From 6509863373b8391cbb5ad4286403308d0bb5de15 Mon Sep 17 00:00:00 2001 From: Esa Korhonen Date: Thu, 27 Jun 2019 11:40:55 +0300 Subject: [PATCH] Document "enforce_simple_topology"-setting --- Documentation/Changelog.md | 3 ++- Documentation/Monitors/MariaDB-Monitor.md | 18 ++++++++++++++++++ .../MaxScale-2.4.0-Release-Notes.md | 12 ++++++++++++ 3 files changed, 32 insertions(+), 1 deletion(-) diff --git a/Documentation/Changelog.md b/Documentation/Changelog.md index 6c1fed6e7..b2f90f0aa 100644 --- a/Documentation/Changelog.md +++ b/Documentation/Changelog.md @@ -17,7 +17,8 @@ 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: diff --git a/Documentation/Monitors/MariaDB-Monitor.md b/Documentation/Monitors/MariaDB-Monitor.md index 7afc24221..07543619b 100644 --- a/Documentation/Monitors/MariaDB-Monitor.md +++ b/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 diff --git a/Documentation/Release-Notes/MaxScale-2.4.0-Release-Notes.md b/Documentation/Release-Notes/MaxScale-2.4.0-Release-Notes.md index 766cefd40..0995f8dae 100644 --- a/Documentation/Release-Notes/MaxScale-2.4.0-Release-Notes.md +++ b/Documentation/Release-Notes/MaxScale-2.4.0-Release-Notes.md @@ -75,6 +75,11 @@ 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 @@ -302,6 +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)