Nuxeo provides a Redis integration via the
Redis is not a hard requirement for running the Nuxeo Platform; it is used as a backend to provide alternate implementation of some services inside the platform. However, we do provide these implementations because we think they can be useful.
Nuxeo Core Cache provides a service to declare and use caches. This cache system is used for:
- Nuxeo Directories (caching directories entries)
- UserManager (caching principals)
- Nuxeo Drive (caching synchronization roots)
It can also be used in your custom code.
The Cache has a default "in memory" implementation, but
nuxeo-core-redis provides another implementation that allows to:
- Have an out of JVM memory cache storage. It opens the way to have big caches without hurting the JVM.
- Share the same cache between several Nuxeo nodes. In cluster mode this can increase cache efficiency.
- Manage cluster wide invalidations. Updating the user on one node will impact the central cache: all nodes see the exact same data.
You can configure the backend storage on a per cache basis: Directory A could use Redis while directory B could use in memory.
The WorkManager handles asynchronous jobs:
- Schedule Jobs and store them in queues
- Assign execution slots to queues
- Execute the jobs
In the default implementation, job queues are in the JVM memory. But this model has some limitations:
- Stacking a lot of jobs will consume JVM Memory
- In cluster mode each Nuxeo node maintains its own queue
- When a Nuxeo server is restarted, all the queued jobs are lost
nuxeo-core-redis provides an alternate implementation of the queuing system based on Redis:
- Jobs are then stored outside of JVM memory. That's why Work have to be serializable: they are serialized and stored in Redis.
- Jobs can be shared across cluster nodes. This allows to dedicate some nodes to some specific processing.
- Jobs survive a Nuxeo restart. When Redis persistence is activated, the jobs even survive a Redis restart.
By default Lock managed on documents are stored in the repository backend. When the locking system is heavily used, it can create a lot of very small transactions against the database backend.
nuxeo-core-redis provides a Redis-based implementation of the locking system that is resilient as the database implementation, but easier to scale.
Visual Content Store (VCS) Row Cache Invalidation
Managing VCS (Meaning RDBMS) row cache invalidations with Redis instead of using the database can improve performance on concurrent writes and provides synchronous invalidations.
Document Based Storage (DBS) Cache Invalidation
For Nuxeo 8.10 and 9.10 the DBS layer (used to connect with MongoDB or Marklogic) has a cache its invalidation in cluster mode requires Redis.
RedisTransientStore is a Redis-based implementation of the Transient Store.
It becomes the default Transient Store if Redis is enabled.
It allows the parameters associated to the stored blobs to be shared across cluster nodes.
The following code can be used with the Redis client to delete old workers marked as running:
local keys = redis.call('KEYS', 'nuxeo:work:run:*') for _,k in ipairs(keys) do redis.call('DEL', k) end
Copy this code to a file named
delete_running_works.lua, change the Redis prefix if required (the default prefix value is
nuxeo) run the following command line:
redis-cli --eval /path/to/delete_running_works.lua
It finds all keys prefixed with
nuxeo:work:run then delete these keys.