Process Detail

Shows all tasks of a specific process within a workflow run, with resource usage statistics and a task table. Navigate here by clicking a process name in the Process Table.

Process Directives

A card at the top shows the resource allocation for this process: CPU, Memory, and Container image. These reflect the Nextflow process directives from the workflow definition.

Box Plot Charts

Box plots (min, Q1, median, Q3, max) visualize the distribution of resource usage and timing across all tasks (latest attempt per task).

Resource Charts

Chart	Description
CPU %	Actual CPU utilization. Compare against allocated CPUs to spot over/under-provisioning.
Peak RSS	Peak memory used. Compare against allocated memory.
Read/Write I/O (physical)	read_bytes / write_bytes -- actual storage device I/O
Read/Write I/O (logical)	rchar / wchar -- total I/O as seen by the process

Physical vs Logical I/O

The process detail page shows two pairs of I/O charts because Linux tracks I/O at two levels:

• read_bytes / write_bytes (physical) -- Bytes actually read from or written to the storage device. This is the I/O that hits disk.
• rchar / wchar (logical) -- Total bytes the process requested to read or write, including data served from the operating system's page cache.

rchar/wchar will typically be higher than read_bytes/write_bytes because:

• Shared reference files (genomes, indexes) are often already in the page cache from other tasks on the same node. The process reads them (rchar increases), but no physical disk I/O occurs (read_bytes stays low).
• Buffered writes are counted in wchar when the process writes, but may not be flushed to disk until later.

In practice: use rchar/wchar to understand how much data a task processes, and read_bytes/write_bytes to understand actual storage load.

Timing Charts

Chart	Description
Queue Duration	Submission to execution start (waiting for a node)
Execution Duration	Task command wallclock time
Overhead Duration	File staging and unstaging time (total minus execution minus queue)
Total Duration	End-to-end time from submission to completion

Units auto-scale: bytes use binary units (B through TB), time uses seconds/minutes/hours based on the dataset.

Task Table

Lists all tasks for this process. Click any row to open the task detail page.

Columns

Column	Description
Status	Task status
Tag	Task tag, as defined in the workflow's process code. Links to a cross-process view of all tasks with the same tag.
Duration / Queue / Execution / Stage	Timing breakdown
Memory / CPU	Peak RSS and CPU utilization
rchar / wchar / read_bytes / write_bytes	I/O metrics
Attempts	Number of execution attempts

Filtering

• Status filter -- Show only tasks with a specific status
• Minimum attempts -- Show only retried tasks (at least N attempts)
• Text search -- Filter by task tag

Filtered Box Plots

All filters also update the box plot charts, so you can analyze resource usage for a specific subset of tasks (e.g., only failed tasks).

All columns are sortable -- useful for identifying outliers (e.g., sort by memory descending to find the highest consumers).