Jedis 参数异常引发服务雪崩案例分析

<redis-cluster name="redisCluster" timeout="3000" maxRedirections="6"> // 最大重试次数为6    <properties>        <property name="maxTotal" value="20" />        <property name="maxIdle" value="20" />        <property name="minIdle" value="2" />    </properties></redis-cluster>

public class JedisCluster extends BinaryJedisCluster implements JedisCommands,    MultiKeyJedisClusterCommands, JedisClusterScriptingCommands {   @Override  public String set(final String key, final String value, final String nxxx, final String expx,      final long time) {    return new JedisClusterCommand<String>(connectionHandler, maxAttempts) {      @Override      public String execute(Jedis connection) {        // 真正发送命令的逻辑        return connection.set(key, value, nxxx, expx, time);      }    }.run(key); // 通过run触发命令的执行  }}  public abstract class JedisClusterCommand<T> {   public abstract T execute(Jedis connection);   public T run(String key) {    // 执行带有重试机制的方法    return runWithRetries(SafeEncoder.encode(key), this.maxAttempts, false, false);  }}  public abstract class JedisClusterCommand<T> {   private T runWithRetries(byte[] key, int attempts, boolean tryRandomNode, boolean asking) {     Jedis connection = null;    try {       if (asking) {        // 省略相关的代码逻辑      } else {        if (tryRandomNode) {          connection = connectionHandler.getConnection();        } else {          // 1、尝试获取连接          connection = connectionHandler.getConnectionFromSlot(JedisClusterCRC16.getSlot(key));        }      }      // 2、执行JedisClusterCommand封装的execute命令      return execute(connection);     } catch (JedisNoReachableClusterNodeException jnrcne) {      throw jnrcne;    } catch (JedisConnectionException jce) {      // 省略代码    } finally {      releaseConnection(connection);    }  }}

public final class JedisClusterCRC16 {   public static int getSlot(byte[] key) {    int s = -1;    int e = -1;    boolean sFound = false;    for (int i = 0; i < key.length; i++) {      if (key[i] == '{' && !sFound) {        s = i;        sFound = true;      }      if (key[i] == '}' && sFound) {        e = i;        break;      }    }    if (s > -1 && e > -1 && e != s + 1) {      return getCRC16(key, s + 1, e) & (16384 - 1);    }    return getCRC16(key) & (16384 - 1);  }}

public class JedisSlotBasedConnectionHandler extends JedisClusterConnectionHandler {   @Override  public Jedis getConnectionFromSlot(int slot) {    JedisPool connectionPool = cache.getSlotPool(slot);    if (connectionPool != null) {      // 尝试获取连接      return connectionPool.getResource();    } else {      renewSlotCache();      connectionPool = cache.getSlotPool(slot);      if (connectionPool != null) {        return connectionPool.getResource();      } else {        return getConnection();      }    }  }} class JedisFactory implements PooledObjectFactory<Jedis> {   @Override  public PooledObject<Jedis> makeObject() throws Exception {    // 1、创建Jedis连接    final HostAndPort hostAndPort = this.hostAndPort.get();    final Jedis jedis = new Jedis(hostAndPort.getHost(), hostAndPort.getPort(), connectionTimeout,        soTimeout, ssl, sslSocketFactory, sslParameters, hostnameVerifier);     try {       // 2、尝试进行连接      jedis.connect();    } catch (JedisException je) {      jedis.close();      throw je;    }     return new DefaultPooledObject<Jedis>(jedis);   }} public class Connection implements Closeable {      public void connect() {    if (!isConnected()) {      try {        socket = new Socket();        socket.setReuseAddress(true);        socket.setKeepAlive(true); // Will monitor the TCP connection is        socket.setTcpNoDelay(true); // Socket buffer Whetherclosed, to        socket.setSoLinger(true, 0); // Control calls close () method,         // 1、设置连接超时时间 DEFAULT_TIMEOUT = 2000;        socket.connect(new InetSocketAddress(host, port), connectionTimeout);        // 2、设置读取超时时间        socket.setSoTimeout(soTimeout);         outputStream = new RedisOutputStream(socket.getOutputStream());        inputStream = new RedisInputStream(socket.getInputStream());      } catch (IOException ex) {        broken = true;        throw new JedisConnectionException(ex);      }    }  }}

public class Connection implements Closeable {   protected Connection sendCommand(final Command cmd, final byte[]... args) {    try {      // 1、必要时尝试连接      connect();      // 2、发送命令      Protocol.sendCommand(outputStream, cmd, args);      pipelinedCommands++;      return this;    } catch (JedisConnectionException ex) {      broken = true;      throw ex;    }  }   private static void sendCommand(final RedisOutputStream os, final byte[] command,      final byte[]... args) {    try {      // 按照redis的命令格式发送数据      os.write(ASTERISK_BYTE);      os.writeIntCrLf(args.length + 1);      os.write(DOLLAR_BYTE);      os.writeIntCrLf(command.length);      os.write(command);      os.writeCrLf();       for (final byte[] arg : args) {        os.write(DOLLAR_BYTE);        os.writeIntCrLf(arg.length);        os.write(arg);        os.writeCrLf();      }    } catch (IOException e) {      throw new JedisConnectionException(e);    }  }}

public abstract class JedisClusterCommand<T> {   private T runWithRetries(byte[] key, int attempts, boolean tryRandomNode, boolean asking) {     Jedis connection = null;    try {       if (asking) {      } else {        if (tryRandomNode) {          connection = connectionHandler.getConnection();        } else {          // 1、尝试获取连接          connection = connectionHandler.getConnectionFromSlot(JedisClusterCRC16.getSlot(key));        }      }      // 2、通过连接执行命令      return execute(connection);     } catch (JedisNoReachableClusterNodeException jnrcne) {      throw jnrcne;    } catch (JedisConnectionException jce) {      releaseConnection(connection);      connection = null;      // 4、重试到最后一次抛出异常      if (attempts <= 1) {        this.connectionHandler.renewSlotCache();         throw jce;      }      // 3、进行第一轮重试      return runWithRetries(key, attempts - 1, tryRandomNode, asking);    } finally {      releaseConnection(connection);    }  }}