diff --git a/doc/.project b/doc/.project new file mode 100644 index 0000000..f7597a8 --- /dev/null +++ b/doc/.project @@ -0,0 +1,11 @@ + + + doc + + + + + + + + diff --git "a/doc/articles/mycat2.0-\345\220\257\345\212\250\346\265\201\347\250\213.md" "b/doc/articles/mycat2.0-\345\220\257\345\212\250\346\265\201\347\250\213.md" new file mode 100644 index 0000000..641f961 --- /dev/null +++ "b/doc/articles/mycat2.0-\345\220\257\345\212\250\346\265\201\347\250\213.md" @@ -0,0 +1,351 @@ +1. 程序的入口是io.mycat.mycat2.MycatCore. +在main 方法中 首选取得ProxyRuntime的实例,该类是一个单例模式. +2. + +``` +runtime.setConfig(new MycatConfig()); +``` +该方法为runtime设置了一个MycatConfig ,MycatConfig 是负责读取配置文件的. + +3. +``` +ConfigLoader.INSTANCE.loadCore(); +``` + +调用ConfigLoader 进行配置文件的加载. + + 3.1. 加载mycat.yml,heartbeat.yml,cluster.yml,balancer.yml,user.yml 的配置文件.代码如下: + +``` +public void loadCore() throws IOException { + loadConfig(ConfigEnum.PROXY, GlobalBean.INIT_VERSION); + loadConfig(ConfigEnum.HEARTBEAT, GlobalBean.INIT_VERSION); + loadConfig(ConfigEnum.CLUSTER, GlobalBean.INIT_VERSION); + loadConfig(ConfigEnum.BALANCER, GlobalBean.INIT_VERSION); + loadConfig(ConfigEnum.USER, GlobalBean.INIT_VERSION); +} +``` + 3.2 进行配置文件的加载,调用了YamlUtil进行加载,并将配置信息赋值给MycatConfig,关键代码如下 : + +``` + conf.putConfig(configEnum, (Configurable) YamlUtil.load(fileName, configEnum.getClazz()), version); +``` + 3.3 在io.mycat.util.YamlUtil.load(String, Class) 中,处理也很简单,通过Yaml进行文件的加载,然后通过反射机制将属性进行赋值.代码如下: + +``` +/** + * 从指定的文件中加载配置 + * @param fileName 需要加载的文件名 + * @param clazz 加载后需要转换成的类对象 + * @return + * @throws FileNotFoundException + */ +public static T load(String fileName, Class clazz) throws FileNotFoundException { + InputStreamReader fis = null; + try { + URL url = YamlUtil.class.getClassLoader().getResource(fileName); + if (url != null) { + Yaml yaml = new Yaml(); + fis = new InputStreamReader(new FileInputStream(url.getFile()), StandardCharsets.UTF_8); + T obj = yaml.loadAs(fis, clazz); + return obj; + } + return null; + } finally { + if (fis != null) { + try { + fis.close(); + } catch (IOException ignored) { + } + } + } +} +``` +4. 进行通过命令行传入参数的解析.如:可以传入 + - -mycat.proxy.port 8067 + - -mycat.cluster.enable true + - -mycat.cluster.port 9067 + - -mycat.cluster.myNodeId leader-2 + +参数等 +支持的参数可在 io.mycat.mycat2.beans.ArgsBean 中进行查看. + + 获得参数后通过遍历进行赋值操作即可,代码如下: + +``` +private static void solveArgs(String[] args) { +int lenght = args.length; + +MycatConfig conf = ProxyRuntime.INSTANCE.getConfig(); +ProxyConfig proxyConfig = conf.getConfig(ConfigEnum.PROXY); +ClusterConfig clusterConfig = conf.getConfig(ConfigEnum.CLUSTER); +BalancerConfig balancerConfig= conf.getConfig(ConfigEnum.BALANCER); + +for (int i = 0; i < lenght; i++) { + switch(args[i]) { + case ArgsBean.PROXY_PORT: + proxyConfig.getProxy().setPort(Integer.parseInt(args[++i])); + break; + case ArgsBean.CLUSTER_ENABLE: + clusterConfig.getCluster().setEnable(Boolean.parseBoolean(args[++i])); + break; + case ArgsBean.CLUSTER_PORT: + clusterConfig.getCluster().setPort(Integer.parseInt(args[++i])); + break; + case ArgsBean.CLUSTER_MY_NODE_ID: + clusterConfig.getCluster().setMyNodeId(args[++i]); + break; + case ArgsBean.BALANCER_ENABLE: + balancerConfig.getBalancer().setEnable(Boolean.parseBoolean(args[++i])); + break; + case ArgsBean.BALANCER_PORT: + balancerConfig.getBalancer().setPort(Integer.parseInt(args[++i])); + break; + case ArgsBean.BALANCER_STRATEGY: + BalancerBean.BalancerStrategyEnum strategy = BalancerBean.BalancerStrategyEnum.getEnum(args[++i]); + if (strategy == null) { + throw new IllegalArgumentException("no such balancer strategy"); + } + balancerConfig.getBalancer().setStrategy(strategy); + break; + default: + break; + } +} +} +``` + + + +5. 设置NioReactorThreads,线程数目按照cpu的数目而定. + +``` +int cpus = Runtime.getRuntime().availableProcessors(); +runtime.setNioReactorThreads(cpus); +runtime.setReactorThreads(new MycatReactorThread[cpus]); +``` +6.设置MycatSessionManager + +7. 然后调用io.mycat.proxy.ProxyRuntime 的init方法,进行资源的初始化.代码如下: + +``` +public void init() { +//心跳调度独立出来，避免被其他任务影响 +heartbeatScheduler = Executors.newSingleThreadScheduledExecutor(); +HeartbeatConfig heartbeatConfig = config.getConfig(ConfigEnum.HEARTBEAT); +timerExecutor = ExecutorUtil.create("Timer", heartbeatConfig.getHeartbeat().getTimerExecutor()); +businessExecutor = ExecutorUtil.create("BusinessExecutor",Runtime.getRuntime().availableProcessors()); +listeningExecutorService = MoreExecutors.listeningDecorator(businessExecutor); +MatchMethodGenerator.initShrinkCharTbl(); +} +``` +7.1. 建立心跳线程, 原因是避免被其他任务影响. + +7.2 建立timerExecutor,线程数目默认为2. + +7.3 建立businessExecutor,线程数目为cpu数目. + +7.4 建立listeningExecutorService, 该ExecutorService将会进行任务的提交给businessExecutor + +7.5 调用io.mycat.mycat2.sqlparser.MatchMethodGenerator#initShrinkCharTbl方法.该方法只是对0-9a-zA-Z的字符进行映射.代码如下: + + +``` +static final byte[] shrinkCharTbl = new byte[96];//为了压缩hash字符映射空间，再次进行转义 +public static void initShrinkCharTbl () { + shrinkCharTbl[0] = 1;//从 $ 开始计算 + IntStream.rangeClosed('0', '9').forEach(c -> shrinkCharTbl[c-'$'] = (byte)(c-'0'+2)); + IntStream.rangeClosed('A', 'Z').forEach(c -> shrinkCharTbl[c-'$'] = (byte)(c-'A'+12)); + IntStream.rangeClosed('a', 'z').forEach(c -> shrinkCharTbl[c-'$'] = (byte)(c-'a'+12)); + shrinkCharTbl['_'-'$'] = (byte)38; +} +``` +8. 调用ProxyStarter的start,首先 是创建了NIOAcceptor,负责对请求进行处理.然后根据ClusterConfig的配置进行相应的处理. + + +``` +ClusterConfig clusterConfig = conf.getConfig(ConfigEnum.CLUSTER); +ClusterBean clusterBean = clusterConfig.getCluster(); +if (clusterBean.isEnable()) { + // 启动集群 + startCluster(runtime, clusterBean, acceptor); +} else { + // 未配置集群，直接启动 + startProxy(true); +} +``` + +9.接下来分析未配置集群的启动方式. + +9.1 首先通过ProxyRuntime获取到ProxyConfig(该对象是mycat.yml的封装)，mycat.yml的配置文件如下: + +``` +proxy: + ip: 0.0.0.0 + port: 8066 +``` +因此可以通过该类拿到启动端口和ip.因此传入NIOAcceptor进行监听. + +9.2 在io.mycat.proxy.NIOAcceptor#startServerChannel中,做了如下处理: + +9.2.1 首先检查ServerSocketChannel是否已经启动,如果已经启动,不进行后续处理. + +9.2.2 根据传入的ServerType做不同的处理,当前我们传入的值为MYCAT. 因此不进行处理. + +``` +if (serverType == ServerType.CLUSTER) { + adminSessionMan = new DefaultAdminSessionManager(); + ProxyRuntime.INSTANCE.setAdminSessionManager(adminSessionMan); + logger.info("opend cluster conmunite port on {}:{}", ip, port); +} else if (serverType == ServerType.LOAD_BALANCER){ + logger.info("opend load balance conmunite port on {}:{}", ip, port); + ProxyRuntime.INSTANCE.setProxySessionSessionManager(new ProxySessionManager()); + ProxyRuntime.INSTANCE.setLbSessionSessionManager(new LBSessionManager()); +} +``` + +9.2.3 调用io.mycat.proxy.NIOAcceptor#getServerSocketChannel,进行启动.代码如下: + + +``` +private void openServerChannel(Selector selector, String bindIp, int bindPort, ServerType serverType) + throws IOException { +final ServerSocketChannel serverChannel = ServerSocketChannel.open(); +final InetSocketAddress isa = new InetSocketAddress(bindIp, bindPort); +serverChannel.bind(isa); +serverChannel.configureBlocking(false); +serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true); +serverChannel.register(selector, SelectionKey.OP_ACCEPT, serverType); +if (serverType == ServerType.CLUSTER) { + logger.info("open cluster server port on {}:{}", bindIp, bindPort); + clusterServerSocketChannel = serverChannel; +} else if (serverType == ServerType.LOAD_BALANCER) { + logger.info("open load balance server port on {}:{}", bindIp, bindPort); + loadBalanceServerSocketChannel = serverChannel; +} else { + logger.info("open proxy server port on {}:{}", bindIp, bindPort); + proxyServerSocketChannel = serverChannel; +} +} +``` + +9.4 调用io.mycat.mycat2.ProxyStarter#startReactor,进行MycatReactorThread的启动.该线程负责对请求进行处理. + +9.5 加载配置文件信息,该方法在ROOT_PATH目录下创建了prepare和archive两个文件夹,并加载了replica-index.yml,datasource.yml,schema.yml,最后调用了AnnotationProcessor#getInstance 进行初始化. + +9.5.1 创建DynamicAnnotationManager. + +9.5.2 对AnnotationProcessor.class.getClassLoader().getResource("") 的路径进行监听.当文件目录有变化时会回调io.mycat.mycat2.sqlannotations.AnnotationProcessor#listen方法.代码如下: + + +``` +public static void listen() { +try { +while (true) { + WatchKey key = watcher.take();//todo 线程复用,用 poll比较好? + boolean flag = false; + for (WatchEvent event: key.pollEvents()) { + String str = event.context().toString(); + if ("actions.yml".equals(str)|| "annotations.yml".equals(str)) { + flag=true; + break; + } + } + if (flag){ + System.out.println("动态注解更新次数" + count.incrementAndGet()); + init(); + } + boolean valid = key.reset(); + if (!valid) { + break; + } + +} +} catch (Exception e) { +e.printStackTrace(); +} +} +``` + +==可以看到,当actions.yml或者annotations.yml变化时,就会重新调用init方法,从而对DynamicAnnotationManager进行修改.== + + +9.6 分别对datasource.yml 和 schema.yml 进行加载. + +9.6.1 对MySQLRepBean进行初始化.该bean是对datasource.yml的封装.datasource.yml如下所示: + + +``` +replicas: + - name: test # 复制组 名称 必须唯一 + repType: MASTER_SLAVE # 复制类型 + switchType: SWITCH # 切换类型 + balanceType: BALANCE_ALL_READ # 读写分离类型 + mysqls: + - hostName: mysql-01 # mysql 主机名 + ip: 127.0.0.1 # ip + port: 3306 # port + user: root # 用户名 + password: root # 密码 + minCon: 1 # 最小连接 + maxCon: 10 # 最大连接 + maxRetryCount: 3 # 连接重试次数 + +``` + + +``` +conf.getMysqlRepMap().forEach((repName, repBean) -> { + repBean.initMaster(); + repBean.getMetaBeans().forEach(metaBean -> metaBean.prepareHeartBeat(repBean, repBean.getDataSourceInitStatus())); +}); +``` + +9.6.2 调用io.mycat.mycat2.beans.MySQLRepBean#initMaster, 做了如下处理: + +首先加载replica-index.yml,获取replica name 对应的index，并对MySQLRepBean中的metaBeans进行赋值,完成对mysqls 的封装. + +之后调用MySQLMetaBean的prepareHeartBeat方法. +完成 + + +9.7 ==调用io.mycat.proxy.ProxyRuntime#startHeartBeatScheduler,启动heartbeatScheduler线程.该线程会每10000 ms 调用io.mycat.proxy.ProxyRuntime#replicaHeartbeat.== 心跳的配置在heartbeat.yml中,默认配置如下: + + +``` +heartbeat: + timerExecutor: 2 + replicaHeartbeatPeriod: 10000 + replicaIdleCheckPeriod: 2000 + idleTimeout: 2000 + processorCheckPeriod: 2000 + minSwitchtimeInterval: 120000 +``` + +9.7.1 在io.mycat.proxy.ProxyRuntime#replicaHeartbeat,方法中代码如下: + + +``` +private Runnable replicaHeartbeat() { +return ()->{ +ProxyReactorThread reactor = getReactorThreads()[ThreadLocalRandom.current().nextInt(getReactorThreads().length)]; +reactor.addNIOJob(()-> config.getMysqlRepMap().values().stream().forEach(f -> f.doHeartbeat())); +}; +} +``` + +最终会调用io.mycat.mycat2.beans.heartbeat.MySQLHeartbeat#heartbeat. + + +9.8 对cluster的配置进行处理.代码如下: + + +``` +BalancerConfig balancerConfig = conf.getConfig(ConfigEnum.BALANCER); +BalancerBean balancerBean = balancerConfig.getBalancer(); +// 集群模式下才开启负载均衡服务 +if (clusterBean.isEnable() && balancerBean.isEnable()) { + runtime.getAcceptor().startServerChannel(balancerBean.getIp(), balancerBean.getPort(), ServerType.LOAD_BALANCER); +} +``` +