Elasticsearch is widely used to power search experiences across various applications, and optimizing the connection between the application and the Elasticsearch cluster is crucial for user experience. Sniffing is a technique that can enhance this connection by allowing clients to update their connection pools dynamically, based on the current state of the cluster. It involves accessing the _nodes/_all/http endpoint to retrieve a list of nodes, but it is not without challenges, particularly when dealing with different network configurations or cloud providers. Sniffing is beneficial when Elasticsearch clusters are within the same network as the client, but issues may arise if the cluster is behind a load balancer or resides in a separate network. In such cases, configuring Elasticsearch to bind to its host while advertising another address can be a solution, or using a proxy to manage node failures. Sniffing strategies include executing it at startup, on connection failure, periodically, or through custom configurations, each with its advantages depending on the infrastructure. However, it is important to understand the specific setup before implementing sniffing, as it may not always be the optimal approach, especially when using services like Elastic Cloud, which handles these complexities internally.