4 - Protocol Layer on Apache Dubbo

4-1 - Unsupported Protocol

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

This situation may occur in scenarios with a custom Protocol. Dubbo’s SPI mechanism cannot find the Protocol specified in the URL.

Troubleshooting and Resolution Steps

Ensure that the Consumer has the dependencies for the Protocol used by the server.
Confirm that the name of the SPI configuration file for the Protocol’s dependency package is correct.

See also
Overview of Dubbo SPI
Protocol Extension Description

4-2 - An Initial Error Occurred for the Serialization Optimizer

Mon, 01 Jan 0001 00:00:00 +0000

Possible Reasons

The current serialization configuration uses Kryo and FST.

Troubleshooting and Resolution Steps

Kryo and FST Serialization

4-3 - Interface reference call failed

Mon, 01 Jan 0001 00:00:00 +0000

Possible Reasons

The exposed service interface or method was not found based on the specified protocol parameters.

Troubleshooting and Resolution Steps

You can confirm whether the server exists based on the interface URL and method name.

4-4 - Unsafe Serialization Method

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Currently using an unsafe serializer, which is not recommended. The specific configuration is: serialization="java"

Java serialization is unsafe. The Dubbo team does not recommend anyone to use it. If you still want to use it, please follow JEP 290 to set up a serialization filter to prevent deserialization leaks.

Troubleshooting and Resolution Steps

Modify the serialization parameter value. Change the serialization parameter value within the protocol to something else, such as hessian2, fastjson2, etc.

4-5 - Stream Closure Exception

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Prompt information that does not affect the execution result of the program.

Troubleshooting and Resolution Steps

You can use some third-party tools or jstack [PID] > jstack.log to analyze stack information for diagnosis.

4-6 - Deserialization Failure

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

This occurs when using a custom serialization method, and an error happens during the use of the custom SPI org.apache.dubbo.common.serialize.Serialization serialization method.

Troubleshooting and Resolution Steps

Stack trace information can be analyzed using some third-party tools or by using jstack [PID] > jstack.log to obtain the content of the object that caused the error, and then modify it in conjunction with the custom implementation.

Refer to Serialization Extension

4-7 - Error Occurred When Closing Client

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

An error occurs during the close or destroy of various Connect Clients, which does not affect the final outcome.

Troubleshooting and Resolution Steps

Stack trace information can be analyzed using some third-party tools or by using jstack [PID] > jstack.log for diagnosis.

4-8 - Error occurred when shutting down the server

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Similar to 4-7, this occurs during shutdown.

Troubleshooting and Resolution Steps

You can analyze the stack trace information using some third-party tools or jstack [PID] > jstack.log for locating the issue.

4-9 - Parsing Failed

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Generally, it is due to parameter values not conforming to the rules, resulting in errors during conversion. For example:

String timeoutString = httpMetadata.headers().getFirst(TripleHeaderEnum.SERVICE_TIMEOUT.getHeader());
Long timeout = Long.parseLong(timeoutString);

Long timeout = GrpcUtils.parseTimeoutToMills(timeoutString);
invocation.put(CommonConstants.TIMEOUT_KEY, timeout);

Troubleshooting and Resolution Steps

Modify the corresponding configuration according to the key name indicated in the stack information to meet the conversion rules.

4-10 - Triple serialization result failure

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Generally an internal error. Seen in three types of log formats:

An exception occurs during serialization and sending data, log format: Serialize triple request failed, service=%s method=%s
Triggered when receiving the response’s reset code, log format: Triple Client received remote reset errorCode=xxx
Triggered when an exception occurs while processing the response, log format: Meet Exception on ClientResponseHandler, status code is:xxx

Troubleshooting and Resolution Steps

For the first type of error, it occurs during the call to {service}#{method}, specifically correlating to sendMessage, and this log appears simultaneously with java.util.concurrent.ExecutionException: org.apache.dubbo.rpc.StatusRpcException: INTERNAL : Serialize request failed. Check if the custom classes in the parameters of the {method} are implementing the serialization interface, which may lead to serialization failure.

4-11 - Request initiation failed

Mon, 01 Jan 0001 00:00:00 +0000

Possible Reasons

The service provider has been shut down.
The caller’s IP is not in the service provider’s whitelist.
The specific service address requested does not exist.

Troubleshooting and Resolution Steps

Check the startup status of the service provider.
Check or use third-party tools to test if the network environment is properly connected.
Based on the stack’s serviceName, check or simulate the call in the management platform to see if it works properly.

4-12 - Failed to create Triple stream

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Generally, it is an internal error.

Troubleshooting and Resolution Steps

You can analyze the stack information using some third-party tools or by executing jstack [PID] > jstack.log for diagnosis.

Please also submit an issue in the community.

4-13 - Server Timeout

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

The server’s logic processing takes a relatively long time.
The server is under heavy load and cannot respond.
The current timeout parameter settings differ significantly from the actual situation.

Troubleshooting and Resolution Steps

Check for long processing times based on the interface name.
Monitor server status and the service invocation situation on the server side.
Try increasing the timeout parameters somewhat.

4-14 - Response Result Failure

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

The server pipeline may be temporarily disconnected due to network reasons.
The currently used version is low or check the current parameter configuration to see if send.reconnect=true is enabled, which defaults to true in higher versions.

Troubleshooting and Resolution Steps

Check if the direct connection network is smooth and whether there are packet loss issues.
Check the above parameter values or try using a higher version.

4-15 - Client Stream Listener

Mon, 01 Jan 0001 00:00:00 +0000

Possible Reasons

After receiving a response from the server, the client stream listener outputs this information as a notification.

Troubleshooting and Resolution Steps

4-16 - Service is closed

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Continuing to call org.apache.dubbo.rpc.protocol.tri.service.TriHealthImpl#enterTerminalState or org.apache.dubbo.rpc.protocol.ReferenceCountInvokerWrapper#invoke in an erroneous state, while the call is already in terminal or destroy state.

Troubleshooting and Resolution Steps

Multiple calls to the above methods will trigger reminders. Generally used only for unit testing.

4-17 - Errors occur when shutting down all callers

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Generally, it is an internal error.

Troubleshooting and Resolution Steps

You can analyze the stack information using some third-party tools or jstack [PID] > jstack.log for diagnosis.

Also, please submit an issue in the community.

4-18 - Unable to obtain service model from the call

Mon, 01 Jan 0001 00:00:00 +0000

Possible Reasons

Currently initialized by default only for unit test scenarios.

Troubleshooting and Resolution Steps

4-19 - Possible errors in parameter values

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

This error code indicates that the parameter values may no longer be correct.

Currently, this occurs when multiple ports are being listened to simultaneously under the same protocol. Due to design limitations, a single protocol can only listen on one port; otherwise, the port configuration will be overwritten.

Troubleshooting and Resolution Steps

Adjust the listening relationship between the protocol and ports.

The meaning of this error code has been adjusted. For the errors related to this error code in Dubbo versions 3.1.4, 3.2.0-beta.3, and earlier, please refer to the error code 0-2 .

4-20 - Data Decoding Failure

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

Occurs only during the decoding phase, possibly due to a mismatch between the Dubbo versions of the service provider and the caller.

Troubleshooting and Resolution Steps

Check the current Dubbo version in use, and try to keep it consistent or compatible with a higher version.

4-21 - Unsafe serialization data detected

Mon, 01 Jan 0001 00:00:00 +0000

Possible Causes

The current server may be under attack, or the built-in class checking logic of Dubbo has not scanned the classes you defined.

Troubleshooting and Resolution Steps

If the request source is an attack source, please promptly reinforce security.
If the request source is expected, declare the class names you are using in the security/serialize.allowlist resource file, and Dubbo will automatically load them into the allowlist. Please refer to the Class Checking Mechanism article.

Currently, Dubbo can operate in monitoring mode and restriction mode. Monitoring mode only logs, without interception; restriction mode will perform interception.