Update filter documentation

- Add note about filters having become available in 2.1.
- Add insertstream to release notes and change log.
- Add complete example to cache documentation.

Documentation/Filters/CCRFilter.md

@@ -1,5 +1,7 @@
 # Consistent Critical Read Filter
 
+This filter was introduced in MariaDB MaxScale 2.1.
+
 ## Overview
 
 The Consistent Critical Read (CCR) filter allows consistent critical reads to be

Documentation/Filters/Cache.md

@@ -1,5 +1,7 @@
 # Cache
 
+This filter was introduced in MariaDB MaxScale 2.1.
+
 ## Overview
 The cache filter is a simple cache that is capable of caching the result of
 SELECTs, so that subsequent identical SELECTs are served directly by MaxScale,
@@ -8,6 +10,11 @@ without the queries being routed to any server.
 _Note that the cache is still experimental and that non-backward compatible
 changes may be made._
 
+Note that installing the cache causes all statements to be parsed. The
+implication of that is that unless statements _already_ need to be parsed,
+e.g. due to the presence of another filter or the chosen router, then adding
+the cache will not necessarily improve the performance, but may decrease it.
+
 ## Limitations
 
 All of these limitations may be addressed in forthcoming releases.
@@ -639,3 +646,44 @@ 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
+`storage_inmemory` and whose _soft ttl_ is `30` seconds and whose _hard ttl_ is
+`45` seconds. The cached data is shared between all threads and the maximum size
+of the cached data is `50` mebibytes. The rules for the cache are in the file
+`cache_rules.json`.
+
+### Configuration
+```
+[MyCache]
+type=filter
+module=cache
+storage=storage_inmemory
+soft_ttl=30
+hard_ttl=45
+cached_data=shared
+max_size=50Mi
+rules=cache_rules.json
+
+[MyService]
+type=service
+...
+filters=MyCache
+```
+
+### `cache_rules.json`
+The rules specify that the data of the table `sbtest` should be cached.
+
+```
+{
+    "store": [
+        {
+            "attribute": "table",
+            "op": "=",
+            "value": "sbtest"
+        }
+    ]
+}
+```

Documentation/Filters/Insert-Stream-Filter.md

@@ -1,5 +1,8 @@
 # Insert Stream Filter
 
+This filter was introduced in MariaDB MaxScale 2.1.
+
+## Overview
 The _insertstream_ filter converts bulk inserts into CSV data streams that are
 consumed by the backend server via the LOAD DATA LOCAL INFILE mechanism. This
 leverages the speed advantage of LOAD DATA LOCAL INFILE over regular inserts

Documentation/Filters/Masking.md

@@ -1,5 +1,7 @@
 # Masking
 
+This filter was introduced in MariaDB MaxScale 2.1.
+
 ## Overview
 With the _masking_ filter it is possible to obfuscate the returned
 value of a particular column.

Documentation/Filters/Maxrows.md

@@ -1,5 +1,7 @@
 # Maxrows
 
+This filter was introduced in MariaDB MaxScale 2.1.
+
 ## Overview
 The maxrows filter is capable of restricting the amount of rows that a SELECT,
  a prepared statement or stored procedure could return to the client application.