Updated Readme

Author: mooreandrew

.gitignore

@@ -1 +1,2 @@
 .vagrant
+.yum/x86_64

README.md

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 # mysql-auto-failover
+
+This is a vagrant image which will start a 3 node mysql cluster which is highly available.
+
+### Prerequisite
+
+* Virtualbox
+* Vagrant
+
+### Start the environment
+
+This will load 4 virtual servers:
+
+* Node A (Initial Master)
+* Node B (Slave)
+* Node C (Slave)
+* Controller (Manages Failover)
+
+To start the start the servers do:
+
+```
+vagrant up
+```
+
+### Failover Tutorial
+
+Connect to the Controller and check that the nodes are clustered:
+
+```
+vagrant ssh controller
+sudo bash
+cat log.txt
+```
+
+This should then report the following:
+
+```
+2015-08-12 07:39:27 AM INFO Getting health for master: 192.168.33.10:3306.
+2015-08-12 07:39:27 AM INFO Health Status:
+2015-08-12 07:39:27 AM INFO host: 192.168.33.10, port: 3306, role: MASTER, state: UP, gtid_mode: ON, health: OK
+2015-08-12 07:39:27 AM INFO host: 192.168.33.20, port: 3306, role: SLAVE, state: UP, gtid_mode: ON, health: OK
+2015-08-12 07:39:27 AM INFO host: 192.168.33.30, port: 3306, role: SLAVE, state: UP, gtid_mode: ON, health: OK
+```
+
+This has shown that 192.168.33.10 is the current master and .20 and .30 are the slaves.
+
+Exit out of the controller virtual machine.
+
+To prove replication is working lets add a database to node A (the current master).
+
+```
+vagrant ssh A
+mysql -uroot -ppassword
+CREATE DATABASE failovertest;
+SHOW DATABASES;
+```
+
+This will return a result of:
+
+```
++--------------------+
+| Database           |
++--------------------+
+| information_schema |
+| failovertest       |
+| mysql              |
+| performance_schema |
++--------------------+
+```
+
+Now exit out of node A SSH ('exit' will close the mysql prompt) and connect to node B to check that it as automatically replicated the data.
+
+```
+vagrant ssh B
+mysql -uroot -ppassword
+SHOW DATABASES;
+```
+
+This will then return an identical query result:
+
+```
++--------------------+
+| Database           |
++--------------------+
+| information_schema |
+| failovertest       |
+| mysql              |
+| performance_schema |
++--------------------+
+```
+
+Now exit out of node B SSH.
+
+(If you want, you can repeat this with node C to prove it has replicated to all slaves)
+
+Now to trigger a failover, we will stop the mysql service on node A.
+
+```
+vagrant ssh A
+sudo service mysql stop
+```
+
+This will stop the mysql service on the master, if you exit this and connect to the controller, then you will see the updated status.
+
+```
+vagrant ssh controller
+sudo bash
+cat log.txt
+```
+
+This should then report:
+
+```
+2015-08-12 07:45:54 AM INFO Master may be down. Waiting for 3 seconds.
+2015-08-12 07:46:09 AM INFO Failed to reconnect to the master after 3 attemps.
+2015-08-12 07:46:09 AM CRITICAL Master is confirmed to be down or unreachable.
+2015-08-12 07:46:09 AM INFO Failover starting in 'auto' mode
+2015-08-12 07:46:09 AM INFO Candidate slave 192.168.33.20:3306 will become the new master.
+...
+2015-08-12 07:46:32 AM INFO Getting health for master: 192.168.33.20:3306.
+2015-08-12 07:46:32 AM INFO Health Status:
+2015-08-12 07:46:32 AM INFO host: 192.168.33.20, port: 3306, role: MASTER, state: UP, gtid_mode: ON, health: OK
+2015-08-12 07:46:32 AM INFO host: 192.168.33.30, port: 3306, role: SLAVE, state: UP, gtid_mode: ON, health: OK
+```
+
+Now you can repeat the data replication tasks by connecting to node B and making a change and checking that is appears on node C.
+
+
+### Issues
+
+* If the master goes down, when it comes back up it doesn't rejoin the cluster. I haven't explored this enough to understand why and how to resolve.

Vagrantfile

@@ -4,9 +4,6 @@
 Vagrant.configure(2) do | global |
 #  global.vm.box = "landregistry/centos"
   global.vm.box = "landregistry/centos"
-  if Vagrant.has_plugin?("vagrant-cachier")
-    global.cache.scope = :box
-  end
 
   global.vm.provision "shell", inline: "sed -i -e 's,keepcache=0,keepcache=1,g' /etc/yum.conf"
   #Reenable the line below if the .yum folder is empty