Replication

Replication Configuration

replication-manager to failover will be in charge of rebuilding the replication, following section explore how to proceed with it.

replication-credential (2.0), rpluser (0.6)
Item Value
Description Replication is created with such credential, in the [user]:[password] format.
Type string
Default Value repl:repman
replication-use-ssl (1.0)
Item Value
Description Replication is created using SSL encryption to replicate from master.
Type boolean
Default Value false
replication-master-connect-retry (2.0), master-connect-retry (1.0)
Item Value
Description Replication is created using this connection retry timeout in second.
Type integer
Default Value 10

Topology Configuration

Master Slaves Configuration

replication-manager supports 2-node master slave setup, it is advice to use at least 3 nodes cluster to get the cluster tolerant to losing or stopping a slave.

By default replication-manager assume a flat topology but can enable multi-tier topology with some additional setting, scenario is you stop a slave and his master die, when the master rejoin the topology it can keep his slave under him instead of switching the slave to the new master

replication-multi-tier-slave (2.0), multi-tier-slave (1.0)
Item Value
Description Enable relay slaves topology
Type boolean
Default Value false

Multi Tier Slaves Configuration

replication-multi-tier-slave (2.0), multi-tier-slave (1.0)
Item Value
Description Enable relay slaves topology
Type boolean
Default Value false

replication-manager have support for replication tree or relay slaves architecture, in case of master death one of the slaves under the relay is promoted as a master.

replication-manager does not manage yet the relay crash to replace it with a slave

Multi Master Configuration

replication-manager supports 2-node multi-master topology detection. It is required to declare it the configuration configuration

replication-multi-master (2.0), multimaster (0.7)
Item Value
Description Enable Master-Master topology
Type boolean
Default Value false

You just need to set one preferred master

We advice to enable restart of database in read-only mode to cover the case where a failed node try to rejoin but can't be contacted anymore from replication-manager, in such case no write traffic will be enable on the rejoining node.In a Multi DC split brain with a proxy on each side we can simply ensure the split brain will not make the database diverge on each side

MariaDB configuration file: 

read_only = 1

This flag ensures that in case of split brain + leader crash, when old leader is reintroduced it will not show up as a possible leader for WRITES.

MaxScale configuration file:

Maxscale need to be instructed to monitor multi master, following setting track the read-only flag and route queries to the writable node.

[Multi-Master Monitor]
type=monitor
module=mmmon
servers=server1,server2,server3
user=myuser
passwd=mypwd
detect_stale_master=true

Multi Source or Channel Configuration

replication-manager support monitoring of a specific replication channel, those feature are experimental and should be tested because they are not covered by QA

replication-source-name (2.0), master-connection (1.1)
Item Value
Description Replication channel name to use for multisource
Type string
Default Value ""

Multi Master Ring Configuration

replication-multi-master-ring (2.0)
Item Value
Description Enable Multi Master Ring topology
Type boolean
Default Value false

Read more

Multi Master Galera Configuration

replication-multi-master-wsrep (2.0)
Item Value
Description Enable Multi Master Galera
Type boolean
Default Value false

Read more