From 3331c42aeeb89ec52fa050cde5fd0748fbc01834 Mon Sep 17 00:00:00 2001 From: Magnus Kulke Date: Tue, 11 Oct 2016 23:42:23 +0200 Subject: [PATCH] Added ALB Gotcha about unhealthy targets "If no Availability Zone contains a healthy target, the load balancer nodes route requests to all targets." source: http://docs.aws.amazon.com/elasticloadbalancing/latest/application/target-group-health-checks.html --- README.md | 1 + 1 file changed, 1 insertion(+) diff --git a/README.md b/README.md index 7c2887f0..ae8c2fe4 100644 --- a/README.md +++ b/README.md @@ -879,6 +879,7 @@ ALB - ALBs do not (yet) support routing based on HTTP “Host” header or HTTP verb. - Instances in the ALB's target groups have to either have a single, fixed healthcheck port (“EC2 instance”-level healthcheck) or the healthcheck port for a target has to be the same as its application port (“Application instance”-level healthcheck) - you can't configure a per-target healthcheck port that is different than the application port. - ALBs are VPC-only (they are not available in EC2 Classic) +- In a target group, if there is no healthy target, all requests are routed to all targets. An example: you add a target group containing a single service (with a long init phase maybe) as target to a listener, it does not pass health checks (yet), requests will still reach your (initializing) service. Elastic IPs -----------