MySQL MASTER MASTER replication, adding a new Master with out downtime - mysql

I have setup master-master mysql replication in 2 different nodes. Suppose If i am going to add one more node, i.e 3rd master , do I need to have a exactly the same copy of the database in the new server as in the node-1 and node-2 ?
These are high traffic servers and will be keep on updating the database every seconds, so we would like to do it with out downtime. Is there any way to do this, with out downtime ?

MySQL 5.1.18, it is possible to use MySQL Cluster in multi-master replication, including circular replication between a number of MySQL Clusters.
Detailed explanation is explained here:
http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-replication-multi-master.html

Related

Connect and Sync 2 Mysql Databases

Is it possible to sync 2 MYSQL databases so if you write into one it will sync add it to the other one too and other way around? I've seen some Programs that you can use on your local pc but I need a script for example php that I can upload to my vps, it checks every minute for new data and syncs it.
Is that possible?
Are you tried Mysql Replication strategies? See MySQL Replication for High Availability.
Specially Master with Backup Master (Multiple Replication)
or Master with Active Master (Circular Replication or Ring topology)

MySQL backup/restore with master/master replication

I didn't find useful information in documentation that is why I decided to ask.
My environment is as this: Two MySQL servers with Master <-> Mater replication (let's call it Node1 and Node2).
All applications (99%) connects to Node1, on Node2 only one application which is doing INSERTS in a separate DB.
So - changes are propagated to both nodes because of replication. Also because of replication I have relay-bin-logs and bin-logs (on both servers).
I take backup on Node2 using mysqldump
QUESTION:
in case of restore what I need to apply to DB?
only "relay-bin-logs"?
only "bin-logs"?
both?
What is the sequence?
(link to documentation is also appreciated)
Thanks!
P.S. In case of simple MySQL server (without replication) everything is pretty simple - restore from backup and after this apply bin-logs.

access master table from replica

I have two mariadb servers one is configured as master and the other as a replica of this master. I have created a database named params on master and it has a table with a couple of items in it.
How can I see this table and access or modify it using the mysql shell on the replica?
Is this even possible or I have miss understood the replication altogether?
Check that replication works
If you aren't seeing the database on the slave replica, it would be good to check that the output of SHOW SLAVE STATUS doesn't return any errors. A good resource for getting started with replication is the MariaDB KB article on the subject.
When you have confirmed that replication works, you can connect to the slave replica and you should see the database there.
How replication works in MariaDB
Replication in MariaDB will propagate all changes that happen on the master server to any slave servers that are replicating from it. This allows you to read the same data from multiple places without burdening the master server. It does not allow you to seamlessly share data across multiple servers (a Galera cluster offers some of this).
The downside of master-slave replication is that when you want to make a change, you have to make it on the master in order to keep the data consistent across all servers. The benefit of it is the higher availability of your data and increased throughput of read queries. The Replication Overview article has a more detailed description of what replication is and lists some use cases for it.

MySQL replication be bi-directional

We have successfully set up a Master-Slave replication as described in MySQL literature.
However, I'm curious if anyone has set up a bidirectional replication. For example, if one has a Drupal or Wordpress installation. The first ('master') database server goes down, and the secondary ('slave') picks up. All the while, users continue to make edits, writing new data. When the First database server is restarted, can changes written to the Second be replicated upward to the First?
That is: are there other replication strategies than only the Master-Slave?
You can do Master-Master replication. Unfortunately, Neither Drupal or Wordpress support this. The best thing to do is Master-Slave or Master-Slave-Slave, then make the first slave in the chain the new Master if the original master goes down. Then reconfigure the old Master to slave off the new Master (or last slave in the chain).
How often does your mysql server go down?
Master-Master Replication has some disadvantages. For example data inconsistencies can easily occur.
Have you tried synchronous multi-Master Replication with Galera Cluster for MySQL?
http://codership.com/

about mysql high-availability

I read some article about how to implement high-availability solution,the use Heartbeat to check the master mysql is broken,if it broken then switch to the backup server,
one question is when the master server broken,the backup server work on ,how the backup server get the master server 's pre-data
another question is maybe sometimes the master server is not broken,but the mysql service is broken,in this situation is Heartbeat still will switch to the backup server?
What you usually want to do is setup a master-master configuration, but generally only use one master. That was each master also acts as a slave to the other master. In theory, you can modify records in either one and they will keep in sync. In practice, I wouldn't do heavy updates on both servers at once.
My current setup is a master-master configuration, with each master also having a slave off of it. Then you can "failover" to the secondary master/slave and "fail back" when needed. I actually do this if I have database modifications that will take a while.