Name a technique used for ensuring high availability in integration systems.

Load balancing is a technique that distributes incoming network traffic or workload across multiple servers or resources in an integration system. This approach helps ensure high availability by preventing any single server from becoming a bottleneck or point of failure, thus improving the overall performance and reliability of the system.

When a user makes a request, load balancers can intelligently route that request to the least busy or most available server. This not only helps maintain responsiveness during peak loads but also ensures that if one server goes down or becomes unresponsive, alternatives are immediately available to handle the requests. Consequently, the system remains operational and user experience is maintained.

In contrast, containerization, while effective for resource management and scalability, primarily focuses on deploying applications in a lightweight, portable manner. Code optimization and database indexing improve performance and efficiency but do not directly address the high availability aspect of systems. High availability emphasizes ongoing accessibility and uptime, which load balancing directly facilitates.