1.byfn.sh up down会清理所有容器镜像,生成的配置文件和证书,现实场景应该可以停止或恢复区块链网络,该如何处理?

byfn.sh down会调用networkdDown去销毁整个网络和已生成的配置。byfn.sh restart则不会清理。

# Tear down running network
function networkDown() {
  # stop org3 containers also in addition to org1 and org2, in case we were running sample to add org3
  docker-compose -f $COMPOSE_FILE -f $COMPOSE_FILE_COUCH -f $COMPOSE_FILE_ORG3 down --volumes --remove-orphans

  # Don't remove the generated artifacts -- note, the ledgers are always removed
  if [ "$MODE" != "restart" ]; then
    # Bring down the network, deleting the volumes
    #Delete any ledger backups
    docker run -v $PWD:/tmp/first-network --rm hyperledger/fabric-tools:$IMAGETAG rm -Rf /tmp/first-network/ledgers-backup
    #Cleanup the chaincode containers
    clearContainers
    #Cleanup images
    removeUnwantedImages
    # remove orderer block and other channel configuration transactions and certs
    rm -rf channel-artifacts/*.block channel-artifacts/*.tx crypto-config ./org3-artifacts/crypto-config/ channel-artifacts/org3.json
    # remove the docker-compose yaml file that was customized to the example
    rm -f docker-compose-e2e.yaml
  fi
}

# Generate the needed certificates, the genesis block and start the network.
function networkUp() {
  checkPrereqs
  # generate artifacts if they don't exist
  if [ ! -d "crypto-config" ]; then
    generateCerts
    replacePrivateKey
    generateChannelArtifacts
  fi
  if [ "${IF_COUCHDB}" == "couchdb" ]; then
    IMAGE_TAG=$IMAGETAG docker-compose -f $COMPOSE_FILE -f $COMPOSE_FILE_COUCH up -d 2>&1
  else
    IMAGE_TAG=$IMAGETAG docker-compose -f $COMPOSE_FILE up -d 2>&1
  fi
  if [ $? -ne 0 ]; then
    echo "ERROR !!!! Unable to start network"
    exit 1
  fi
  # now run the end to end script
  docker exec cli scripts/script.sh $CHANNEL_NAME $CLI_DELAY $LANGUAGE $CLI_TIMEOUT $VERBOSE
  if [ $? -ne 0 ]; then
    echo "ERROR !!!! Test failed"
    exit 1
  fi
}

注意 docker-compose down会停止和删除容器,网络,镜像和映射的卷。 只是停止服务的话的会最好使用docker-compose stop。 docker-compose up则是创建和启动容器服务, 这里用于启动。

我们也可以参考例子fabric-samples/fabcar, 它会重用fabric-samples/basic-network中的start.sh, stop.sh允许停止和重启。

2.byfn.sh还是fabcar两个例子即使重启区块链网络,通道需要创新创建,节点需要重新加入通道,链码也要全要重新安装,如果节点多维护起来就麻烦且费时,重启的时候能让通道,节点,链码,State DB自动恢复?

这自然是有的,但是必须开启orderer, peer等的持久化配置。

以/fabric-samples/basic-networkd的docker-compose.yaml为例, 配置services, 容器路径通常包含production的则是持久化路径的映射配置, 见蓝色部分。

  orderer.example.com:
    container_name: orderer.example.com
    image: hyperledger/fabric-orderer
    environment:
      - ORDERER_GENERAL_LOGLEVEL=info
      - ORDERER_GENERAL_LISTENADDRESS=0.0.0.0
      - ORDERER_GENERAL_GENESISMETHOD=file
      - ORDERER_GENERAL_GENESISFILE=/etc/hyperledger/configtx/genesis.block
      - ORDERER_GENERAL_LOCALMSPID=OrdererMSP
      - ORDERER_GENERAL_LOCALMSPDIR=/etc/hyperledger/msp/orderer/msp
    working_dir: /opt/gopath/src/github.com/hyperledger/fabric/orderer
    command: orderer
    ports:
      - 7050:7050
    volumes:
        - ./config/:/etc/hyperledger/configtx
        - ./crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/:/etc/hyperledger/msp/orderer
        - ./crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/:/etc/hyperledger/msp/peerOrg1
        - /mnt/hyperledger/orderer:/var/hyperledger/production/orderer
    networks


 peer0.org1.example.com:
    container_name: peer0.org1.example.com
    image: hyperledger/fabric-peer
    environment:
      - CORE_VM_ENDPOINT=unix:///host/var/run/docker.sock
      - CORE_PEER_ID=peer0.org1.example.com
      - CORE_LOGGING_PEER=info
      - CORE_CHAINCODE_LOGGING_LEVEL=info
      - CORE_PEER_LOCALMSPID=Org1MSP
      - CORE_PEER_MSPCONFIGPATH=/etc/hyperledger/msp/peer/
      - CORE_PEER_ADDRESS=peer0.org1.example.com:7051
      # # the following setting starts chaincode containers on the same
      # # bridge network as the peers
      # # https://docs.docker.com/compose/networking/
      - CORE_VM_DOCKER_HOSTCONFIG_NETWORKMODE=${COMPOSE_PROJECT_NAME}_basic
      - CORE_LEDGER_STATE_STATEDATABASE=CouchDB
      - CORE_LEDGER_STATE_COUCHDBCONFIG_COUCHDBADDRESS=couchdb:5984
      # The CORE_LEDGER_STATE_COUCHDBCONFIG_USERNAME and CORE_LEDGER_STATE_COUCHDBCONFIG_PASSWORD
      # provide the credentials for ledger to connect to CouchDB.  The username and password must
      # match the username and password set for the associated CouchDB.
      - CORE_LEDGER_STATE_COUCHDBCONFIG_USERNAME=
      - CORE_LEDGER_STATE_COUCHDBCONFIG_PASSWORD=
    working_dir: /opt/gopath/src/github.com/hyperledger/fabric
    command: peer node start
    # command: peer node start --peer-chaincodedev=true
    ports:
      - 7051:7051
      - 7053:7053
    volumes:
        - /var/run/:/host/var/run/
        - ./crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/msp:/etc/hyperledger/msp/peer
        - ./crypto-config/peerOrganizations/org1.example.com/users:/etc/hyperledger/msp/users
        - ./config:/etc/hyperledger/configtx
        - /mnt/hyperledger/org1/peer0:/var/hyperledger/production

    depends_on:
      - orderer.example.com
      - couchdb
    networks:
      - basic

  couchdb:
    container_name: couchdb
    image: hyperledger/fabric-couchdb
    # Populate the COUCHDB_USER and COUCHDB_PASSWORD to set an admin user and password
    # for CouchDB.  This will prevent CouchDB from operating in an "Admin Party" mode.
    environment:
      - COUCHDB_USER=
      - COUCHDB_PASSWORD=
    ports:
      - 5984:5984
    networks:
      - basic
    volumes:
      - /mnt/hyperledger/couchdb:/opt/couchdb/data

3.Peer节点默认使用level DB作为state DB, key-value键值对查询较弱, couch DB支付富查询,如何配置?

byfn.sh up -c mychannel -s couchdb 实际使用的配置文件是cker-compose-couch.yaml,

services:
  couchdb0:
    container_name: couchdb0
    image: hyperledger/fabric-couchdb
    # Populate the COUCHDB_USER and COUCHDB_PASSWORD to set an admin user and password
    # for CouchDB.  This will prevent CouchDB from operating in an "Admin Party" mode.
    environment:
      - COUCHDB_USER=
      - COUCHDB_PASSWORD=
    # Comment/Uncomment the port mapping if you want to hide/expose the CouchDB service,
    # for example map it to utilize Fauxton User Interface in dev environments.
    ports:
      - "5984:5984"
    networks:
      - byfn

  peer0.org1.example.com:
    environment:
      - CORE_LEDGER_STATE_STATEDATABASE=CouchDB
      - CORE_LEDGER_STATE_COUCHDBCONFIG_COUCHDBADDRESS=couchdb0:5984
      # The CORE_LEDGER_STATE_COUCHDBCONFIG_USERNAME and CORE_LEDGER_STATE_COUCHDBCONFIG_PASSWORD
      # provide the credentials for ledger to connect to CouchDB.  The username and password must
      # match the username and password set for the associated CouchDB.
      - CORE_LEDGER_STATE_COUCHDBCONFIG_USERNAME=
      - CORE_LEDGER_STATE_COUCHDBCONFIG_PASSWORD=
    depends_on:
      - couchdb0

peer主要设置连接的couchdb地址和账号, couchdb主要是配置对应端口号,couchDB还支持一些字段的索引,在学习链码的时候我们再深入。

4.Peer节点我们配置了两个端口,配置用来做什么?

参看fabric-samples/first-network/base/docker-compose-base.yaml

  peer0.org1.example.com:
    container_name: peer0.org1.example.com
    extends:
      file: peer-base.yaml
      service: peer-base
    environment:
      - CORE_PEER_ID=peer0.org1.example.com
      - CORE_PEER_ADDRESS=peer0.org1.example.com:7051
      - CORE_PEER_GOSSIP_BOOTSTRAP=peer1.org1.example.com:7051
      - CORE_PEER_GOSSIP_EXTERNALENDPOINT=peer0.org1.example.com:7051
      - CORE_PEER_LOCALMSPID=Org1MSP
    volumes:
        - /var/run/:/host/var/run/
        - ../crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/msp:/etc/hyperledger/fabric/msp
        - ../crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls:/etc/hyperledger/fabric/tls
        - peer0.org1.example.com:/var/hyperledger/production
    ports:
      - 7051:7051
      - 7053:7053

7051是Peer启动的gRPC, 一般是客户端应用接入。 7053是事件端口(Peer Event)

Fabric 1.1之前, 被定位为Event Hub(节点的消息中心), 当Peer节点记账本副本追加了新的区块的时候,都会通知订阅了这些消息的客户端应用。以fabcar的invoke.js代码为例

                console.log(util.format(
                        'Successfully sent Proposal and received ProposalResponse: Status - %s, message - "%s"',
                        proposalResponses[0].response.status, proposalResponses[0].response.message));

                // build up the request for the orderer to have the transaction committed
                var request = {
                        proposalResponses: proposalResponses,
                        proposal: proposal
                };

                // set the transaction listener and set a timeout of 30 sec
                // if the transaction did not get committed within the timeout period,
                // report a TIMEOUT status
                var transaction_id_string = tx_id.getTransactionID(); //Get the transaction ID string to be used by the event processing
                var promises = [];

                var sendPromise = channel.sendTransaction(request);
                promises.push(sendPromise); //we want the send transaction first, so that we know where to check status

                // get an eventhub once the fabric client has a user assigned. The user
                // is required bacause the event registration must be signed
                let event_hub = fabric_client.newEventHub();
                event_hub.setPeerAddr('grpc://localhost:7053');

                // using resolve the promise so that result status may be processed
                // under the then clause rather than having the catch clause process
                // the status
                let txPromise = new Promise((resolve, reject) => {
                        let handle = setTimeout(() => {
                                event_hub.disconnect();
                                resolve({event_status : 'TIMEOUT'}); //we could use reject(new Error('Trnasaction did not complete within 30 seconds'));
                        }, 3000);
                        event_hub.connect();
                        event_hub.registerTxEvent(transaction_id_string, (tx, code) => {
                                // this is the callback for transaction event status
                                // first some clean up of event listener
                                clearTimeout(handle);
                                event_hub.unregisterTxEvent(transaction_id_string);
                                event_hub.disconnect();

                                // now let the application know what happened
                                var return_status = {event_status : code, tx_id : transaction_id_string};
                                if (code !== 'VALID') {
                                        console.error('The transaction was invalid, code = ' + code);
                                        resolve(return_status); // we could use reject(new Error('Problem with the tranaction, event status ::'+code));
                                } else {
                                        console.log('The transaction has been committed on peer ' + event_hub._ep._endpoint.addr);
                                        resolve(return_status);
                                }
                        }, (err) => {
                                //this is the callback if something goes wrong with the event registration or processing
                                reject(new Error('There was a problem with the eventhub ::'+err));
                        });
                });
                promises.push(txPromise);

                return Promise.all(promises);

Fabric 1.1之后peer event做了完全不同的设计,消息的监听不在peer节点了,而是基于channel,这样设计提供了对Peer数据更细粒度的采访控制和提供了接收消息的可靠性。(官方文档是这么扯,我也有点疑惑) 主要提供两种服务,Deliver(通知提交到记账本的整个区块内容) 和DeliverFiltered(过滤一些区块减少消息通知返回的区块大小)

有点晦涩, 找了下Java SDK的代码看下。

/**
     * This code test the replay feature of the new peer event services.
     * Instead of the default of starting the eventing peer to retrieve the newest block it sets it
     * retrieve starting from the start parameter. Also checks with block and filterblock replays.
     * Depends on end2end and end2endAndBackagain of have fully run to have the blocks need to work with.
     *
     * @param client
     * @param replayTestChannel
     * @param start
     * @param stop
     * @param useFilteredBlocks
     * @throws InvalidArgumentException
     */

    private void testPeerServiceEventingReplay(HFClient client, Channel replayTestChannel, final long start, final long stop,
                                               final boolean useFilteredBlocks) throws InvalidArgumentException {

        if (testConfig.isRunningAgainstFabric10()) {
            return; // not supported for v1.0
        }

        assertFalse(replayTestChannel.isInitialized()); //not yet initialized
        assertFalse(replayTestChannel.isShutdown()); // not yet shutdown.

        //Remove all peers just have one ledger peer and one eventing peer.
        List<Peer> savedPeers = new ArrayList<>(replayTestChannel.getPeers());
        for (Peer peer : savedPeers) {
            replayTestChannel.removePeer(peer);
        }
        assertTrue(savedPeers.size() > 1); //need at least two
        Peer eventingPeer = savedPeers.remove(0);
        eventingPeer = client.newPeer(eventingPeer.getName(), eventingPeer.getUrl(), eventingPeer.getProperties());
        Peer ledgerPeer = savedPeers.remove(0);
        ledgerPeer = client.newPeer(ledgerPeer.getName(), ledgerPeer.getUrl(), ledgerPeer.getProperties());

        assertTrue(replayTestChannel.getPeers().isEmpty()); // no more peers.
        assertTrue(replayTestChannel.getPeers(EnumSet.of(PeerRole.CHAINCODE_QUERY, PeerRole.ENDORSING_PEER)).isEmpty()); // just checking :)
        assertTrue(replayTestChannel.getPeers(EnumSet.of(PeerRole.LEDGER_QUERY)).isEmpty()); // just checking

        assertNotNull(client.getChannel(replayTestChannel.getName())); // should be known by client.

        final PeerOptions eventingPeerOptions = createPeerOptions().setPeerRoles(EnumSet.of(PeerRole.EVENT_SOURCE));
        if (useFilteredBlocks) {
            eventingPeerOptions.registerEventsForFilteredBlocks();
        }

        if (-1L == stop) { //the height of the blockchain

            replayTestChannel.addPeer(eventingPeer, eventingPeerOptions.startEvents(start)); // Eventing peer start getting blocks from block 0
        } else {
            replayTestChannel.addPeer(eventingPeer, eventingPeerOptions
                    .startEvents(start).stopEvents(stop)); // Eventing peer start getting blocks from block 0
        }
        //add a ledger peer
        replayTestChannel.addPeer(ledgerPeer, createPeerOptions().setPeerRoles(EnumSet.of(PeerRole.LEDGER_QUERY)));

        CompletableFuture<Long> done = new CompletableFuture<>(); // future to set when done.
        // some variable used by the block listener being set up.
        final AtomicLong bcount = new AtomicLong(0);
        final AtomicLong stopValue = new AtomicLong(stop == -1L ? Long.MAX_VALUE : stop);
        final Channel finalChannel = replayTestChannel;

        final Map<Long, BlockEvent> blockEvents = Collections.synchronizedMap(new HashMap<>(100));

        final String blockListenerHandle = replayTestChannel.registerBlockListener(blockEvent -> { // register a block listener

            try {
                final long blockNumber = blockEvent.getBlockNumber();
                BlockEvent seen = blockEvents.put(blockNumber, blockEvent);
                assertNull(format("Block number %d seen twice", blockNumber), seen);

                assertTrue(format("Wrong type of block seen block number %d. expected filtered block %b but got %b",
                        blockNumber, useFilteredBlocks, blockEvent.isFiltered()),
                        useFilteredBlocks ? blockEvent.isFiltered() : !blockEvent.isFiltered());
                final long count = bcount.getAndIncrement(); //count starts with 0 not 1 !

                //out("Block count: %d, block number: %d  received from peer: %s", count, blockNumber, blockEvent.getPeer().getName());

                if (count == 0 && stop == -1L) {
                    final BlockchainInfo blockchainInfo = finalChannel.queryBlockchainInfo();

                    long lh = blockchainInfo.getHeight();
                    stopValue.set(lh - 1L);  // blocks 0L 9L are on chain height 10 .. stop on 9
                    //  out("height: %d", lh);
                    if (bcount.get() + start > stopValue.longValue()) { // test with latest count.
                        done.complete(bcount.get()); // report back latest count.
                    }

                } else {
                    if (bcount.longValue() + start > stopValue.longValue()) {
                        done.complete(count);
                    }
                }
            } catch (AssertionError | Exception e) {
                e.printStackTrace();
                done.completeExceptionally(e);
            }

        });

        try {
            replayTestChannel.initialize(); // start it all up.
            done.get(30, TimeUnit.SECONDS); // give a timeout here.
            Thread.sleep(1000); // sleep a little to see if more blocks trickle in .. they should not
            replayTestChannel.unregisterBlockListener(blockListenerHandle);

            final long expectNumber = stopValue.longValue() - start + 1L; // Start 2 and stop is 3  expect 2

            assertEquals(format("Didn't get number we expected %d but got %d block events. Start: %d, end: %d, height: %d",
                    expectNumber, blockEvents.size(), start, stop, stopValue.longValue()), expectNumber, blockEvents.size());

            for (long i = stopValue.longValue(); i >= start; i--) { //make sure all are there.
                final BlockEvent blockEvent = blockEvents.get(i);
                assertNotNull(format("Missing block event for block number %d. Start= %d", i, start), blockEvent);
            }

            //light weight test just see if we get reasonable values for traversing the block. Test just whats common between
            // Block and FilteredBlock.

            int transactionEventCounts = 0;
            int chaincodeEventsCounts = 0;

            for (long i = stopValue.longValue(); i >= start; i--) {

                final BlockEvent blockEvent = blockEvents.get(i);
//                out("blockwalker %b, start: %d, stop: %d, i: %d, block %d", useFilteredBlocks, start, stopValue.longValue(), i, blockEvent.getBlockNumber());
                assertEquals(useFilteredBlocks, blockEvent.isFiltered()); // check again

                if (useFilteredBlocks) {
                    assertNull(blockEvent.getBlock()); // should not have raw block event.
                    assertNotNull(blockEvent.getFilteredBlock()); // should have raw filtered block.
                } else {
                    assertNotNull(blockEvent.getBlock()); // should not have raw block event.
                    assertNull(blockEvent.getFilteredBlock()); // should have raw filtered block.
                }

                assertEquals(replayTestChannel.getName(), blockEvent.getChannelId());

                for (BlockInfo.EnvelopeInfo envelopeInfo : blockEvent.getEnvelopeInfos()) {
                    if (envelopeInfo.getType() == TRANSACTION_ENVELOPE) {

                        BlockInfo.TransactionEnvelopeInfo transactionEnvelopeInfo = (BlockInfo.TransactionEnvelopeInfo) envelopeInfo;
                        assertTrue(envelopeInfo.isValid()); // only have valid blocks.
                        assertEquals(envelopeInfo.getValidationCode(), 0);

                        ++transactionEventCounts;
                        for (BlockInfo.TransactionEnvelopeInfo.TransactionActionInfo ta : transactionEnvelopeInfo.getTransactionActionInfos()) {
                            //    out("\nTA:", ta + "\n\n");
                            ChaincodeEvent event = ta.getEvent();
                            if (event != null) {
                                assertNotNull(event.getChaincodeId());
                                assertNotNull(event.getEventName());
                                chaincodeEventsCounts++;
                            }

                        }

                    } else {
                        assertEquals("Only non transaction block should be block 0.", blockEvent.getBlockNumber(), 0);

                    }

                }

            }

            assertTrue(transactionEventCounts > 0);

            if (expectNumber > 4) { // this should be enough blocks with CC events.

                assertTrue(chaincodeEventsCounts > 0);
            }

            replayTestChannel.shutdown(true); //all done.
        } catch (Exception e) {
            e.printStackTrace();
            fail(e.getMessage());
        }
    }

再结合初始化通道的代码

            boolean everyOther = false;

            for (String peerName : sampleOrg.getPeerNames()) {
                String peerLocation = sampleOrg.getPeerLocation(peerName);
                Properties peerProperties = testConfig.getPeerProperties(peerName);
                Peer peer = client.newPeer(peerName, peerLocation, peerProperties);
                final PeerOptions peerEventingOptions = // we have two peers on one use block on other use filtered
                        everyOther ?
                                createPeerOptions().registerEventsForBlocks().setPeerRoles(EnumSet.of(PeerRole.ENDORSING_PEER, PeerRole.LEDGER_QUERY, PeerRole.CHAINCODE_QUERY, PeerRole.EVENT_SOURCE)) :
                                createPeerOptions().registerEventsForFilteredBlocks().setPeerRoles(EnumSet.of(PeerRole.ENDORSING_PEER, PeerRole.LEDGER_QUERY, PeerRole.CHAINCODE_QUERY, PeerRole.EVENT_SOURCE));

                newChannel.addPeer(peer, IS_FABRIC_V10 ?
                        createPeerOptions().setPeerRoles(EnumSet.of(PeerRole.ENDORSING_PEER, PeerRole.LEDGER_QUERY, PeerRole.CHAINCODE_QUERY)) : peerEventingOptions);

                everyOther = !everyOther;
            }

Fabric-SDK在设计的时候,无论是查询,更新,大多操作都是基于org.hyperledger.fabric.sdk.Channel作为入口, 例如:

Collection<ProposalResponse> queryProposals = channel.queryByChaincode(queryByChaincodeRequest, channel.getPeers());

Collection<ProposalResponse> transactionPropResp = channel.sendTransactionProposal(transactionProposalRequest, channel.getPeers());

Event Hub基于单个Peer去监听它的消息,可能单节点会不稳定等,而通道包含多节点,消息通知可能会更稳定一些,这个7053端口应该是专门给1.1前的Event Hub版本用的,1.1之后的具体怎么回调通知, 具体实现还有待查阅源码。

5.Orderer大多例子都是SOLO配置的,Kafka如何配置?

用好Kafka里面蛮多参数需要考量,毕竟Orderer集群是共识实现的重点,后面我们专门探讨下kafka实现的共识和配置。

暂时先参考官方文档 https://hyperledger-fabric.readthedocs.io/en/release-1.2/kafka.html?highlight=kafka