PHP runtime metrics (PHM)

The SkyWalking PHP agent can report PHP Health Metrics (PHM) through the native Meter protocol. OAP parses them with MAL rules in php-runtime.yaml and stores them as meter_* metrics on the General Service layer.

Requires a PHP agent build that includes PHM (merged in apache/skywalking-php 1.2.0+).

Platform support

PHM process meters are Linux only. In grpc / kafka reporter mode, the forked reporter worker samples the parent PHP process (getppid()) through /proc (/proc/{pid}/status, stat, and fd). They are not collected on macOS or Windows, and PHM does not run when reporter_type = standalone. Instance dashboard widgets stay hidden when no meter_instance_php_* data exists.

Data flow

PHM is On by default on Linux when the agent is active (skywalking_agent.enable = On). Set skywalking_agent.metrics_enable = Off to disable.
The forked reporter worker boots skywalking::metrics::Metricer in start_worker and samples /proc on metrics_report_period (default 30 seconds). No HTTP traffic is required.
OAP loads meter-analyzer-config/php-runtime.yaml when php-runtime is listed in agent-analyzer.default.meterAnalyzerActiveFiles.
Horizon UI renders widgets on General Service → Instance → Dashboard when the corresponding meter_instance_php_* metrics exist.

Agent setup

ini

; Default On on Linux when the agent is active.
; skywalking_agent.metrics_enable = Off

skywalking_agent.metrics_report_period = 30

Refer to the PHP agent README and INI settings documentation for details.

OAP setup

Ensure php-runtime is active (included by default when using the stock application.yml):

yaml

agent-analyzer:
  default:
    meterAnalyzerActiveFiles: ...,php-runtime,...

UI location

Layer: General Service (GENERAL)

Path: select a PHP service → Instance → Dashboard

Widgets appear only when PHM data is present (visibleWhen checks each meter_instance_php_* expression).

Runtime metrics

Agent meter names (reported by the PHP agent) are rewritten by OAP MAL metricPrefix: meter:

Unit	Agent meter name	OAP / UI metric name	Description	Data Source
%	instance_php_process_cpu_utilization	meter_instance_php_process_cpu_utilization	Process CPU utilization	SkyWalking PHP Agent
MB	instance_php_memory_used_mb	meter_instance_php_memory_used_mb	Resident memory (VmRSS from /proc)	SkyWalking PHP Agent
MB	instance_php_memory_peak_mb	meter_instance_php_memory_peak_mb	Peak resident memory (VmHWM from /proc)	SkyWalking PHP Agent
MB	instance_php_virtual_memory_mb	meter_instance_php_virtual_memory_mb	Virtual memory (VmSize from /proc)	SkyWalking PHP Agent
—	instance_php_thread_count	meter_instance_php_thread_count	OS thread count (Threads from /proc)	SkyWalking PHP Agent
—	instance_php_open_fd_count	meter_instance_php_open_fd_count	Open file descriptor count	SkyWalking PHP Agent

Customizations

You can customize MAL expressions or dashboard panels. Metric definitions and expression rules are in /meter-analyzer-config/php-runtime.yaml. Instance dashboard widget templates ship from the SkyWalking Horizon UI bundle (general.json in apache/skywalking-horizon-ui).