MCLOUD-6023: Investigate Redis scan keys eviction

[shiftedreality]

Description

Per Redis (https://docs.redislabs.com/latest/ri/memory-optimizations/reclaim-expired-keys-memory-faster)

You can set up a cron job that runs the scan command after an interval which helps in reclaiming the memory of the expired keys.

A cron job should be created that will use the SCAN command with a COUNT parameter (value 10,000) that will run every 12 hours. Details can be found in the following links:

• https://serverfault.com/questions/724047/avoiding-swap-on-elasticache-redis
• https://docs.redislabs.com/latest/ri/memory-optimizations/reclaim-expired-keys-memory-faster/
• https://tech.trivago.com/2017/01/25/learn-redis-the-hard-way-in-production/
• https://blog.twitter.com/engineering/en_us/topics/infrastructure/2019/improving-key-expiration-in-redis.html
• https://natmeurer.com/redis-setting-up-a-regularly-updated-cache-using-azure/

Fixed Issues (if relevant)

1. https://jira.corp.magento.com/browse/MCLOUD-6023

Manual testing scenarios

1. Run ./bin/magento cache:evict from CLI
2. Observe the non-zero number of evicted keys
3. Remove logs rm -rf var/log/*
4. Enable cron process by setting 'cache_evict' => ['enabled' => 1], in app/etc/env.php
5. Run cron manually bin/magento cron:run
6. Run cat var/log/system.log | grep "Keys scanned: " and see log entries

Release notes

Added command ./bin/magento cache:evict to force run Redis Sync and evict expired keys

Associated documentation updates

Add link to Magento DevDocs PR or Issue, if needed.

Contribution checklist

• Pull request has a meaningful description of its purpose
• Pull request introduces user-facing changes and includes meaningful updates for any required release notes and documentation changes
• All commits are accompanied by meaningful commit messages

[oshmyheliuk]

Looks like you should check if $cacheConfig is an array and contains required keys?

[shiftedreality]

Added

[andriyShevtsov]

QA approved