Merge branch '2.3' into 2.4

Documentation/Filters/Cache.md

@@ -888,52 +888,6 @@ the cached data.
 storage=storage_inmemory
 ```
 
-### `storage_rocksdb`
-
-This storage module is not built by default and is not included in the
-MariaDB MaxScale packages.
-
-This storage module uses RocksDB database for storing the cached data. The
-directory where the RocksDB database will be created is by default created
-into the _MaxScale cache_ directory, which usually is not on a RAM disk. For
-maximum performance, you may want to explicitly place the RocksDB database
-on a RAM disk.
-```
-storage=storage_rocksdb
-```
-
-### Parameters
-
-#### `cache_directory`
-
-Specifies the directory under which the filter instance specific RocksDB
-databases will be placed. Note that at startup, each RocksDB database will
-be deleted and recreated. That is, cache content will not be retained across
-MaxScale restarts.
-
-```
-storage_options=cache_directory=/mnt/maxscale-cache
-```
-
-With the above setting a directory `/mnt/macscale-cache/storage_rocksdb` will
-created, under which the actual instance specific cache directories are created.
-
-#### `collect_statistics`
-
-Specifies whether RocksDB should collect statistics that later can be queried
-using `maxadmin`. It should be noted, though, that collecting RocksDB statistics
-is not without a cost.
-From the [RocksDB Documentation](https://github.com/facebook/rocksdb/wiki/Statistics)
-
-_The overhead of statistics is usually small but non-negligible. We usually
-observe an overhead of 5%-10%._
-
-The value is a boolean and the default is `false`.
-
-```
-storage_options=collect_statistics=true
-```
-
 ## Example
 
 In the following we define a cache _MyCache_ that uses the cache storage module