I read the aws documentation inside the elastic beanstalk program where aws is responsible for scaling the servers and auto managing it. In the same documentation there is an option for changing and configuring the load balancer. In my case I want to change it to balance the requests that come to the servers on the IP network layer (L3), but it says that only HTTP and TCP can be listened and balanced.
I am developing a chat application backend that need to be developed with scaling in considerations. how can I configure the load balancer to listen on L3 ?
the chat application in order to work it must make the tcp connection with the server not the load balancer so that's why I must load the packets on the IP layer to the server so the server can establish a tcp connection with the app ( if I am wrong and I can do it on the tcp layer tell me ).
If I can't, does that give me another option or I will just be forced on using ec2 and handle all the system management overhead myself and create my own load balancer ?
ELB Classic operates at either Layer 4 or Layer 7. Those are the options.
the chat application in order to work it must make the tcp connection with the server not the load balancer so that's why I must load the packets on the IP layer to the server so the server can establish a tcp connection with the app.
You're actually incorrect about this. If you need to know the client's source IP address, you can enable the Proxy Protocol on your ELB, and support this in your server code.
When the ELB establishes each new connection to the instance, with the Proxy Protocol enabled, the ELB emits a single line preamble containing the 5-way tuple describing the external connection, which your application can interpret. Then it opens up the L4 connection's payload streams and is transparent for the remainder of the connection.
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/enable-proxy-protocol.html
Related
I've set up a TCP network load balancer, as described here: https://cloud.google.com/load-balancing/docs/network. I need to balance traffic from anywhere on the internet to my backend VMs, running a custom application listening to a non-standard TCP port.
Everything seems to work initially, but after about 10 seconds the connected clients are disconnected, reporting the error "An existing connection was forcibly closed by the remote host.". For debugging I allow my backend VMs to have public IPs and when connecting to any of them directly, bypassing the load balancer, everything works and there's no disconnect.
As I understand it, this load balancer setup I'm using should be pass through: Once the backend VM is selected, the TCP connection should essentially be with the back end VM and the load balancer no longer involved. The backend VMs are certainly not terminating the connection forcibly - as far as the backends are concerned, the connection persists after the client disconnect and time out later. The timeout settings described for other google cloud load balancers don't seem to apply to External TCP/UDP Network Load Balancing.
What am I missing?
TCP/UDP network load balancers are pass-through load balancers and do not proxy connections to your backend instances, so your backends receive the original client request. The network load balancer doesn't do any Transport Layer Security (TLS) offloading or proxying. Traffic is directly routed to your VMs.
Confirm that your network load balancer is set up correctly using these
steps.
Ensure that server software running on your backend VMs is listening on the IP address of the load balancer's forwarding rule.
Make sure you’ve configured firewall rules using source IP ranges for Network load balancing health checks.
Additionally, you can capture tcpdump to narrow down your issue, which may provide information to specific resource.
I'm getting gateway time-outs when trying to use a port specifically for websockets using an Application Load Balancer inside an Elastic Beanstalk environment.
The web application and websocket server is held within a Docker container, the application runs fine however wss://domain.com:8080 will just time out.
Here is the Load balancer listeners, using the SSL cert for wss.
The target group it points to is accepting 'Protocol' of HTTP (I've tried HTTPS) and forwards to 8080 onto an EC2 instance. Or.. It should be. (Doesn't appear to be an option for TCP on Application Load Balancers).
I've had a look over the Application Load Balancer logs and it looks like the it reaches the target group, but times out between it's connection to the EC2 instance, and I'm stumped on why.
All AWS Security Groups have been opened on all traffic for the time being, I've checked the host and found that the port is open and being listened to by Nginx which will route to the correct port to the docker container:
docker ps also shows me:
And once inside the container I can see that the port is being listened to by the Websocket server:
So it can't be the EC2 instance itself, can it? Is there an issue routing websockets via ports in an ALB?
-- Edit --
Current SG of the ALB:
The EC2 instance SG:
Accepted answer here seems to be "open Security Groups for EC2 (web server) and ALB inbound & outbound communication on required ports since websockets need two way communication."
This is incorrect and the reason why it solved the problem is coincidental.
Let me explain:
"Websockets needs two way communication..." - Sure but the TCP sessions is only ever opened from one way - from the client.
You don't have to allow any outbound connections from the EC2 instance (web server) in order to use web sockets.
Of course the ALB needs to be able to do TCP connections to the EC2 instance. But not to the client. Why? Well the ALB is accepting TCP connections (usually on port 80 and 443). It is setting up a TCP session that was initiated by the client. It is then trying to set up a new TCP session to the web server behind the ALB. This should be done on the port that you decided to have the web server listening on. The Security Group around the ALB needs to be able to do outbound connections on this port to the web server. This is the reason why "open up everything" worked. It has nothing to do with "two way communication".
You could use any ports of course but you don't need to use any other ports than 80 & 443 (such as 8080) on both the Load Balancer or the EC2.
Websockets need two way communication, make sure security groups attached to all resources (EC2 & ALB) allow both inbound & outbound communication on required ports.
I have used EB to create an environment with Tomcat 8, Java 8 configured as load balanced, auto scaling.
Deployed a WebSocket server on this.
On the EC2 running instance, my websocket client (tyrus API) is able to communicate over websocket, for example ws://ip/chat
Now I need a TCP connection (count) based auto scaling strategy, for which switched to Application Load Balancer (ALB) with a target group pointing to this EC2 instance.
Stickiness has been enabled and ALB is using HTTP listener on port 80 with listener rule "/chat" pointing to this target group.
All involved SG have All TCP in and out traffic enabled for testing.
Invoking ws://ELB/chat results doesnt work resulting in a 404:
Caused by: org.glassfish.tyrus.core.HandshakeException: Response code was not 101: 404
Any inputs on how this should be configured.
Final aim is to be able to communicate with WebSocket server over ALB and then auto scale based on TCP "ActiveConnectionCount"
I am trying to setup an Elastic load balancer to route requests to a cluster of node.js servers running Primus.io with sockjs to manage real time communications.
I have set up the load balancer to listen with the following configuration:
HTTPS 8084 -> HTTPS 8084 (The port used on my node.js servers)
SSL 443 -> TCP 80
My understanding is that the only way to get websockets to work through ELB is via SSL->TCP, hence the above configuration.
I have correctly enabled the new proxy protocol for ELB as described here:
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/enable-proxy-protocol.html
When trying to connect to the server from a client an HTTPS request is initially sent and then from what I can gather it should be upgraded to websockets. But the request is simply failing when I send it to the loadbalancer address.
If I send the initial Primus connection request to the ip of a single nodejs server like so:
var primus = new Primus('https://ip.address.of.single.server:8084');
The request is correctly returned and is upgraded to websockets correctly.
When I switch the ip address to that of the balancer, it fails and the initial https request to the node.js server returns nothing. I assume this means that the websocket transfer could not be established, but to be honest I have little experience in this area so could be completely wrong.
Does anyone have any idea what I am doing wrong?
Thanks in advance
Do you have clustered your NodeJS-instances? For example, if you use SocketIO you should use a clustered session store. Actually, I'm also currently investigating the same with SockJS running on top of Vertx.
The problem behind is Amazon ELB won't respect any forwards in the past (in opposite to Sticky Session on top of HTTP) which means that a connections via TCP level can be forwarded at any cluster's node. Yes, one tcp channel would be okay. But frameworks like SocketIO do a little bit more to support sessions (does not exist in WebSockets) and multiple transport layers (http, polling, sockets, and so on).
Good Day,
I have been using AWS quite a bit for my cloud based system for a hardware project. Using SimpleDB and the notification service provided is great.
However, I need a backend on AWS that basically listens to requests coming in, processes it and sends it back to a particular address. Some kind of UDP service.
I could easily write a c#/c++ app for it, but i am not sure if I can host it on AWS. Does anyone know how this works?
Short answer: yes.
EC2 instances are just like any other virtual machine, obviously you can put in a server that listens to UDP. Configuring the network for this is, of course, slightly more complicated, but possible. The one thing making it more complicated is that with UDP you will not be able to enjoy the load balancer service that Amazon offers, as it (currently) only supports TCP-based protocols.
So, if you have one server you wish to put on the internet, the procedure is probably same as what you'd do with a TCP server: set up a server and an elastic IP pointing to it, and then have your clients connect to it (by knowing the elastic IP you've been allocated, or by referring to that IP via a DNS resolution). If you have multiple servers you wish to set up, answering the same address, life is a bit more complicated. With TCP, you could have set up an Amazon load balancer and assign your elastic IP to the load balancer. If you'd want a load balancer for UDP, the Amazon stock load balancer can't do that, but you can still find a software load balancer (there are hundreds of them on Amazon's public images library) to set up.
Nginix has an Amazon image that will load balance UDP for $2,500/yr or you can launch your own EC2 instance and use open source Nginx.
My specific use case was for a UDP logging service, if you can use hostnames Route 53 could be a scalable managed solution as well.