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本文主要研究一下nacos的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实现了HealthCheckProcessor接口，其getType方法返回的是MYSQL；其process方法会遍历instances，对于非markChecking的会执行healthCheckCommon.reEvaluateCheckRT，对于marked的直接跳过，对于markChecking的会创建MysqlCheckTask提交给EXECUTOR执行
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实现了Runnable方法，其run方法会从CONNECTION_POOL获取指定实例的connection，如果connection为null或者是closed的则重新创建MysqlDataSource并getConnection()放入到CONNECTION_POOL；获取到connection之后会执行config.getCmd()指定的查询，然后根据返回结果或异常情况执行healthCheckCommon.checkOK或者healthCheckCommon.checkFailNow、healthCheckCommon.checkFail操作
小结
MysqlHealthCheckProcessor实现了HealthCheckProcessor接口，其getType方法返回的是MYSQL；其process方法会遍历instances，对于非markChecking的会执行healthCheckCommon.reEvaluateCheckRT，对于marked的直接跳过，对于markChecking的会创建MysqlCheckTask提交给EXECUTOR执行
