Joseph Doherty
ff397b27be
WorkerProcessStartedProbe only checks HasExited and throws a non-retryable WorkerProcessLaunchException, so StartupProbeRetryAttempts and StartupProbeRetryDelayMilliseconds configured a Polly retry that no shipped probe could trigger. Real readiness is WorkerClient's WorkerReady handshake under the same StartupTimeoutSeconds budget, so the probe now runs once and the two options, their validation, the Polly pipeline (and the server's now unused Polly.Core reference) and their docs are removed. A stale value in configuration is ignored by the binder. Tests: WorkerProcessLauncherTests.LaunchAsync_WhenStartupProbeFails_DoesNotRetryTheProbe, WorkerOptions_HasNoStartupProbeRetryOptions (both fail on the old code).
3.7 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.
All launch-variable names live in the shared Contracts
WorkerLaunchEnvironment class and are consumed by both the launcher and the
worker. The launcher always exports all six values:
| Environment variable | Gateway source | Worker default when missing/invalid |
|---|---|---|
MXGATEWAY_WORKER_NONCE |
WorkerProcessLaunchRequest.Nonce |
None; bootstrap fails because the nonce is required |
MXGATEWAY_WORKER_PIPE_CONNECT_ATTEMPT_TIMEOUT_MS |
MxGateway:Worker:PipeConnectAttemptTimeoutMilliseconds |
2000 ms |
MXGATEWAY_WORKER_WRITE_COMPLETION_WAIT_MS |
MxGateway:Worker:WriteCompletionWaitMilliseconds |
1500 ms |
MXGATEWAY_EVENT_QUEUE_CAPACITY |
MxGateway:Worker:EventQueueCapacity |
10000 events |
MXGATEWAY_ALARM_POLL_INTERVAL_MS |
MxGateway:Alarms:PollIntervalMilliseconds |
500 ms |
MXGATEWAY_ALARM_MAX_ALARMS_PER_FETCH |
MxGateway:Alarms:MaxAlarmsPerFetch |
1024 alarms |
The write-completion wait applies to the four single-item write variants:
Write, Write2, WriteSecured, and WriteSecured2. Bulk writes report COM
acceptance per entry and do not wait for OnWriteComplete rows.
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 runs once. The default probe
only verifies that the worker did not exit immediately; a worker that has
already exited cannot be recovered by waiting, so the probe is not retried.
Real readiness is the pipe connection, hello, and WorkerReady handshake that
WorkerClient performs after the launch, under the same
WorkerOptions.StartupTimeoutSeconds budget. (The former
StartupProbeRetryAttempts / StartupProbeRetryDelayMilliseconds options were
removed because no shipped probe could ever produce a retryable failure; a
stale value in configuration is ignored by the binder.)
The worker uses the exported pipe-attempt value 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/ZB.MOM.WW.MxGateway.Tests/ZB.MOM.WW.MxGateway.Tests.csproj --filter WorkerProcessLauncherTests
Run the gateway build because the launcher is part of ZB.MOM.WW.MxGateway.Server:
dotnet build src/ZB.MOM.WW.MxGateway.Server/ZB.MOM.WW.MxGateway.Server.csproj