./bin/cryptogen generate --config=./crypto-config.yaml

 ################################################################################

 #

 #   SECTION: Orderer

 #

 #   - This section defines the values to encode into a config transaction or

 #   genesis block for orderer related parameters

 #

 ################################################################################

 Orderer: &OrdererExample

     # Orderer Type: The orderer implementation to start

     # Available types are "solo" and "kafka"

     OrdererType: kafka

     Addresses:

         - orderer0.example.com:

         - orderer1.example.com:

         - orderer2.example.com:

     # Batch Timeout: The amount of time to wait before creating a batch

     BatchTimeout: 2s

     # Batch Size: Controls the number of messages batched into a block

     BatchSize:

         # Max Message Count: The maximum number of messages to permit in a batch

         MaxMessageCount: 

         # Absolute Max Bytes: The absolute maximum number of bytes allowed for

         # the serialized messages in a batch.

         # 设置最大的区块大小。每个区块最大有Orderer.AbsoluteMaxBytes个字节（不包括头部）。

         # 假定这里设置的值为A，记住这个值，这会影响怎样配置Kafka代理。

         AbsoluteMaxBytes:  MB

         # Preferred Max Bytes: The preferred maximum number of bytes allowed for

         # the serialized messages in a batch. A message larger than the preferred

         # max bytes will result in a batch larger than preferred max bytes.

         # 设置每个区块建议的大小。Kafka对于相对小的消息提供更高的吞吐量；区块大小最好不要超过1MB。

         PreferredMaxBytes:  KB

     Kafka:

         # Brokers: A list of Kafka brokers to which the orderer connects

         # NOTE: Use IP:port notation

         # 包含Kafka集群中至少两个代理的地址信息（IP：port），

         # 这个list不需要是完全的（这些是你的种子代理），

         # 这个代理表示当前Order所要连接的Kafka代理。

         Brokers:

             - x.x.x.x:

             - x.x.x.xx:

     # Organizations is the list of orgs which are defined as participants on

     # the orderer side of the network

     Organizations:

 # Copyright IBM Corp. All Rights Reserved.

 #

 # SPDX-License-Identifier: Apache-2.0

 #

 # ZooKeeper的基本运转流程：

 # 、选举Leader。

 # 、同步数据。

 # 、选举Leader过程中算法有很多，但要达到的选举标准是一致的。

 # 、Leader要具有最高的执行ID，类似root权限。

 # 、集群中大多数的机器得到响应并follow选出的Leader。

 #

 version: ''

 services:

   zookeeper1:

     container_name: zookeeper1

     hostname: zookeeper1

     image: hyperledger/fabric-zookeeper

     restart: always

     environment:

       # ========================================================================

       #     Reference: https://zookeeper.apache.org/doc/r3.4.9/zookeeperAdmin.html#sc_configuration

       # ========================================================================

       #

       # myid

       # The ID must be unique within the ensemble and should have a value

       # ID在集合中必须是唯一的并且应该有一个值

       # between  and .

       # 在1和255之间。

       - ZOO_MY_ID=

       #

       # server.x=[hostname]:nnnnn[:nnnnn]

       # The list of servers that make up the ZK ensemble. The list that is used

       # by the clients must match the list of ZooKeeper servers that each ZK

       # server has. There are two port numbers `nnnnn`. The first is what

       # followers use to connect to the leader, while the second is for leader

       # election.

       # 组成ZK集合的服务器列表。客户端使用的列表必须与ZooKeeper服务器列表所拥有的每一个ZK服务器相匹配。

       # 有两个端口号 `nnnnn`。第一个是追随者用来连接领导者的东西，第二个是领导人选举。

       - ZOO_SERVERS=server.=zookeeper1:: server.=zookeeper2:: server.=zookeeper3::

     ports:

       - "2181:2181"

       - "2888:2888"

       - "3888:3888"

     extra_hosts:

      - "zookeeper1:x.x.x.x"

      - "zookeeper2:x.x.x.xx"

      - "zookeeper3:x.x.x.xxx"

      - "kafka1:xx.x.x.x"

      - "kafka2:xx.x.x.xx"

      - "kafka3:xx.x.x.xxx"

      - "kafka3:xx.x.x.xxxx"

 # Copyright IBM Corp. All Rights Reserved.

 #

 # SPDX-License-Identifier: Apache-2.0

 #

 version: ''

 services:

   kafka1:

     container_name: kafka1

     hostname: kafka1

     image: hyperledger/fabric-kafka

     restart: always

     environment:

       # ========================================================================

       #     Reference: https://kafka.apache.org/documentation/#configuration

       # ========================================================================

       #

       # broker.id

       - KAFKA_BROKER_ID=

       #

       # min.insync.replicas

       # Let the value of this setting be M. Data is considered committed when

       # it is written to at least M replicas (which are then considered in-sync

       # and belong to the in-sync replica set, or ISR). In any other case, the

       # write operation returns an error. Then:

       # . If up to M-N replicas -- out of the N (see default.replication.factor

       # below) that the channel data is written to -- become unavailable,

       # operations proceed normally.

       # . If more replicas become unavailable, Kafka cannot maintain an ISR set

       # of M, so it stops accepting writes. Reads work without issues. The

       # channel becomes writeable again when M replicas get in-sync.

       #

       # min.insync.replicas = M---设置一个M值（例如1<M<N，查看下面的default.replication.factor）

       # 数据提交时会写入至少M个副本（这些数据然后会被同步并且归属到in-sync 副本集合或ISR）。

       # 其它情况，写入操作会返回一个错误。接下来：

       # ）如果channel写入的数据多达N-M个副本变的不可用，操作可以正常执行。

       # ）如果有更多的副本不可用，Kafka不可以维护一个有M数量的ISR集合，因此Kafka停止接收写操作。Channel只有当同步M个副本后才可以重新可以写。

       - KAFKA_MIN_INSYNC_REPLICAS=

       #

       # default.replication.factor

       # Let the value of this setting be N. A replication factor of N means that

       # each channel will have its data replicated to N brokers. These are the

       # candidates for the ISR set of a channel. As we noted in the

       # min.insync.replicas section above, not all of these brokers have to be

       # available all the time. In this sample configuration we choose a

       # default.replication.factor of K- (where K is the total number of brokers in

       # our Kafka cluster) so as to have the largest possible candidate set for

       # a channel's ISR. We explicitly avoid setting N equal to K because

       # channel creations cannot go forward if less than N brokers are up. If N

       # were set equal to K, a single broker going down would mean that we would

       # not be able to create new channels, i.e. the crash fault tolerance of

       # the ordering service would be non-existent.

       #

       # 设置一个值N，N<K。

       # 设置replication factor参数为N代表着每个channel都保存N个副本的数据到Kafka的代理上。

       # 这些都是一个channel的ISR集合的候选。

       # 如同在上边min.insync.replicas section设置部分所描述的，不是所有的代理（orderer）在任何时候都是可用的。

       # N的值必须小于K，如果少于N个代理的话，channel的创建是不能成功的。

       # 因此，如果设置N的值为K，一个代理失效后，那么区块链网络将不能再创建新的channel---orderering service的crash容错也就不存在了。

       - KAFKA_DEFAULT_REPLICATION_FACTOR=

       #

       # zookeper.connect

       # Point to the set of Zookeeper nodes comprising a ZK ensemble.

       # 指向Zookeeper节点的集合，其中包含ZK的集合。

       - KAFKA_ZOOKEEPER_CONNECT=zookeeper1:,zookeeper2:,zookeeper3:

       #

       # zookeeper.connection.timeout.ms

       # The max time that the client waits to establish a connection to

       # Zookeeper. If not set, the value in zookeeper.session.timeout.ms (below)

       # is used.

       #- KAFKA_ZOOKEEPER_CONNECTION_TIMEOUT_MS =

       #

       # zookeeper.session.timeout.ms

       #- KAFKA_ZOOKEEPER_SESSION_TIMEOUT_MS =

       #

       # socket.request.max.bytes

       # The maximum number of bytes in a socket request. ATTN: If you set this

       # env var, make sure to update `brokerConfig.Producer.MaxMessageBytes` in

       # `newBrokerConfig()` in `fabric/orderer/kafka/config.go` accordingly.

       #- KAFKA_SOCKET_REQUEST_MAX_BYTES= #  *  *  B

       #

       # message.max.bytes

       # The maximum size of envelope that the broker can receive.

       #

       # 在configtx.yaml中会设置最大的区块大小（参考configtx.yaml中AbsoluteMaxBytes参数）。

       # 每个区块最大有Orderer.AbsoluteMaxBytes个字节（不包括头部），假定这里设置的值为A（目前99）。

       # message.max.bytes和replica.fetch.max.bytes应该设置一个大于A。

       # 为header增加一些缓冲区空间---1MB已经足够大。上述不同设置值之间满足如下关系：

       # Orderer.AbsoluteMaxBytes < replica.fetch.max.bytes <= message.max.bytes

       # （更完整的是，message.max.bytes应该严格小于socket.request.max.bytes的值，socket.request.max.bytes的值默认被设置为100MB。

       # 如果想要区块的大小大于100MB，需要编辑fabric/orderer/kafka/config.go文件里硬编码的值brokerConfig.Producer.MaxMessageBytes，

       # 修改后重新编译源码得到二进制文件，这种设置是不建议的。）

       - KAFKA_MESSAGE_MAX_BYTES= #  *  *  B

       #

       # replica.fetch.max.bytes

       # The number of bytes of messages to attempt to fetch for each channel.

       # This is not an absolute maximum, if the fetched envelope is larger than

       # this value, the envelope will still be returned to ensure that progress

       # can be made. The maximum message size accepted by the broker is defined

       # via message.max.bytes above.

       #

       # 试图为每个通道获取的消息的字节数。

       # 这不是绝对最大值，如果获取的信息大于这个值，则仍然会返回信息，以确保可以取得进展。

       # 代理所接受的最大消息大小是通过上一条message.max.bytes定义的。

       - KAFKA_REPLICA_FETCH_MAX_BYTES= #  *  *  B

       #

       # unclean.leader.election.enable

       # Data consistency is key in a blockchain environment. We cannot have a

       # leader chosen outside of the in-sync replica set, or we run the risk of

       # overwriting the offsets that the previous leader produced, and --as a

       # result-- rewriting the blockchain that the orderers produce.

       # 数据一致性在区块链环境中是至关重要的。

       # 我们不能从in-sync 副本（ISR）集合之外选取channel leader，

       # 否则我们将会面临对于之前的leader产生的offsets覆盖的风险，

       # 这样的结果是，orderers产生的区块可能会重新写入区块链。

       - KAFKA_UNCLEAN_LEADER_ELECTION_ENABLE=false

       #

       # log.retention.ms

       # Until the ordering service in Fabric adds support for pruning of the

       # Kafka logs, time-based retention should be disabled so as to prevent

       # segments from expiring. (Size-based retention -- see

       # log.retention.bytes -- is disabled by default so there is no need to set

       # it explicitly.)

       #

       # 除非orderering service对Kafka日志的修剪增加支持，

       # 否则需要关闭基于时间的日志保留方式并且避免分段到期

       # （基于大小的日志保留方式log.retention.bytes在写本文章时在Kafka中已经默认关闭，因此不需要再次明确设置这个配置）。

       - KAFKA_LOG_RETENTION_MS=-

     ports:

       - "9092:9092"

     extra_hosts:

      - "zookeeper1:x.x.x.x"

      - "zookeeper2:x.x.x.xx"

      - "zookeeper3:x.x.x.xxx"

      - "kafka1:xx.x.x.x"

      - "kafka2:xx.x.x.xx"

      - "kafka3:xx.x.x.xxx"

      - "kafka4:xx.x.x.xxxx"

 # Copyright IBM Corp. All Rights Reserved.

 #

 # SPDX-License-Identifier: Apache-2.0

 #

 version: ''

 services:

   orderer0.example.com:

     container_name: orderer0.example.com

     image: hyperledger/fabric-orderer

     environment:

       - CORE_VM_DOCKER_HOSTCONFIG_NETWORKMODE=example_default

       - ORDERER_GENERAL_LOGLEVEL=error

       # - ORDERER_GENERAL_LOGLEVEL=debug

       - ORDERER_GENERAL_LISTENADDRESS=0.0.0.0

       - ORDERER_GENERAL_LISTENPORT=

       #- ORDERER_GENERAL_GENESISPROFILE=ExampleOrdererGenesis

       - ORDERER_GENERAL_GENESISMETHOD=file

       - ORDERER_GENERAL_GENESISFILE=/var/hyperledger/orderer/orderer.genesis.block

       - ORDERER_GENERAL_LOCALMSPID=ExampleMSP

       - ORDERER_GENERAL_LOCALMSPDIR=/var/hyperledger/orderer/msp

       #- ORDERER_GENERAL_LEDGERTYPE=ram

       #- ORDERER_GENERAL_LEDGERTYPE=file

       # enabled TLS

       - ORDERER_GENERAL_TLS_ENABLED=false

       - ORDERER_GENERAL_TLS_PRIVATEKEY=/var/hyperledger/orderer/tls/server.key

       - ORDERER_GENERAL_TLS_CERTIFICATE=/var/hyperledger/orderer/tls/server.crt

       - ORDERER_GENERAL_TLS_ROOTCAS=[/var/hyperledger/orderer/tls/ca.crt]

       - ORDERER_KAFKA_RETRY_LONGINTERVAL=10s

       - ORDERER_KAFKA_RETRY_LONGTOTAL=100s

       - ORDERER_KAFKA_RETRY_SHORTINTERVAL=1s

       - ORDERER_KAFKA_RETRY_SHORTTOTAL=30s

       - ORDERER_KAFKA_VERBOSE=true

       - ORDERER_KAFKA_BROKERS=[xx.x.x.x:,xx.x.x.xx:,xx.x.x.xxx:,xx.x.x.xxxx:]

     working_dir: /opt/gopath/src/github.com/hyperledger/fabric

     command: orderer

     volumes:

     - ../config/channel-artifacts/genesis.block:/var/hyperledger/orderer/orderer.genesis.block

     - ../config/crypto-config/ordererOrganizations/example.com/orderers/orderer0.example.com/msp:/var/hyperledger/orderer/msp

     - ../config/crypto-config/ordererOrganizations/example.com/orderers/orderer0.example.com/tls/:/var/hyperledger/orderer/tls

     networks:

       default:

         aliases:

           - example

     ports:

       - :

     extra_hosts:

      - "kafka1:xx.x.x.x"

      - "kafka2:xx.x.x.xx"

      - "kafka3:xx.x.x.xxx"

      - "kafka4:xx.x.x.xxxx"