Logging Improvements

We’ve added new metrics for feature developers on PB Engine that help to expose underlying performance drivers. These metrics will be used by Arc to help diagnose performance and stability related issues.

Cache- Enabling logging for request information from fusion-engine to the Arc managed cache proxy content fetched in a webpage rendering.

• Status written as success, stale, or miss
• Latency in ms
• Size in bytes
• Content source name

Cache metrics will appear in logs for requests with either:

• Fetch latency greater than an Arc-managed threshold (ex: 250ms)
• Response size great greater than an Arc-managed threshold (ex: 1mb)

Content - Enabling logging for request information from fusion-engine to customer specified content sources.

• Status written as success, stale, or miss
• Latency in ms
• Size in bytes
• Content source name

Content fetch metrics will appear in logs for requests with either:

• Fetch latency greater than an Arc-managed threshold (ex: 2500ms)
• Response size great greater than an Arc-managed threshold (ex: 1mb)

Database - Enabling logging for database requests from fusion-engine to the database that stores pages and templates.

• Latency in ms

Database fetch metrics will appear in the logs for requests with:

• Fetch latency greater than an Arc-managed threshold (ex: 500ms)

Render - Enabling logging of the time it takes for an individual component to render during the webpage request flow.

• Latency in ms
• Component name

Component rendering metrics will appear in the logs for requests with:

• Render latency greater than an Arc-managed threshold (ex: 100ms)

In local environments, developers are also free to modify their own metrics logging for thresholds, using two environment variables:

• OVERRIDE_THRESHOLDS - JSON object containing name/value pairs to describe the minimum value for a metric to be logged.
• LOG_METRICS - Flag for allowing or suppressing all metrics logging.

Note

Environment variables are defined in file .env for the local environment, and in the /environment/ directory for other environments.

LOG_METRICS

Defaults to true. Changing this to false will prevent all logging of metrics. Example: LOG_METRICS=false

OVERRIDE_THRESHOLDS

Defaults to empty. Changing this to add override thresholds will cause the subject metric to be logged only when its value equals or exceeds the given threshold. Example: OVERRIDE_THRESHOLDS={ “render.latency”: 500, “db.latency”: 20 }

Omit the prefix “arc.fusion.” when specifying the metric name.

Available metrics:

• cache.latency
• cache.bytes
• compile.latency
• content.latency
• db.latency
• render.latency