Add insertstream documentation

The documentation explains how the filter works.

Documentation/Documentation-Contents.md

@@ -87,6 +87,7 @@ Here are detailed documents about the filters MariaDB MaxScale offers. They cont
  - [RabbitMQ Filter](Filters/RabbitMQ-Filter.md)
  - [Named Server Filter](Filters/Named-Server-Filter.md)
  - [Luafilter](Filters/Luafilter.md)
+ - [Insert Stream Filter](Filters/Insert-Stream-Filter.md)
 
 ## Monitors
 

Documentation/Filters/Insert-Stream-Filter.md

@@ -0,0 +1,84 @@
+# Insert Stream Filter
+
+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
+while also reducing the overall network traffic by condensing the inserted
+values into CSV.
+
+## Filter Parameters
+
+This filter has no parameters.
+
+## Details of Operation
+
+The filter translates all INSERT statements done inside an explicit transaction
+into LOAD DATA LOCAL INFILE streams. The file name used in the request will
+always be _maxscale.data_.
+
+The following example is translated into a LOAD DATA LOCAL INFILE request
+followed by two CSV rows.
+
+```
+BEGIN;
+INSERT INTO test.t1 VALUES (1, "hello"), (2, "world");
+COMMIT;
+```
+
+Multiple inserts to the same table are combined into a single stream. This
+allows for efficient bulk loading with simple insert statements.
+
+The following example will use only one LOAD DATA LOCAL INFILE request followed
+by four CSV rows.
+
+```
+BEGIN;
+INSERT INTO test.t1 VALUES (1, "hello"), (2, "world");
+INSERT INTO test.t1 VALUES (3, "foo"), (4, "bar");
+COMMIT;
+```
+
+Non-INSERT statements executed inside the transaction will close the streaming
+of the data. Avoid interleaving SELECT statements with INSERT statements inside
+transactions.
+
+The following example has to use two LOAD DATA LOCAL INFILE requests, each
+followed by two CSV rows.
+
+**Note:** Avoid doing this!
+
+```
+BEGIN;
+INSERT INTO test.t1 VALUES (1, "hello"), (2, "world");
+SELECT * FROM test.t1;
+INSERT INTO test.t1 VALUES (3, "foo"), (4, "bar");
+COMMIT;
+```
+
+### Estimating Network Bandwidth Reduction
+
+The more inserts that are streamed, the more efficient this filter is. The
+saving in network bandwidth in bytes can be estimated with the following
+formula:
+
+```
+((20 + t) * n) + (n * (m * 2)) - 108 - t = x
+
+n = Number of INSERT statements
+m = Number of values in each insert statement
+t = Length of table name
+x = Number of bytes saved
+```
+
+Positive values indicate savings in network bandwidth usage.
+
+## Example Configuration
+
+The filter has no parameters so it is extremely simple to configure. The
+following example shows the required filter configuration.
+
+```
+[Insert-Stream]
+type=filter
+module=insertstream
+```