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Engine Yard is happy to announce Early Access support for Amazon EC2 Elastic Load Balancing (ELB) on Engine Yard Cloud.

Engine Yard Cloud ELB allows you to automatically distribute incoming application traffic across multiple instances. You can enable multiple instances within an Availability Zone (AZ) or distribute your traffic across multiple AZs. If one of your instances becomes unavailable, ELB re-routes traffic to an available healthy instance instead. It then continues to spread the load across remaining healthy instances.

ELB takes some of the load off the app_master (which, by default, balances traffic across all instances using HAProxy). ELB reveals the client's IP address with HTTPS connections (with HAProxy, this requires a stunnel configuration). ELB also allows for multiple SSL certificates in an environment (with HAProxy you must use wildcard certificates; with ELB you can use certificates for multiple domains).

The load balancer supports SSL termination in 3 ways: · ELB - The ELB itself deals with SSL and passes decrypted traffic through to the app instances. This requires an SSL certificate to be uploaded to Amazon (as an ELB SSL Certificate on the SSL Certificates page). This will offload SSL decryption from the app instances and centralize SSL certificate management. · AppServer - This is an SSL passthrough method, where the ELB acts as a TCP proxy, passing SSL requests through to the app instances (which use existing mechanisms for SSL). · Disabled - The ELB does not respond to SSL requests.

Because ELB allows you to associate your domain name in one central place, you can point domain records to the load balancer – rather than specific instances. This allows you to scale up (or down) seamlessly.

ELB also adds extra protection against: · Overloading instances · Downtime in an AZ · Network attacks

If you would like to try out the Engine Yard Cloud ELB feature in Early Access, check out the docs.


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