Cache Manager¶

The Cache Manager is a cronjob which regularly updates persistent cache entries and purges stale cache entries when the cache size exceeds configured limits. It optimises performance by pre-calculating expensive operations and intelligently managing cache eviction.

Configuration Example¶

cache_manager:
  schedule: '*/10 * * * *'             # every 10 minutes
  successful_jobs_history_limit: 1
  failed_jobs_history_limit: 1
  max_cache_size_bytes: 1000000000   # 1 GB
  min_pruning_bytes: 100000000       # 100 MB
  cache_pruning_weights:
    creation_date_weight: 0
    last_update_weight: 0
    delete_after_weight: -1.5        # stale entries -> delete
    keep_until_weight: -1            # expired entries -> delete
    last_read_weight: -1             # unused entries -> delete
    read_count_weight: 10            # frequently read -> keep
    revision_weight: 0
    costs_weight: 10                 # expensive to recalculate -> keep
    size_weight: 0
  prefill_function_caches:
    functions:
      - compliance-summary
      - component-versions
    components:
      - component_name: ocm.software/open-delivery-gear
        version: greatest
      - component_name: acme.org/my-component
        version: 1.0.0

Top-Level Options¶

Option	Type	Default	Description
`schedule`	string	`/10 * * *`	Cron schedule for running the cronjob (every 10 minutes by default).
`successful_jobs_history_limit`	int	`1`	Number of successful job executions to retain in history.
`failed_jobs_history_limit`	int	`1`	Number of failed job executions to retain in history.
`max_cache_size_bytes`	int	`1000000000`	Maximum allowed cache size in bytes (1 GB default).
`min_pruning_bytes`	int	`100000000`	Amount of space to free when pruning (100 MB default).
`cache_pruning_weights`	object	—	Weights for cache eviction algorithm. See weights below.
`prefill_function_caches`	object	—	Configuration for pre-calculating function results.

Cache Pruning Weights¶

Each weight influences the cache eviction algorithm. Higher weights make entries less likely to be deleted:

Weight	Type	Default	Description
`creation_date_weight`	float	`0`	Weight based on when entry was created.
`last_update_weight`	float	`0`	Weight based on last update time.
`delete_after_weight`	float	`-1.5`	Negative value prioritizes deletion of stale entries.
`keep_until_weight`	float	`-1`	Negative value prioritizes deletion of expired entries.
`last_read_weight`	float	`-1`	Negative value prioritizes deletion of long-unused entries.
`read_count_weight`	float	`10`	Positive value protects frequently accessed entries.
`revision_weight`	float	`0`	Weight based on entry revision.
`costs_weight`	float	`10`	Positive value protects expensive-to-recalculate entries.
`size_weight`	float	`0`	Weight based on entry size.

Prefill Configuration¶

The prefill_function_caches object contains:

Option	Type	Description
`functions`	list	Functions to pre-calculate. Options: `compliance-summary`, `component-versions`.
`components`	list	Components for which to pre-calculate results.

Each component in the components list has:

Option	Type	Required	Description
`component_name`	string	yes	OCM component name.
`version`	string or object	yes	Version (`greatest` for latest, specific version, or GitHub source).

Configuration Details¶

`prefill_function_caches`¶

Pre-calculates expensive operations for specified components to improve dashboard and API response times.

Available Functions¶

compliance-summary
Pre-calculates compliance summaries, aggregating findings across components. This speeds up dashboard landing pages and compliance reports.

component-versions
Pre-calculates component version lists and metadata. This accelerates component browsing and navigation.

Prefill Components¶

Specify which components should have results pre-calculated:

prefill_function_caches:
  functions:
    - compliance-summary
    - component-versions
  components:
    - component_name: ocm.software/open-delivery-gear
      version: greatest              # Always prefill latest version
    - component_name: acme.org/critical-component
      version: 2.1.0                 # Prefill specific version

Recommendation: Only prefill components that are:

Frequently accessed in the dashboard
Large enough that calculation is noticeably slow
Part of critical workflows (compliance reporting, executive dashboards)

Prefilling too many components can increase cache manager runtime and cache size without meaningful performance benefits.

Monitoring Cache Health¶

Watch for these indicators that cache tuning is needed:

Frequent pruning events: Increase max_cache_size_bytes
Slow dashboard loading: Add components to prefill_function_caches
High cache manager runtime: Reduce prefill components or increase min_pruning_bytes
Stale cached data: Ensure delete_after_weight and keep_until_weight are negative