grpc/grpc-java · info · UnsupportedOperationException

Unsupported operation setPerformancePreferences()

Error message

Unsupported operation setPerformancePreferences()

What it means

setPerformancePreferences() hints at TCP connection parameters (connection time vs latency vs bandwidth); the JVM/Android never fully implemented it and it is meaningless for a Unix domain socket. UdsSocket throws UnsupportedOperationException unconditionally.

Solutions

1. Drop the call for UDS channels — performance preferences are a no-op hint even on TCP and are unsupported here
2. Tune performance at the gRPC level (message sizes, compression, executor threads) instead of socket hints
3. Remove setPerformancePreferences from shared socket setup utilities

Example fix

// before
socket.setPerformancePreferences(0, 2, 1);
// after
// no socket-level hint for UDS; tune at channel level instead

if (socket instanceof io.grpc.android.UdsSocket) return; // skip performance preferences

static boolean acceptsPerfPreferences(java.net.Socket s) { return !(s instanceof io.grpc.android.UdsSocket); }

When it happens

Trigger: Direct call to UdsSocket.setPerformancePreferences(int,int,int), or legacy socket-tuning code migrated alongside a UDS gRPC channel.

Common situations: Copying old TCP tuning snippets into UDS channel setup; performance-profiling frameworks that apply preference hints to every socket.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• getChannel() not supported
• getInetAddress() not supported
• OkHttpChannelBuilder not found on the classpath
• Unsupported operation getKeepAlive()
• Unsupported operation getLocalAddress()

AI-assisted analysis of grpc/grpc-java@64daddc1f3 (2026-09-08). Data as JSON: /api/errors/06f2d1ba6682d15a. Report an issue: GitHub.

Appendix: source

Thrown at android/src/main/java/io/grpc/android/UdsSocket.java:245

  @Override
  public void sendUrgentData(int data) {
    throw new UnsupportedOperationException("Unsupported operation sendUrgentData()");
  }

  @Override
  public void setKeepAlive(boolean on) {
    throw new UnsupportedOperationException("Unsupported operation setKeepAlive()");
  }

  @Override
  public void setOOBInline(boolean on) {
    throw new UnsupportedOperationException("Unsupported operation setOOBInline()");
  }

  @Override
  public void setPerformancePreferences(int connectionTime, int latency, int bandwidth) {
    throw new UnsupportedOperationException("Unsupported operation setPerformancePreferences()");
  }

  @Override
  public void setReceiveBufferSize(int size) throws SocketException {
    try {
      localSocket.setReceiveBufferSize(size);
    } catch (IOException e) {
      throw toSocketException(e);
    }
  }

  @Override
  public void setReuseAddress(boolean on) {
    throw new UnsupportedOperationException("Unsupported operation setReuseAddress()");
  }

  @Override
  public void setSendBufferSize(int size) throws SocketException {

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