Talk nacos of MysqlHealthCheckProcessor

sequence

In this paper, we look nacos of MysqlHealthCheckProcessor

MysqlHealthCheckProcessor

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/healthcheck/MysqlHealthCheckProcessor.java

@Component
public class MysqlHealthCheckProcessor implements HealthCheckProcessor {

    @Autowired
    private HealthCheckCommon healthCheckCommon;

    @Autowired
    private SwitchDomain switchDomain;

    public static final int CONNECT_TIMEOUT_MS = 500;

    private static final String CHECK_MYSQL_MASTER_SQL = "show global variables where variable_name='read_only'";
    private static final String MYSQL_SLAVE_READONLY = "ON";

    private static ConcurrentMap<String, Connection> CONNECTION_POOL
            = new ConcurrentHashMap<String, Connection>();

    private static ExecutorService EXECUTOR;

    static {

        int processorCount = Runtime.getRuntime().availableProcessors();
        EXECUTOR
                = Executors.newFixedThreadPool(processorCount <= 1 ? 1 : processorCount / 2,
                new ThreadFactory() {
                    @Override
                    public Thread newThread(Runnable r) {
                        Thread thread = new Thread(r);
                        thread.setDaemon(true);
                        thread.setName("com.nacos.mysql.checker");
                        return thread;
                    }
                }
        );
    }

    public MysqlHealthCheckProcessor() {
    }

    @Override
    public String getType() {
        return "MYSQL";
    }

    @Override
    public void process(HealthCheckTask task) {
        List<Instance> ips = task.getCluster().allIPs(false);

        SRV_LOG.debug("mysql check, ips:" + ips);
        if (CollectionUtils.isEmpty(ips)) {
            return;
        }

        for (Instance ip : ips) {
            try {

                if (ip.isMarked()) {
                    if (SRV_LOG.isDebugEnabled()) {
                        SRV_LOG.debug("mysql check, ip is marked as to skip health check, ip: {}", ip.getIp());
                    }
                    continue;
                }

                if (!ip.markChecking()) {
                    SRV_LOG.warn("mysql check started before last one finished, service: {}:{}:{}",
                        task.getCluster().getService().getName(), task.getCluster().getName(), ip.getIp());

                    healthCheckCommon.reEvaluateCheckRT(task.getCheckRTNormalized() * 2, task, switchDomain.getMysqlHealthParams());
                    continue;
                }

                EXECUTOR.execute(new MysqlCheckTask(ip, task));
                MetricsMonitor.getMysqlHealthCheckMonitor().incrementAndGet();
            } catch (Exception e) {
                ip.setCheckRT(switchDomain.getMysqlHealthParams().getMax());
                healthCheckCommon.checkFail(ip, task, "mysql:error:" + e.getMessage());
                healthCheckCommon.reEvaluateCheckRT(switchDomain.getMysqlHealthParams().getMax(), task, switchDomain.getMysqlHealthParams());
            }
        }
    }

    //......
}
复制代码

• MysqlHealthCheckProcessor realized HealthCheckProcessor interface that getType method returns MYSQL; its process method will traverse instances, for non-implementation of healthCheckCommon.reEvaluateCheckRT markChecking will, for skip marked, for the markChecking will create MysqlCheckTask submitted to the Executive EXECUTOR

MysqlCheckTask

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/healthcheck/MysqlHealthCheckProcessor.java

    private class MysqlCheckTask implements Runnable {
        private Instance ip;
        private HealthCheckTask task;
        private long startTime = System.currentTimeMillis();

        public MysqlCheckTask(Instance ip, HealthCheckTask task) {
            this.ip = ip;
            this.task = task;
        }

        @Override
        public void run() {

            Statement statement = null;
            ResultSet resultSet = null;

            try {

                Cluster cluster = task.getCluster();
                String key = cluster.getService().getName() + ":" + cluster.getName() + ":" + ip.getIp() + ":" + ip.getPort();
                Connection connection = CONNECTION_POOL.get(key);
                AbstractHealthChecker.Mysql config = (AbstractHealthChecker.Mysql) cluster.getHealthChecker();

                if (connection == null || connection.isClosed()) {
                    MysqlDataSource dataSource = new MysqlDataSource();
                    dataSource.setConnectTimeout(CONNECT_TIMEOUT_MS);
                    dataSource.setSocketTimeout(CONNECT_TIMEOUT_MS);
                    dataSource.setUser(config.getUser());
                    dataSource.setPassword(config.getPwd());
                    dataSource.setLoginTimeout(1);

                    dataSource.setServerName(ip.getIp());
                    dataSource.setPort(ip.getPort());

                    connection = dataSource.getConnection();
                    CONNECTION_POOL.put(key, connection);
                }

                statement = connection.createStatement();
                statement.setQueryTimeout(1);

                resultSet = statement.executeQuery(config.getCmd());
                int resultColumnIndex = 2;

                if (CHECK_MYSQL_MASTER_SQL.equals(config.getCmd())) {
                    resultSet.next();
                    if (MYSQL_SLAVE_READONLY.equals(resultSet.getString(resultColumnIndex))) {
                        throw new IllegalStateException("current node is slave!");
                    }
                }

                healthCheckCommon.checkOK(ip, task, "mysql:+ok");
                healthCheckCommon.reEvaluateCheckRT(System.currentTimeMillis() - startTime, task, switchDomain.getMysqlHealthParams());
            } catch (SQLException e) {
                // fail immediately
                healthCheckCommon.checkFailNow(ip, task, "mysql:" + e.getMessage());
                healthCheckCommon.reEvaluateCheckRT(switchDomain.getHttpHealthParams().getMax(), task, switchDomain.getMysqlHealthParams());
            } catch (Throwable t) {
                Throwable cause = t;
                int maxStackDepth = 50;
                for (int deepth = 0; deepth < maxStackDepth && cause != null; deepth++) {
                    if (cause instanceof SocketTimeoutException
                            || cause instanceof ConnectTimeoutException
                            || cause instanceof TimeoutException
                            || cause.getCause() instanceof TimeoutException) {

                        healthCheckCommon.checkFail(ip, task, "mysql:timeout:" + cause.getMessage());
                        healthCheckCommon.reEvaluateCheckRT(task.getCheckRTNormalized() * 2, task, switchDomain.getMysqlHealthParams());
                        return;
                    }

                    cause = cause.getCause();
                }

                // connection error, probably not reachable
                healthCheckCommon.checkFail(ip, task, "mysql:error:" + t.getMessage());
                healthCheckCommon.reEvaluateCheckRT(switchDomain.getMysqlHealthParams().getMax(), task, switchDomain.getMysqlHealthParams());
            } finally {
                ip.setCheckRT(System.currentTimeMillis() - startTime);
                if (statement != null) {
                    try {
                        statement.close();
                    } catch (SQLException e) {
                        Loggers.SRV_LOG.error("[MYSQL-CHECK] failed to close statement:" + statement, e);
                    }
                }
                if (resultSet != null) {
                    try {
                        resultSet.close();
                    } catch (SQLException e) {
                        Loggers.SRV_LOG.error("[MYSQL-CHECK] failed to close resultSet:" + resultSet, e);
                    }
                }
            }
        }
    }
复制代码

• MysqlCheckTask method implements Runnable whose run method gets the connection from the specified instance CONNECTION_POOL, if the connection is re-created MysqlDataSource is null or is closed and getConnection () to put CONNECTION_POOL; after obtaining connection performs config.getCmd () specified query, and then returns the performed result according healthCheckCommon.checkOK or healthCheckCommon.checkFailNow or anomalies, healthCheckCommon.checkFail operation

summary

MysqlHealthCheckProcessor realized HealthCheckProcessor interface that getType method returns MYSQL; its process method will traverse instances, for non-implementation of healthCheckCommon.reEvaluateCheckRT markChecking will, for skip marked, for the markChecking will create MysqlCheckTask submitted to the Executive EXECUTOR

doc

• MysqlHealthCheckProcessor