What Are func: Metrics?
Extension metrics — including calculated func: metrics
Calculated metrics let you compute values server-side without writing code. Prefix the key with func::
- key: func:my_ext.uptime_hours
value: metric:my_ext.uptime_ticks
operand: 100
operator: DIVIDE
type: gauge
Available Operators
Operator What It Does Example
───────── ────────────────────────── ──────────────────────────
DIVIDE metric / operand Ticks → hours (÷ 360000)
MULTIPLY metric × operand Bytes → bits (× 8)
ADD metric + operand Offset correction
SUBTRACT metric - operand Baseline subtraction
REMAINDER metric % operand Modulo
Common Patterns
# Convert SNMP ticks (1/100 sec) to hours
- key: func:my_ext.uptime_hours
value: metric:my_ext.uptime_ticks
operand: 360000
operator: DIVIDE
type: gauge
# Convert bytes to megabytes
- key: func:my_ext.memory_mb
value: metric:my_ext.memory_bytes
operand: 1048576
operator: DIVIDE
type: gauge
# Percentage from two counters
- key: func:my_ext.error_rate
value: metric:my_ext.errors.count
operand: metric:my_ext.total.count
operator: DIVIDE
type: gauge
⚠️ func: metrics are NOT stored in Grail — they only work in entity screens and classic dashboards. For Gen3 DQL dashboards, do the math in DQL instead.
💡 Use func: metrics for unit conversions (ticks→hours, bytes→MB) and simple ratios. For complex calculations, use Python extensions instead.
🛠 Try it: Open Ctrl+K → "Metrics" → search for "func:" to find calculated metrics from extensions. These are computed at query time from raw metrics — they don't cost extra storage but give you derived insights like utilization percentages.