apache/hadoop · error · SaslException

Received malformed response length

Error message

Received malformed response length

What it means

Error "Received malformed response length" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslRpcClient.java:393

      ByteBuffer bb = ipcStreams.readResponse();

      RpcWritable.Buffer saslPacket = RpcWritable.Buffer.wrap(bb);
      RpcResponseHeaderProto header =
          saslPacket.getValue(RpcResponseHeaderProto.getDefaultInstance());
      switch (header.getStatus()) {
        case ERROR: // might get a RPC error during 
        case FATAL:
          throw new RemoteException(header.getExceptionClassName(),
                                    header.getErrorMsg());
        default: break;
      }
      if (header.getCallId() != AuthProtocol.SASL.callId) {
        throw new SaslException("Non-SASL response during negotiation");
      }
      RpcSaslProto saslMessage =
          saslPacket.getValue(RpcSaslProto.getDefaultInstance());
      if (saslPacket.remaining() > 0) {
        throw new SaslException("Received malformed response length");
      }
      // handle sasl negotiation process
      RpcSaslProto.Builder response = null;
      switch (saslMessage.getState()) {
        case NEGOTIATE: {
          // create a compatible SASL client, throws if no supported auths
          SaslAuth saslAuthType = selectSaslClient(saslMessage.getAuthsList());
          // define auth being attempted, caller can query if connect fails
          authMethod = AuthMethod.valueOf(saslAuthType.getMethod());
          
          byte[] responseToken = null;
          if (authMethod == AuthMethod.SIMPLE) { // switching to SIMPLE
            done = true; // not going to wait for success ack
          } else {
            byte[] challengeToken = null;
            if (saslAuthType.hasChallenge()) {
              // server provided the first challenge
              challengeToken = saslAuthType.getChallenge().toByteArray();

View on GitHub (pinned to 2add963021)

Solutions

1. Check for corrupted RPC traffic; the SASL response length could not be parsed.
2. Verify no non-RPC service or proxy is writing to the connection.
3. Align client and server versions; persistent failures warrant a packet capture to identify the sender.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslRpcClient.java:393 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/6e3c27ce8cc059ca. Report an issue: GitHub.