Merge branch '2.4.0' into 2.4

Documentation/Changelog.md

@@ -17,7 +17,9 @@
   by adding the `--rdns`-option to the command.
 * The following MariaDB-Monitor settings have been removed and cause a startup error
   if defined: `mysql51_replication`, `multimaster` and `allow_cluster_recovery`. The
-  setting `detect_replication_lag` is deprecated and is ignored.
+  setting `detect_replication_lag` is deprecated and ignored.
+* `enforce_simple_topology`-setting added to MariaDB-Monitor.
+* The mqfilter has been deprecated.
 
 For more details, please refer to:
 

Documentation/Filters/RabbitMQ-Filter.md

@@ -2,6 +2,9 @@
 
 ## Overview
 
+The **mqfilter** has been deprecated in MaxScale 2.4 and it will be removed
+in a future version of MaxScale. We advise against using it.
+
 This filter is designed to extract queries and transform them into a canonical
 form e.g. `INSERT INTO database.table VALUES ("John Doe", "Downtown",100,50.0);`
 turns into `INSERT INTO database.table VALUES ("?", "?",?,?);`. The filter

Documentation/Monitors/MariaDB-Monitor.md

@@ -30,6 +30,7 @@ Table of Contents
         * [auto_failover](#auto_failover)
         * [auto_rejoin](#auto_rejoin)
         * [switchover_on_low_disk_space](#switchover_on_low_disk_space)
+        * [enforce_simple_topology](#enforce_simple_topology)
         * [replication_user and replication_password](#replication_user-and-replication_password)
         * [failover_timeout and switchover_timeout](#failover_timeout-and-switchover_timeout)
         * [verify_master_failure and master_failure_timeout](#verify_master_failure-and-master_failure_timeout)
@@ -644,6 +645,23 @@ must be defined for the monitor.
 switchover_on_low_disk_space=true
 ```
 
+#### `enforce_simple_topology`
+
+This setting tells the monitor to assume that the servers should be arranged in a
+1-master-N-slaves topology and the monitor should try to keep it that way. If
+`enforce_simple_topology` is enabled, the settings `assume_unique_hostnames`,
+`auto_failover` and `auto_rejoin` are also activated regardless of their individual
+settings.
+
+This setting also allows the monitor to perform a failover to a cluster where the master
+server has not been seen [Running]. This is usually the case when the master goes down
+before MaxScale is started. When using this feature, the monitor will guess the GTID
+domain id of the master from the slaves. For reliable results, the GTID:s of the cluster
+should be simple.
+```
+enforce_simple_topology=true
+```
+
 #### `replication_user` and `replication_password`
 
 The username and password of the replication user. These are given as the values

Documentation/Release-Notes/MaxScale-2.4.0-Release-Notes.md

@@ -75,11 +75,29 @@ The `ndbclustermon` module has been removed.
 The `mmmon` module has been removed as the `mariadbmon` monitor largely does
 what it used to do.
 
+### MariaDB-Monitor settings
+
+The following settings have been removed and cause a startup error
+if defined: `mysql51_replication`, `multimaster` and `allow_cluster_recovery`.
+
 ### `log_to_shm`
 
 The `log_to_shm` parameter that was removed in 2.3 will be treated as an unknown
 parameter in 2.4.0.
 
+## Deprecated Features
+
+### `mqfilter`
+
+The `mqfilter` has been deprecated and it will be removed in a future version
+of MaxScale.
+
+We advise against using it.
+
+### Nagios Plugins
+
+MaxScale no longer ships the example scripts and configuration files for Nagios.
+
 ## New Features
 
 ### Clustrix Support
@@ -289,6 +307,13 @@ is done directly from a remote master server. This skips the binlogrouter
 definition completely making the conversion process faster and more space
 efficient.
 
+### `enforce_simple_topology`
+
+This MariaDB-Monitor setting allows the monitor greater freedom in managing the
+backend servers. Please see
+[MariaDB-Monitor documentation](../Monitors/MariaDB-Monitor.md#enforce_simple_topology)
+for more information.
+
 ## Bug fixes
 
 [Here is a list of bugs fixed in MaxScale 2.4.0.](https://jira.mariadb.org/issues/?jql=project%20%3D%20MXS%20AND%20issuetype%20%3D%20Bug%20AND%20status%20%3D%20Closed%20AND%20fixVersion%20%3D%202.4.0)

Documentation/Routers/Avrorouter.md

@@ -24,6 +24,44 @@ streams from a database table.
 
 [TOC]
 
+## Direct Replication Mode
+
+MaxScale 2.4.0 added a direct replication mode that connects the avrorouter
+directly to a MariaDB server. This mode is an improvement over the binlogrouter
+based replication as it provides a more space-efficient and faster conversion
+process.
+
+To enable the direct replication mode, add either the `servers` or the `cluster`
+parameter to the avrorouter service. The avrorouter will then use one of the
+servers as the replication source. In this mode the `source` parameter is
+ignored as there is no need for a source service.
+
+Here is a minimal avrorouter direct replication configuration:
+
+```
+[maxscale]
+threads=auto
+
+[server1]
+type=server
+address=127.0.0.1
+port=3306
+protocol=MariaDBBackend
+
+[cdc-service]
+type=service
+router=avrorouter
+servers=server1
+user=maxuser
+password=maxpwd
+
+[cdc-listener]
+type=listener
+service=cdc-service
+protocol=CDC
+port=4001
+```
+
 ## Configuration
 
 For information about common service parameters, refer to the
@@ -33,7 +71,8 @@ For information about common service parameters, refer to the
 
 #### `source`
 
-The source for the binary logs. This is an optional parameter.
+The source for the binary logs. This is an optional parameter and is ignored if
+the router is configured in direct replication mode.
 
 **Note:** If the `source` parameter is defined the values for `binlogdir` and
   `filestem` are only read from the source service. This means that the