Interface BatchProcessOptions

Command to end the child batch process. If not provided (or undefined), stdin will be closed to signal to the child process that it may terminate, and if it does not shut down within endGracefulWaitTimeMillis, it will be SIGHUP'ed.

Expected text to print if a command fails. Cannot be blank. Strings will be interpreted as a regular expression fragment.

If provided, and healthCheckIntervalMillis is greater than 0, or the previous task failed, this command will be sent to child processes.

If the command outputs to stderr or returns a fail string, the process will be considered unhealthy and recycled. Lines discarded by shouldIgnoreStderrLine do not count as stderr output.

Recognize a worker's request to retire after its current task settles. Called synchronously for complete stdout/stderr lines, without LF or CRLF. Return true to consume the entire line (including its line ending): it will not reach the task parser, pass/fail matching, taskData, noTaskData, stderr logging, or shouldIgnoreStderrLine. Return false to retain normal handling. Use an exact, reserved control line rather than ordinary log text.

A match immediately prevents new tasks and health checks. The active task keeps receiving output and retains its normal timeout; the request itself neither resolves nor rejects it. Once idle, the worker is gracefully ended with reason retired. Repeated requests have no additional effect. Startup and idle workers can also request retirement. The worker should wait for the parent's exit command or stdin closure instead of exiting itself.

For ordering, write the marker and then the task completion token through the same stdout writer. Both must end with a newline. The marker is consumed before completion is processed, even when both arrive in one chunk. Stderr requests have no ordering guarantee relative to stdout completion.

Enabling this option buffers stdout and stderr into lines, independently of chunk boundaries. Stdout completion tokens must therefore end with a newline. Partial lines block new assignments; received fragments are flushed before task parsing or at EOF. Fragments without a pending owning task are also flushed after no more data arrives for streamFlushMillis, retaining normal stray-output handling. Idle retirement markers must finish within that interval. Fragments are never reassembled across a flush boundary. Unterminated fragments are ordinary output, never retirement requests. Lines longer than 64 * 1024 UTF-16 code units bypass recognition. If the callback throws, the worker is ended with stdout.error or stderr.error and its active task is rejected.

Defaults to undefined, preserving existing stream handling.

Expected text to print if a command passes. Cannot be blank. Strings will be interpreted as a regular expression fragment.

Called for each complete line written to stderr. Return true to discard that line before it is logged, associated with a task, or treated as taskless process output. The line ending is not included.

Lines are assembled independently of stream chunk boundaries. An unterminated fragment is evaluated before its task is parsed, when no more stderr arrives for streamFlushMillis, or when the stream ends. With isRetirementRequest enabled, the quiet-period flush waits until the line's owning task is no longer pending. The worker is not assigned another task while a fragment is pending.

Lines longer than 64 KiB bypass this callback and retain the normal stderr behavior. If this callback throws, its line is retained and the worker is ended with a stderr.error.

Use this only for exact, known advisory lines. Every line for which this returns false retains the normal, potentially fatal stderr behavior. Defaults to undefined, which preserves the existing immediate handling of every stderr chunk without line buffering.

Low-overhead command to verify the child batch process has started correctly. This "startup command" is invoked immediately after spawn, and must complete successfully before any user tasks are assigned to the process.

Typically this runs a version check (like -ver for ExifTool), hence the name. The command should be fast and reliable.

If this command fails or times out (per BatchClusterOptions.spawnTimeoutMillis), the process is considered broken and will be terminated.