Redis
This module integrates Drupal with Redis, a fast key-value store, to improve performance by providing backends for caching, locking, session handling, queuing, and more. It supports multiple Redis PHP implementations and offers cache performance reporting.
Integration of Drupal with the Redis key-value store as well as compatible alternatives/forks such as Valkey. It provides cache, lock, flood and queue backends and a cache performance report.
See documentation for more information and installation and configuration instructions as well as installation instructions for the backends mentioned below.
Provided backends
PhpRedis
The PhpRedis PHP extension.
Predis
The Predis PHP implementation, does not require an extension.
Relay
An alternative, proprietary PHP extension (https://relay.so/) that offers advanced features such as built-in clientside caching similar to ChainedFast cache backends.
Failover, sharding and partioning
Note: This information may be outdated and hasn't been reviewed for the current 8.x-1.x version.
There are numerous support and feature request issues about client sharding, failover ability, multi-server connection, ability to read from slave and server clustering opened in the issue queue. Note that there is no one universally efficient solution for this: most of the solutions require that you cannot use the MULTI/EXEC command using more than one key, and that you cannot use complex UNION and intersection features anymore.
Until this module grows with (a) mature and stable solution(s) we recommend that you read the official Redis documentation page about partionning.
The best solution for clustering and sharding today seems to be the proxy assisted partionning using tools such as Twemproxy.
Proxy-assisted sharding is the recommended way of sharding cache with the this module. If you intend to do so please use the Redis 3.x branch of this module.
Additional information
You can tune Redis for cache handling, see http://redis.io/topics/config.
External resources
- Pantheon wrote a nice article about Drupal using Redis and why they use it.
- Platform.sh also provides a tutorial to use Redis on the platform.sh hosting platform: Drupal 7, Drupal 8
- ASYNC Drupal made an installation tutorial video.
Credits
Development
Makina Corpus maintained the Drupal 7 version.
MD Systems maintains the Drupal 8 version.
Community
Great thanks to Irakli that granted me the commit access over this project.
Thanks to msonnabaum for the interest he shows for this modules and his numerous patches, and for his reactivity in finding critical bugs.
Thanks to David Strauss for patches.
Thanks to jtsnow for the smart design suggestions and patches.
Thanks to das-peter for a very peculiar bug fix, I would never have found this one.
Thanks to Berdir and Dave Reid for finding out that core tests were failing with this module.
Thanks to caiosba and Island Usurper for working out of the excessive cache clear problems.
Thanks to greggles for pushing this module to stable, and for the documentation fixes.
Thanks to omega8cc for her detailed important bug reports.
Thanks to SocialNicheGuru for testing the 3.x branch and giving me a lot of feedback.
The greatest thanks of all time to mja along with omega8cc for solving the deadlock problem. The later for working literally hours to find the source, the former for fixing it.
Thanks to mdupont for heavily testing the 3.x branch and providing resourceful feedback and patches for it.
Thanks to Berdir who is now the official 8.x branch maintainer.
Many thanks to axel.rutz which implemented the compressed cache backend, and to memtkmcc for testing it.
Over the life of this module, this list can grow very long. Want to be quoted here? Open an issue!