Docs » Available host and application monitors » Configure application receivers for caches and memory » OPcache

OPcache 🔗

Description 🔗

The Splunk Distribution of OpenTelemetry Collector provides this integration as the collectd/opcache monitor type for the Smart Agent Receiver.

Use this monitor to retrieve metrics from OPcache using the opcache_get_status() function, which improves PHP performance by storing precompiled script bytecode in shared memory.


This monitor is not available on Windows as collectd plugins are only supported in Linux and Kubernetes.

Benefits 🔗

After you configure the integration, you can access these features:

  • View metrics. You can create your own custom dashboards, and most monitors provide built-in dashboards as well. For information about dashboards, see View dashboards in Observability Cloud.

  • View a data-driven visualization of the physical servers, virtual machines, AWS instances, and other resources in your environment that are visible to Infrastructure Monitoring. For information about navigators, see Splunk Infrastructure Monitoring navigators.

  • Access the Metric Finder and search for metrics sent by the monitor. For information, see Use the Metric Finder.

PHP setup 🔗

Install the following PHP script on your PHP web server:

header('Content-Type: application/json');
echo json_encode($status,JSON_PRETTY_PRINT);

The following is an example using NGINX:

location ~ /monitoring/.*\.php$ {
    #access_log off;
    allow ::1;
    deny all;
    include fastcgi_params;
    fastcgi_split_path_info ^(.+\.php)(/.*)$;
    fastcgi_param  PHP_ADMIN_VALUE "open_basedir=/var/log:/usr/bin:/srv/http/monitoring";
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_pass php-handler;

Put the opcache_stat.php script in /srv/http/monitoring and run the following command:

curl http://localhost/monitoring/opcache_stat.php
"opcache_enabled": true,
"cache_full": false,
"restart_pending": false,
"restart_in_progress": false,
"memory_usage": {
    "used_memory": 82614848,
    "free_memory": 183437232,
    "wasted_memory": 2383376,
    "current_wasted_percentage": 0.88787674903869629

Installation 🔗

Follow these steps to deploy this integration:

  1. Deploy the Splunk Distribution of OpenTelemetry Collector to your host or container platform:

  2. Configure the monitor, as described in the Configuration section.

  3. Restart the Splunk Distribution of OpenTelemetry Collector.

Configuration 🔗

To use this Smart Agent monitor with the Collector, include the smartagent receiver and service pipeline in your configuration file. The Smart Agent receiver is fully supported only on x86_64/amd64 platforms.

See the examples below for more details.


Provide an OPcache monitor entry in your Collector or Smart Agent (deprecated) configuration. Use the appropriate form for your agent type.

Splunk Distribution of OpenTelemetry Collector 🔗

To activate this monitor in the Splunk Distribution of OpenTelemetry Collector, add the following to your agent configuration:

    type: collectd/opcache
    ...  # Additional config

To complete the monitor activation, you must also include the smartagent/opcache receiver item in a metrics pipeline. To do this, add the receiver item to the service > pipelines > metrics > receivers section of your configuration file. For example:

      receivers: [smartagent/opcache]

Smart Agent 🔗

To activate this monitor in the Smart Agent, add the following to your agent configuration:

monitors:  # All monitor config goes under this key
 - type: collectd/opcache
   ...  # Additional config

See Install and configure the SignalFx Smart Agent for an autogenerated example of a YAML configuration file, with default values where applicable.

Configuration examples 🔗

If the status script results in an endpoint other than /opcache_stat.php, use the path configuration option as in the following example:

 - type: collectd/opcache
   host: localhost
   port: 80
   path: "/opcache"

You can also define the full URL using the url configuration option, as shown in the following example:

 - type: collectd/opcache
   host: localhost
   port: 80
   useHTTPS: true
   url: "http://{{.host}}:{{.port}}/opcache"
   # useHTTPS is ignored.

Configuration settings 🔗

The following table shows the configuration options for this monitor:








Host name of the web server. For example,




Port number of the web server. For example, 80. The default value is 0.




If true, the monitor uses an HTTPS connection. The default value is false.




Path of the scrape URL for the OPcache script. The default value is /opcache_stat.php.




Either a final URL or a Go template populated with the host, port, and path values.




Name of the monitor. Sent as the plugin_instance dimension.

Metrics 🔗

Get help 🔗

If you are not able to see your data in Splunk Observability Cloud, try these tips:

To learn about even more support options, see Splunk Customer Success.