CODEWITHSUNDEEP
amazon-web-servicesaws-elb
Ashok Reddy
Ashok Reddy

Reputation: 1085

Aws-elb health check failing at 302 code

Hi i created ALB listener 443 and target group instance on 7070 port (not-ssl)

I can access instanceip:7070 without problem , but with https://elb-dns-name not able to access.. instance health check also failed with 302 code

ALB listener port https and instance is http protocol ,

when i browse with https://dns-name it redirecting to http://elb-dns-name

Upvotes: 26

Views: 68254

Answers (7)

user1653042
user1653042

Reputation: 403

In our setup we have a Network Load Balancer (NLB) that forwards traffic to the Application Load Balancer (ALB). In order for the ECS Service (private Subnet which contains an inbound rule for NAT Gateway) to perform the Health Check it needed to call an external endpoint (out), then get a response (in).

The solve was to add an inbound entry to the NLB > Security Group for HTTPS port on the NAT Gateway IP.

Upvotes: 0

Слава ЗСУ
Слава ЗСУ

Reputation: 495

In my case I had a domain www.domain.com

but by default when you accessing the domain and you are not logged in you are immediately redirected to www.domain.com/login

... and that is something that caused the problem

So you have 2 options:

  1. Go to your aws target group -> health check and change your default path / to the new one which in my case was /login. I'm really sure if login endpoint works - website works too.

  2. Go to your aws target group -> health check and change your default status code from 200 to 200,301,302(added two redirecting status codes). It is definitely less appropriate way but still acceptable, depends on the case

Upvotes: 4

Igor
Igor

Reputation: 688

I stuck with the same problem in AWS ALB (Health checks failed with these codes: [302]) Configuration:

  • Tomcat 9 servers that are listening on port 80 only
  • ALB health check path was set to "/my_app_name" expecting to serve health check from the application's root index page.

My configured health page is not expected to do any redirects, but to return HTTP/200 if server is healthy and HTTP/500 if unhealthy.

The proposed solution just to add HTTP/302 as a success code is absolutely WRONG and misleading. It means that the page's internal health check logic isn't run, as HTTP/302 redirect code just shows common ability of the server to respond.

The problem was in Tomcat server itself that in the case of request to "/my_app_name" was redirecting with HTTP/302 to "/my_app_name/" (pay attention to the slash at the end).

So setting health check path to "/my_app_name/" fixed the problem, health check logic runs well and HTTP/200 is returned.

Upvotes: 9

ahmadrg
ahmadrg

Reputation: 11

I had a similar case where I'm offloading TLS on the ELB and then sending traffic to port 80 with plain HTTP. I'm always getting the 302 code from the ELB.

You can change the status code for the target group and specify the success code as 302, but I don't think that is a very good idea. Since you may encounter a different status code if you changed some configuration in your Apache or htaccess files which may cause your instance to put out of service. The goal of Health Check is identify faulty servers and remove them from the production environment.

This solution worked great for me: https://stackoverflow.com/a/48140513/14033386

Cited below with more explanation:

Enable the mod_rewrite module. In most Linux distros it's enabled by default when you install Apache. But check for it anyway. Check this: https://stackoverflow.com/a/5758551/14033386

LoadModule rewrite_module modules/mod_rewrite.so

and then add the following to your virtual host.

ErrorDocument 200 "ok"
RewriteEngine On
RewriteRule "/AWS-HEALTH-CHECK-URL" - [R=200]

AWS-HEALTH-CHECK-URL is the one you specify in the health check settings.

AWS EC2 - Target Groups - YOUR_GROUP - Health Checks

This solution will always return 200 code that specific URL as long as your server is active and serving requests.

Upvotes: 1

Moadh
Moadh

Reputation: 25

I run into the same issue recently, and as suggested by @SudharsanSivasankaran we have edited the health check settings at the target level.

But we have kept the 200 only status code and instead updated the path to directly hit the page the redirection goes to.

For instance if a website hosted under instance:80 needs the user to be logged on and redirect it to the /login page, all we need to do is add the /login path in the health check.

Upvotes: 2

ASHUTOSH TEKNUR
ASHUTOSH TEKNUR

Reputation: 49

add this annotation in your ingress controller it will modify the success code and nodes will be in healthy state.

alb.ingress.kubernetes.io/success-codes: 200,404,301,302

Upvotes: 2

Sudharsan Sivasankaran
Sudharsan Sivasankaran

Reputation: 5897

you get 302 when performing URL redirection, any ELB Health check will look for success code 200 for the health check to pass. In ALB, this can be configured under health check in the ELB console.

To modify the health check settings of a target group using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
  2. On the navigation pane, under LOAD BALANCING, choose Target Groups. Select the target group.
  3. On the Health checks tab, choose Edit.
  4. On the Edit target group page, modify the setting Success Codes to 302 or as needed, and then choose Save.

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Upvotes: 55

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