Apache Sling Journal based Content Distribution - Core

This module is part of the Apache Sling project, it implements Apache Sling Content Distribution agents on a message journal. Please refer to the documentation to learn about the use case and general design.

Metrics

This bundle exposes comprehensive metrics for monitoring publisher and subscriber operations. All metrics are exposed through the Apache Sling Metrics Service. Metric names use underscores instead of dots and are prefixed with sling_.

Publisher Metrics

Publisher metrics (prefixed with sling_distribution_journal_publisher_) track package export, request handling, package building, queue operations, and subscriber discovery:

• Package Export: sling_distribution_journal_publisher_exported_package_size (histogram)
• Request Handling: sling_distribution_journal_publisher_accepted_requests, sling_distribution_journal_publisher_dropped_requests (meters)
• Package Building: sling_distribution_journal_publisher_build_package_duration, sling_distribution_journal_publisher_enqueue_package_duration (timers)
• Queue Operations: sling_distribution_journal_publisher_queue_size (gauge, tagged pub_name and clearable), sling_distribution_journal_publisher_queue_cache_fetch_count, sling_distribution_journal_publisher_queue_access_error_count (counters)
• Subscriber Discovery: sling_distribution_journal_publisher_subscriber_count (gauge)

Subscriber Metrics

Subscriber metrics (prefixed with sling_distribution_journal_subscriber_) track package import, processing, errors, and distribution duration:

• Package Import: sling_distribution_journal_subscriber_imported_package_size, sling_distribution_journal_subscriber_imported_package_duration, sling_distribution_journal_subscriber_current_import_duration (histogram/timer/gauge)
• Package Status: sling_distribution_journal_subscriber_package_status_count (counter) with status tags (IMPORTED, REMOVED, REMOVED_FAILED)
• Error Tracking: sling_distribution_journal_subscriber_transient_import_errors, sling_distribution_journal_subscriber_permanent_import_errors, sling_distribution_journal_subscriber_import_errors, sling_distribution_journal_subscriber_current_retries (counters/gauge)
• Processing: Pre/post-processing and installation metrics (counters/timers)
• Distribution Duration: sling_distribution_journal_subscriber_request_distributed_duration, sling_distribution_journal_subscriber_package_journal_distribution_duration (timers)
• Readiness: sling_distribution_journal_subscriber_readiness_duration (timer) with ready reason tags
• FileVault: sling_distribution_journal_subscriber_fv_message_count, sling_distribution_journal_subscriber_fv_error_count (counters)

All metrics are tagged with sub_name/pub_name and editable (for subscriber metrics) to enable filtering and aggregation.

For a complete list of all metrics with detailed descriptions, see the Metrics Overview.