I have a Load Balancer setup that routes traffic to multiple Cloud Storage buckets and an instance group for backend. The buckets seem to work fine but I just can't get the instance group to work. The instance works fine when I use it's public IP. But it just won't work through the load balancer.
This is my second time setting up the exact same deployment so not entirely sure where I went wrong. I looked at the documentation for troubleshooting, looks like something is wrong with my health check.
I have configured a health check which should work though, I set it to http port 80 / path. My server is returning 200 response code for that but for some reason, in the load balancer page, I can see the column "healthy" as 0/0 and in the backend service page, I can see 0 of 1 instances healthy.
I even tried adding firewall rules for health check but still no luck.
Then I tried to get the health status using cloud shell and I get an empty status, not even failed, just empty. below is the result I got from cloud shell
backend: https://www.googleapis.com/compute/v1/projects/project-name/zones/asia-southeast1-b/instanceGroups/prod-instance-group
status:
kind: compute#backendServiceGroupHealthkind:
compute#backendServiceGroupHealth
This got resolved overnight. I guess there was some issue with GCP itself, I didn't change a thing and now it shows Healthy 1/1 and works perfectly.
I guess GCP load balancer is just unstable.
I created a REST AWS API Gateway and it worked perfectly when it was targeting a single ec2 instance. I then went on to set it up with an EC2 Load Balancer for a Target Group with 2 EC2 instances. Now when I make a request that I synchronously get the status of, I get a 404 error. My guess is that the initial job was posted on one machine and then I try to access it on the other machine yielding a 404 error. I tried to enable stickiness to the target group, but that did nothing. Any suggestions?
Stickiness config
I would suggest you to check the logs on your EC2 instances and see which is the exact request routed from the LB to the EC2 machine. My experience is that LB calls the EC2 instances using their internal IP address and the URL might be modified, based on configuration.
Checking the logs will help you debug this error. With stickness you're doing good.
We have 3 EC2 Instances(Apache Web Server) running under AWS ELB, it sharing load correctly but whenever any of Web Server down i.e. Web1 having some issue i.e. Disk Full or Apache Crash then still ELB trying to send request to that server which is already not responding or don't have capacity to respond, hence user who is connected to that server are getting error.
Question : Is there way to identify Fail server and force ELB to stop passing request to failed server?
FYI: Auto Scaling is not enabled.
You need to configure health checks for your ELB. When the checks are failing, the elb will stop forwarding traffic to the unhealthy instance.
I have an ELB setup for my Magento2 application. The application is running on EC2 instances. In Magento 2 I need to specify a base url for the site. I am setting that as my load balancer public dns.
When the ELB performs Health Checks on the individual EC2 Instances they are returning a 302 as magento is trying to redirect the call to the public dns record for the ELB.
How do I deal with this?
I created a file health.html and placed this in the root magento folder on the EC2 instances.
I updated the health check to load /health.html.
This works fine and the Load Balancers are able to direct traffic to these instances as they are healthy.
This is not really ideal and mainly served to verify configurations between M2 and the ELB and EC2 instances.
I would like the health check to make sure Magento2 is actually healthy.
You could assign the health endpoint to a magento action directly.
I updated the health check to load /health.html.
Set that to an HTTP request declared in your Application routes, and add your checks there. /health/action for example.
I found the answer, There is a setting in Stores->Configuration->General->Web->Url-Options that allows you to turn off the auto redirect. I disabled this and the checks are now working
I am trying to set up Elastic Load Balancing (ELB) in AWS to split the requests between multiple instances. I have created several images of my webserver based on the same AMI, and I am able to ssh into each individually and access the site via each distinct public DNS.
I have added each of my instances to the load balancer, but they all come back with the Status: Out of Service because they failed the health check. I'm mostly confused because I can access each instance from its public DNS, but I get a timeout whenever I visit the load balancer DNS name.
I've been trying to read through all the docs and googling it, but I'm stuck. Any pointers or links in the right direction would be greatly appreciated.
I contacted AWS support about this same issue. Apparently their system doesn't know how to handle cases were all of the instances behind the ELB are stopped for an extended amount of time. AWS support can manually refresh the statuses, if you need them up immediately.
The suggested fix it to de-register the ec2 instances from the ELB instead of just stopping them and re-register them when you start again.
Health check is (by default) made by accessing index.html on each instance incorporated in load balancer. If you don't have index.html in document root of instance - default health check will fail. You can set custom protocol, port and path for health check when creating elastic load balancer.
Finally I got this working. The issue was with the Amazon Security Groups, because I've restricted the access to port 80 to few machines on my development area and the load balancer could not access the apache server on the instance. Once the load balancer gained access to my instance, it gets In Service.
I checked it with tail -f /var/log/apache2/access.log in my instance, to verify if the load balancer was trying to access my server, and to see the answer the server is giving to the load balancer.
Hope this helps.
If your web server is running fine, then it means the health check goes on a url that doesn't return 200.
A trick that works for me : go on the instance, type curl localhost:80/pathofyourhealthcheckurl
After you can adapt your health check url to always have a 200 response.
In my case, the rules on security groups assigned to the instance and the load balancer were not allowing traffic to pass between the two. This caused the health check to fail.
I to faced same issue , i changed Ping Protocol from https to ssl .. it worked !
Go to Health Check --> click on Edit Health Check -- > change Ping protocol from HTTPS to SSL
Ping Target SSL:443
Timeout 5 seconds
Interval 30 seconds
Unhealthy Threshold 5
Healthy Threshold 10
For anyone else that sees this thread as this isn't listed:
Check that the health check is checking the port that the responding server is listening on.
E.g. node.js running on port 3000 -> Point healthcheck to port 3000;
Not port 80 or 443. Those are what your ALB will be using.
I spent a morning on this. Yes.
I would like to provide you a general way to solve this problem. When you have set up you web server like apache or nginx, try to read the access log file to see what happened. In my occasion, it report 401 error because I have add the basic auth in nginx. Of course, just like #ivankoni remind, it may because of the document you check is not exist.
I was working on the AWS Tutorial on hosting a web app and ran into this problem. Step 7b states the following:
"Set Ping Path to /. This sends queries to your default page, whether
it is named index.html or something else."
They could have put the forward slash in quotations like this "/". Make sure you have that in your health checks and not this "/." .
Adding this because I've spent hours trying to figure it out...
If you configured your health check endpoint but it still says Out of Service, it might be because your server is redirecting the request (i.e. returning a 301 or 302 response).
For example, if your endpoint is supposed to be /app/health/ but you only enter /app/health (no trailing slash) into the health check endpoint field on your ELB, you will not get a 200 response, so the health check will fail.
I had a similar issue. The problem appears to have been caused due to my using a HTTP health check and also using .htaccess to password protect the site.
I got the same error, in my case had to copy the particular html file from s3 bucket to "/var/www/html" location. The same html referenced in load balancer path.
The issue resolved after copying html file.
I had this issue too, and it was due to both my inbound and outbound rule for the Load Balancer's Security Group only allowing HTTP traffic on port 80. I needed to add another rule for HTTPS traffic on port 443.
I was also facing that same issue,
where ELB (Classic-Load-Balancer) try to request /index.html not / (root) while health check.
If it unable to find /index.html resource it says 'OutOfService'. Be Sure index.html should be available.