Running MariaDB in a Hybrid Cloud Setup

The term “hybrid” is popular  nowadays. Hybrid is used for vehicles, applications, financials, and also cloud. For example, in the vehicle’s use case, the hybrid means combining the power of the gasoline engine with an electric motor.

In the hybrid cloud environment, we combine and connect the resources between a private cloud or on-prem environment with the public cloud. One popular use case is to mirror an on-prem environment in the cloud for disaster recovery purposes. There are some points you need to consider when building a Hybrid Cloud database. Latency will determine which MariaDB architecture you can use. A reliable connection with low and predictable latency means you can spread one Galera Cluster across both environments, with the DR setup in the cloud being syncronously up-to-date with your on-prem environment. However, this also means that the performance of the entire cluster will be limited by the performance of the slowest node in the cluster.

Another alternative is to have two separate systems that are connected using regular asynchronous replication. For instance, it is possible to have two MariaDB Galera clusters asynchronously replicate with each other. For those who prefer the standard asynchrnous replication, we propose two master-slave setups, with the second setup replication from the first one.

In this blog, we will provide a quick hands on guide on how to run a highly available MariaDB replicated setup in a Hybrid Cloud environment.

Why Hybrid Cloud?

Hybrid Cloud enables enterprise organizations to mix the environment between the private on-prem and public cloud.  This model provides the following benefits for the organization :

• Scalability of infrastructure

You can quickly scale the infrastructure by combining private cloud and public cloud as the business rapidly grows. The public cloud offers a cost effective way to extend your infrastructure, while in a private setup, it requires upfront planning and CAPEX.

• Disaster Recovery 

A hybrid cloud can be categorized as having a Disaster Recovery Plan, with regards to the deployment model. Public clouds can be used as disaster recovery sites, if something happens to the private datacenter (eg. force majeure, data center issue).

• Better technical control and security

By having a hybrid cloud environment, organizations are able to segregate environments. Share the load of services based on restricted access and also enable multi tenancy and segregating the layer.

• Architectural Flexibility

Running hybrid cloud environments gives you flexibility in how you can design services based on the workload and the requirements from the application side. For example, a private cloud environment can be restricted with regards to access to Internet, except to a public cloud environment via VPN, while the public cloud environment handles communication to the third party services.

Connectivity

Running a hybrid cloud for databases needs a secure communication link between the private cloud and public cloud. Most of the cloud providers have some sort of connectivity option available, for instance AWS has AWS Direct Connect.

Achieving Hybrid Cloud using ClusterControl

There are a few deployment models for MariaDB in hybrid cloud environments. We can use MariaDB Master/Slave replication or MariaDB Galera Cluster. The difference between Master/Slave and Galera Cluster is the synchronization method. Master/Slave replication uses asynchronous replication of data that is written to a binlog, while MariaDB Galera Cluster uses “virtually” synchronous replication by broadcasting writesets to all nodes. It is also possible to have separate Galera Clusters replicate asynchronously via standard replication.

Deployment of MariaDB Master/Slave Replication on hybrid cloud in ClusterControl is straightforward. You just go through Deploy menu as shown below:

After clicking Deploy, choose MySQL Replication and fill the SSH user, password, and Cluster Name as shown below:

Then click Continue. Choose MariaDB as the database vendor and version to be installed. There are custom options for data directory and server port, or can use the default values.

Fill in the root password for the database, and then click Continue. Add the IP Addresses of the hosts on private and public clouds as shown below:

Note that you will need to take care of the connectivity between the private and public environments, and make sure it is secure. Then click Deploy, it will deploy MariaDB Master/Slave Replication in your hybrid cloud environment. Both environments will have a replicated setup, and the DR setup in the public cloud will be replicating asynchronously from the primary setup in your private datacenter.