grpc protocol_error ai_generated true

INVALID_ARGUMENT: unknown field 42 in message type google.protobuf.Timestamp

ID: grpc/protobuf-unknown-field-rejected

Also available as: JSON · Markdown · 中文
85%Fix Rate
82%Confidence
1Evidence
2024-09-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
protobuf v25.0 active — — —
gRPC v1.64.0 active — — —
gRPC-Web v1.5.0 active — — —

Root Cause

gRPC server with protobuf strict validation (e.g., 'protojson.DiscardUnknown=false' or gRPC-Web) rejects a request containing an unknown field number in a protobuf message.

generic

中文

启用protobuf严格验证（如'protojson.DiscardUnknown=false'或gRPC-Web）的gRPC服务器拒绝包含protobuf消息中未知字段编号的请求。

Official Documentation

https://protobuf.dev/programming-guides/proto3/#unknowns

Workarounds

  1. 90% success Update the client to remove the unknown field: in protobuf JSON, omit field 42 from the request payload; for gRPC-Web, ensure the protobuf binary doesn't include extra fields by regenerating stubs from the same .proto file. 
    Update the client to remove the unknown field: in protobuf JSON, omit field 42 from the request payload; for gRPC-Web, ensure the protobuf binary doesn't include extra fields by regenerating stubs from the same .proto file.
  2. 85% success Update the server to accept the unknown field: add field 42 to the protobuf definition and regenerate server code; deploy the updated server binary to match the client schema. 
    Update the server to accept the unknown field: add field 42 to the protobuf definition and regenerate server code; deploy the updated server binary to match the client schema.
  3. 75% success Use a custom protobuf parser with 'protojson.UnmarshalOptions{DiscardUnknown: true}' in Go or equivalent in other languages to ignore unknown fields on the server side, but document the risk. 
    Use a custom protobuf parser with 'protojson.UnmarshalOptions{DiscardUnknown: true}' in Go or equivalent in other languages to ignore unknown fields on the server side, but document the risk.

中文步骤

  1. 更新客户端以移除未知字段：在protobuf JSON中，从请求负载中省略字段42；对于gRPC-Web，通过从相同.proto文件重新生成存根，确保protobuf二进制文件不包含额外字段。
  2. 更新服务器以接受未知字段：将字段42添加到protobuf定义并重新生成服务器代码；部署更新的服务器二进制文件以匹配客户端架构。
  3. 使用自定义protobuf解析器，在Go中设置'protojson.UnmarshalOptions{DiscardUnknown: true}'或其他语言中的等效选项，以忽略服务器端的未知字段，但需记录风险。

Dead Ends

Common approaches that don't work:

  1. 90% fail

    Adding a new field to the protobuf definition without updating the server binary fails because the server still lacks the field descriptor.

  2. 99% fail

    Ignoring the error and retrying the same request repeatedly doesn't change the server's validation; the error persists until the unknown field is removed.

  3. 60% fail

    Disabling server-side validation entirely ('protojson.DiscardUnknown=true') may expose the server to malicious payloads or data corruption from future schema changes.