Joseph Doherty
2.7 KiB
Worker Process Launcher
The gateway uses WorkerProcessLauncher to validate and start one worker
process for a gateway session. The launcher owns process start semantics only;
pipe handshaking and WorkerReady validation remain part of the worker client
startup path.
Launch Inputs
WorkerProcessLaunchRequest carries the per-session bootstrap values:
SessionId,PipeName,ProtocolVersion,Nonce,- optional
PipeReservationcleanup handle.
The launcher passes SessionId, PipeName, and ProtocolVersion as command
line arguments:
--session-id <sessionId> --pipe-name <pipeName> --protocol-version <version>
The launcher sets the nonce through the MXGATEWAY_WORKER_NONCE environment
variable. The nonce is not included in WorkerProcessCommandLine so logs and
diagnostics can report the launch command without exposing the secret.
Validation And Cleanup
Before starting the process, the launcher validates that the configured worker
path exists, has a .exe extension, contains a valid Windows Portable
Executable header, and matches the configured RequiredArchitecture.
After the process starts, IWorkerStartupProbe waits for startup readiness.
The default probe only verifies that the worker did not exit immediately. The
worker client replaces this probe when pipe connection, hello, and
WorkerReady handling are implemented.
Startup probing uses a bounded Polly retry policy. The gateway starts the worker
process once, then retries only transient startup-probe failures while the
process remains alive. The policy is configured by
WorkerOptions.StartupProbeRetryAttempts and
WorkerOptions.StartupProbeRetryDelayMilliseconds; the retry counter is
recorded as mxgateway.retries.attempted with area=worker_startup.
The launcher also passes
MXGATEWAY_WORKER_PIPE_CONNECT_ATTEMPT_TIMEOUT_MS to the worker process from
WorkerOptions.PipeConnectAttemptTimeoutMilliseconds. The worker uses that
value as the per-attempt named-pipe connect timeout inside its own bounded
Polly retry loop.
If startup fails or exceeds WorkerOptions.StartupTimeoutSeconds, the launcher
kills the worker process tree, disposes the process handle, disposes the
optional pipe reservation, records a worker kill metric, and reports a
WorkerProcessLaunchException.
Verification
Run the focused launcher tests after changing process launch behavior:
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter WorkerProcessLauncherTests
Run the gateway build because the launcher is part of MxGateway.Server:
dotnet build src/MxGateway.Server/MxGateway.Server.csproj