Class: ScheduleWorkers::AvailableTimesCacheCleaner

Inherits:
ApplicationWorker show all
Includes:
ElasticAPM::SpanHelpers
Defined in:
app/workers/schedule_workers/available_times_cache_cleaner.rb

Overview

ScheduleWorkers::AvailableTimesCacheCleaner This worker is responsible for cleaning up stale available_times cache keys on a scheduled basis. It addresses the memory bloat issue where multiple cache keys accumulate for the same restaurant package or restaurant add-on due to changes in agenda_setting, start_date, end_date, or time_zone.

Problem:

The cache key format includes a hash of variables like [agenda_setting, start_date, end_date].
When these values change, a new cache key is created, but old keys are not deleted.
This leads to Redis memory bloat with multiple stale keys per restaurant package/add-on.

Example of stale keys (for restaurant_package_37267):

available_times_v2_version_v2025-03-08:{restaurant_package_37267}:variables_331924283
available_times_v2_version_v2025-03-08:{restaurant_package_37267}:variables_3977971064
available_times_v2_version_v2025-03-08:{restaurant_package_37267}:variables_2558844315
... (23 keys consuming ~8MB for ONE package)

Solution:

- Keep only ONE key per restaurant_package or restaurant_add_on (the most recently accessed one)
- Delete all other stale keys

Author:

  • GitHub Copilot

Constant Summary collapse

REDIS_SCAN_COUNT =

Configuration

1000
BATCH_SIZE = 
100
CACHE_PATTERNS =

Cache key patterns to clean

[
  { pattern: 'available_times_v2_version_*:{restaurant_package_*}:*', id_regex: /:?\{restaurant_package_(\d+)\}:/,
    type: 'restaurant_package' },
  { pattern: 'restaurant-add-on-inv:{restaurant_add_on_*}:*', id_regex: /:?\{restaurant_add_on_(\d+)\}:/,
    type: 'restaurant_add_on' },
].freeze

Instance Method Summary collapse

Methods inherited from ApplicationWorker

unlimited_retry

Instance Method Details

#perform ⇒ Object

Main entry point for the worker



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# File 'app/workers/schedule_workers/available_times_cache_cleaner.rb', line 41

def perform
  ElasticAPM.with_span('Available Times Cache Cleanup', 'cache', subtype: 'redis', action: 'cleanup') do |_span|
    cleanup_stats = {
      restaurant_packages_processed: 0,
      restaurant_add_ons_processed: 0,
      stale_keys_deleted: 0,
      total_memory_freed: 0,
      errors: 0,
    }

    begin
      HH_LOGGER.info('available_times_cache_cleanup_started', {
                       timestamp: Time.current.iso8601,
                     })

      CACHE_PATTERNS.each do |config|
        # Scan and group keys by entity ID
        entity_keys = scan_and_group_keys(config[:pattern], config[:id_regex])

        HH_LOGGER.info('available_times_cache_scan_completed', {
                         type: config[:type],
                         unique_entities: entity_keys.size,
                         total_keys_found: entity_keys.values.flatten.size,
                       })

        # Process each entity
        entity_keys.each do |entity_id, keys|
          entity_stats = cleanup_entity_cache(entity_id, keys, config[:type])

          if config[:type] == 'restaurant_package'
            cleanup_stats[:restaurant_packages_processed] += 1
          else
            cleanup_stats[:restaurant_add_ons_processed] += 1
          end
          cleanup_stats[:stale_keys_deleted] += entity_stats[:deleted_count]
          cleanup_stats[:total_memory_freed] += entity_stats[:memory_freed]
        rescue StandardError => e
          cleanup_stats[:errors] += 1
          APMErrorHandler.report(e, context: { entity_id: entity_id, type: config[:type] })
        end
      end

      HH_LOGGER.info('available_times_cache_cleanup_completed', cleanup_stats.merge(
                                                                  memory_freed_mb: (cleanup_stats[:total_memory_freed] / 1024.0 / 1024.0).round(2),
                                                                ))
    rescue StandardError => e
      APMErrorHandler.report(e, context: { cleanup_stats: cleanup_stats })
      raise
    end
  end
end