Server Metrics Reference

The agent collects the following metrics every 15 seconds (configurable).

CPU

Metric	Unit	Description
`cpu.usage_percent`	%	Total CPU utilisation (all cores averaged)
`cpu.user_percent`	%	User-space CPU time
`cpu.system_percent`	%	Kernel CPU time
`cpu.iowait_percent`	%	Time waiting on I/O
`cpu.steal_percent`	%	CPU stolen by hypervisor (VMs)
`cpu.load_1`	—	1-minute load average
`cpu.load_5`	—	5-minute load average
`cpu.load_15`	—	15-minute load average

Default alert thresholds:

cpu.usage_percent > 85% for 5 minutes → Warning
cpu.usage_percent > 95% for 2 minutes → Critical

Memory

Metric	Unit	Description
`mem.total_bytes`	bytes	Total physical RAM
`mem.used_bytes`	bytes	Used RAM (excluding buffers/cache)
`mem.free_bytes`	bytes	Free RAM
`mem.used_percent`	%	Used / Total
`mem.buffers_bytes`	bytes	Kernel buffers
`mem.cached_bytes`	bytes	Disk page cache
`swap.total_bytes`	bytes	Total swap
`swap.used_bytes`	bytes	Used swap
`swap.used_percent`	%	Swap usage

Disk

Metric	Unit	Description
`disk.{mount}.total_bytes`	bytes	Total capacity for each mount point
`disk.{mount}.used_bytes`	bytes	Used space
`disk.{mount}.free_bytes`	bytes	Available space
`disk.{mount}.used_percent`	%	Used / Total
`disk.{mount}.inode_used_percent`	%	Inode usage (critical for mail servers)

Default alert thresholds:

disk./.used_percent > 85% → Warning
disk./.used_percent > 95% → Critical

Network

Metric	Unit	Description
`net.{iface}.bytes_recv_rate`	bytes/s	Inbound throughput
`net.{iface}.bytes_sent_rate`	bytes/s	Outbound throughput
`net.{iface}.packets_recv_rate`	pkt/s	Inbound packet rate
`net.{iface}.packets_sent_rate`	pkt/s	Outbound packet rate
`net.{iface}.err_in_rate`	errors/s	Inbound errors
`net.{iface}.err_out_rate`	errors/s	Outbound errors
`net.{iface}.drop_in_rate`	drops/s	Dropped inbound packets

Processes

The top-20 processes by CPU and memory are reported every 60 seconds:

{
  "pid": 1234,
  "name": "php-fpm",
  "cpu_percent": 12.4,
  "mem_rss_bytes": 134217728,
  "status": "running",
  "user": "www-data",
  "cmdline": "php-fpm: worker process"
}

System info (reported once on connect)

OS name, version, kernel
CPU model, core count
Total RAM
Hostname
Public IP
Uptime

Overview Uptime & HTTP Checks