这里简单综述一下它们是做什么的。

abci-client:Tendermint充当有关一个应用的ABCI客户端，并且维护3个连接：mempool，consensu和query。
blockchain：提供存储，pool（一组peers）以及在peers之间存储以及交换区块的reactor。
consensus：Tendermint core的核心，实现了共识算法。包括两个“子模块”：wal（write-ahead logging,预写式日志）用于保证数据完整性和replay：宕机恢复后replay区块和消息。
events:简单的事件通知系统。你可以用过调用subscribe RPC方法来订阅。
mempool:内存池模块会处理所有流入系统的交易，不论它们是来自peers（即peers也可以产生交易）还是应用（应用也可以产生交易，当然主要是应用产生）。
p2p：围绕点对点通信提供了抽象。
rpc：Tendermint的RPC服务。
rpc-server:RPC服务器。
state：表示最近的状态和执行子模块（根据应用执行区块）。
types：一组公开暴露的类型和方法。

总结

区块链的日志体系很强大，通过日志我们可以知道很多技术细节。我想日志体系可能是构建基础服务类软件的重器之一吧。本文翻译了官方文档之“如何阅读日志”，在尊重原文的基础上，略做了少许注释。有关TM的更多细节可以参考我们的文章。它们是：

1、安装Tendermint
2、Windows下编译Tendermint源码遇到的坑
3、TM白皮书
4、Tendermint源码分析—协议参数部分
5、Tendermint的初始化流程分析
6、Tendermint源码分析之peer建立连接