freeze
Input Stack:
|
⇨ | Output Stack: |
Remove all items from the main stack and move them to a separate frozen stack that
cannot be modified except by additional :freeze operations. At the end of execution,
the final result includes both the frozen contents and any items remaining on the main stack.
This operation is essential for protecting certain expressions from being modified by stack manipulation operations, particularly useful when building dashboard templates for overlay expressions.
Parameters¶
- ...: All items currently on the main stack (variable number of arguments)
Key Behavior¶
- Isolation: Frozen items are protected from further stack manipulation
- Preservation: Frozen items maintain their original order
- Accumulation: Multiple
:freezeoperations add to the frozen stack - Final output: Frozen items appear in the final result alongside main stack items
Primary Use Case: Overlays on Dashboards¶
The most common use case is protecting overlay expressions for graphs on a dashboard. Consider an overlay showing network errors that should appear on all graphs in a dashboard, regardless of filtering:
Problem: Dashboard filtering affects all expressions:
# This filtering would break the overlay
,:list,(,nf.cluster,{{ selected_cluster }},:eq,:cq,),:each
Solution: Freeze the overlay to protect it:
# Protected overlay expression - won't be affected by filtering
name,networkErrors,:eq,:sum,50,:gt,:vspan,40,:alpha,
:freeze,
# Main dashboard content - will be filtered
name,ssCpuUser,:eq,:avg,1,:axis,
name,loadavg1,:eq,:avg,2,:axis,
# Dashboard filtering - only applies to main stack
:list,(,nf.cluster,{{ selected_cluster }},:eq,:cq,),:each
Since: 1.6
Examples¶
Basic freeze operation:
a,b,c,:freeze
| Pos | Input | Output |
|---|---|---|
| 0 | c | c |
| 1 | b | b |
| 2 | a | a |
This moves a, b, and c from the main stack to the frozen stack, where they
cannot be modified by subsequent operations.