If you need a High Availability (HA) setup to balance connections to your MariaDB cluster nodes, you should consider using HAProxy. HAProxy set up in a dual configuration (primary and secondary) will further contribute to your redundant HA topology. This blog is intended to describe how the key component in the dual HAProxy configuration works to ensure an HA solution. <\/p>\n\n\n\n
The key component for this solution is the There are a lot of geeky, low-level details involved in how the Heartbeat Monitoring: <\/strong> Service Checking: <\/strong>In addition to monitoring the health of the nodes themselves, Failover Handling:<\/strong> If keepalived<\/code> daemon. This important daemon is often used in conjunction with HAProxy to provide failover capability and ensure the high availability of HAProxy services. keepalived is an open-source software package used along with HAProxy to provide simple and robust facilities for load balancing and high availability in Linux-based environments. It works by monitoring the health of dual HAProxy nodes and automatically transferring service responsibility from the primary node to the secondary node in case of failure. <\/p>\n\n\n\nkeepalived<\/code> works, but this blog’s intention is to keep it simple. Below is a simple detailed description of what the keepalived daemon does in a HAProxy dual setup:<\/p>\n\n\n\nkeepalived<\/code> continuously monitors the health of each node in the HAProxy dual setup by periodically sending heartbeat messages between the nodes. These heartbeat messages verify that each node is operational and able to respond.<\/p>\n\n\n\nkeepalived<\/code> also checks the health of the services running on each node. For example, it can monitor the availability of HAProxy instances by checking whether they are responsive and able to handle incoming requests.<\/p>\n\n\n\nkeepalived<\/code> detects that a node or a service on a node has failed or become unreachable, it initiates failover procedures to ensure that services remain available. This typically involves transferring the responsibility for handling incoming requests from the failed node to the secondary or active node HAProxy.<\/p>\n\n\n\n