trace

The trace scope controls the generation of the trace file.

trace.directory

Added in version 26.10

The directory where the trace file should be saved. The path is resolved against the workflow output directory (outputDir). It must be a relative path within the output directory, and it cannot be used when trace.file is an absolute path. By default, it is not used and trace.file is resolved against the launch directory.

trace.enabled

Create the trace file on workflow completion (default: false).

trace.fields

Comma-separated list of fields to include in the trace file.

Available fields:

task_id

Task ID.

hash

Task hash code.

native_id

Task ID given by the underlying execution system e.g. POSIX process PID when executed locally, job ID when executed by a grid engine, etc.

process

Nextflow process name.

tag

User provided identifier associated with this task.

name

Task name.

status

Task status. OptionsNEW, SUBMITTED, RUNNING, COMPLETED, FAILED, and ABORTED.

exit

POSIX process exit status.

module

Environment module used to run the task.

container

Docker image name used to execute the task.

cpus

The CPUs number request for the task execution.

time

The time request for the task execution

disk

The disk space request for the task execution.

memory

The memory request for the task execution.

attempt

Attempt at which the task completed.

submit

Timestamp when the task has been submitted.

start

Timestamp when the task execution has started.

complete

Timestamp when task execution has completed.

duration

Time elapsed to complete since the submission.

realtime

Task execution time i.e. delta between completion and start timestamp.

queue

The queue that the executor attempted to run the process on.

%cpu

Percentage of CPU used by the process.

%mem

Percentage of memory used by the process.

rss

Real memory (resident set) size of the process. Equivalent to ps -o rss .

vmem

Virtual memory size of the process. Equivalent to ps -o vsize .

peak_rss

Peak of real memory. Data is read from field VmHWM in /proc/$pid/status file.

peak_vmem

Peak of virtual memory. Data is read from field VmPeak in /proc/$pid/status file.

rchar

Number of bytes the process read, using any read-like system call from files, pipes, tty, etc. Data is read from /proc/$pid/io.

wchar

Number of bytes the process wrote, using any write-like system call. Data is read from /proc/$pid/io.

syscr

Number of read-like system call invocations that the process performed. Data is read from /proc/$pid/io.

syscw

Number of write-like system call invocations that the process performed. Data is read from /proc/$pid/io.

read_bytes

Number of bytes the process directly read from disk. Data is read from /proc/$pid/io.

write_bytes

Number of bytes the process originally dirtied in the page-cache (assuming they will go to disk later). Data is read from /proc/$pid/io.

vol_ctxt

Number of voluntary context switches. Data is read from field voluntary_ctxt_switches in /proc/$pid/status file.

inv_ctxt

Number of involuntary context switches. Data is read from field nonvoluntary_ctxt_switches in /proc/$pid/status file.

env

The variables defined in task execution environment.

workdir

The directory path where the task was executed.

script

The task command script.

scratch

The value of the process scratch directive.

error_action

The action applied on error for task failure.

hostname

The host on which the task was executed. Supported only for the Kubernetes executor yet. Activate with k8s.fetchNodeName = true in the Nextflow config file.

cpu_model

The name of the CPU model used to execute the task. This data is read from/proc/cpuinfo.

trace.file

Trace file name (default: 'trace-<timestamp>.txt').

trace.overwrite

Overwrite any existing trace file with the same name (default: false).

trace.raw

Report trace metrics as raw numbers where applicable, i.e. report duration values in milliseconds and memory values in bytes (default: false).

trace.sep

Character used to separate values in each row (default: \t).