What is 'Draining' a server?

Updated Apr 28, 2026

Short answer

The process of stopping new requests to a server while allowing existing active connections to complete before maintenance.

Deep explanation

Mid-level load balancing involves optimization and protocol handling. SSL Offloading is a huge win for application performance. However, architects must decide between SSL Termination (decrypt at LB) and SSL Passthrough (decrypt at server) based on security requirements.

Real-world example

An e-commerce site terminating SSL at a Cloud Load Balancer to perform URL-based routing to 'Checkout' vs 'Catalog' services.

Common mistakes

  • Relying on DNS Round Robin for high availability without a low TTL, leading to 15-minute outages when a server dies.

Follow-up questions

  • What is SNI (Server Name Indication)?

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