Is it possible to use AWS Application Loadbalancer for RSocket?
An AWS Application Loadbalancer can also be used for WebSocket connections and my project uses RSocket with WebSocket as its transport. This made me wonder if it is possible to use this loadbalancer for RSocket aswell.
On one hand I would think it is possible to use this loadbalancer, as it only receives a connection and passes this to the target RSocket server.
On the other hand, if all RSocket frames go through the loadbalancer, it might not know how to handles these frames, which would make it not possible to use.
I couldn't find much about RSocket and loadbalancing online besides this post .But this is client side loadbalancing and I was looking for server side loadbalancing.
And this post .But this uses LoadBalanceSocketClient while I want to find out if an AWS Application Loadbalancer can be used.
Here follows a simple diagram of what I would like to have (if possible):
The RSocket client connects to the loadbalancer which passes the connection to a RSocket server (for example server A). Then the client and RSocket server A can communicate.
AWS will see this as a typical websocket service. So as long as it lets HTTP/1.1 connections through and lets them upgrade to WebSocket there shouldn't be a problem. This is very standard so it shouldn't be an issue. Ideally it won't see individual frames of the traffic, and you app will handle all frames on a single WebSocket connection. But it looks like the API Gateway support does deal with individual messages https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-set-up-websocket-deployment.html. You should ignore the RSocket client load balancing, and focus on AWS WebSocket routing.
As an example, with GCP (instead of AWS) the complexity is that this bumps you up from AppEngine Standard to Flexible. The demo site https://demo.rsocket.io/ is deployed to GCP and exposes websockets.
The additional kink, is that you possibly want stateful routing if you want client resumption.
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I was hoping someone may be able to explain how I would setup a multi-tiered web application. There is a database tier, app tier, web server tier and then the client tier. I'm not exactly sure how to separate the app tier and web server tier since the app tier will be in a private subnet. I would have the client send the request directly to the app server but the private net is a requirement. And having the app server separated from the web server is a requirement as well.
The only idea I have had was to serve the content on the web server and then the client will send all requests to the same web server on another port. Like port 3000, if a request is captured on that port, a node app using express will forward the request to the app tier since the web server can speak to the app server.
I did setup a small proof of concept doing this. The web server serves the content, then I have another express app setup to listen on port 3000, the client sends the request on port 3000 and then it just sends the exact same thing back to the app server.
This is my current setup with the web servers hosting two servers. One to serve the frontend on port 80 and one to receive requests on port 3000. The server listening on port 3000 forwards all requests to the app server ALB(It's basically a copy of all the same routes on the app server but it just forwards the requests instead of performing an action). But is there a way to not have this extra hop in the middle? Get rid of the additional server that is listening on 3000 without exposing the internal ALB?
To separate your web servers and application servers, you can use a VPC with public and private subnets. In fact, this is such a common scenario that Amazon has already provided us with documentation.
As for a "better way to do this," I assume you mean security. Here are some options:
You can (and should) run host based firewalls such as IP tables on your hosts.
AWS also provides a variety of options.
You can use Security Groups, which are statefull firewalls for your hosts
You can also use Network Access Control Lists (ACLs), which are stateless firewalls used to control traffic in and out of subnets.
AWS would also argue that many shops can improve their security posture by using managed services, so that all of the patching and maintenance handled by AWS. For example, static content could be hosted on Amazon S3, with dynamic content provided by microservices leveraging API Gateway. Finally, from a security perspective AWS provides services like Trusted Advisor, which can help you find and fix common security misconfigurations.
i am traying to figure it out how is the best way to deploy a TCP/IP and UDP service on Amazon AWS.
I made a previous research to my question and i can not find anything. I found others protocols like HTTP, MQTT but no TCP or UDP
I need to refactor a GPS Tracking service running right now in AMAZON EC2. The GPS devices sent the position data using udp and tcp protocol. Every time a message is received the server have to respond with an ACKNOWLEDGE message, giving the reception confirmation to the gps device.
The problem i am facing right now and is the motivation to refactor is:
When the traffic increase, the server is not able to catch up all the messages.
I try to solve this issue with load balancer and autoscaling but UDP is not supported.
I was wondering if there is something like Api Gateway, which gave me a tcp or udp endpoint, leave the message on a SQS queue and process with a lambda function.
Thanks in advance!
Your question really doesn't make a lot of sense - you are asking how to run a service without running a server.
If you have reached the limits of a single instance, and you need to grow, look at using the AWS Network Load Balancer with an autoscaled group of EC2 instances. However, this will not support UDP - if you really need that, then you may have to look at 3rd party support in the AWS Marketplace.
Edit: Serverless architectures are designed for http based application, where you send a request and get a response. Since your app is TCP based, and uses persistent connections, most existing serverless implementations simply won't support it. You will need to rewrite your app to support http, or use traditional server based infrastructures that can support persistent connections.
Edit #2: As of Dec. 2018, API gateway supports WebSockets. This probably doesn't help with the original question, but opens up other alternatives if you need to run lambda code behind a long running connection.
If you want to go more Serverless, I think the ECS Container Service has instances that accept TCP and UDP. Also take a look at running Docker Containers with with Kubernetes. I am not sure if they support those protocols, but I believe they do.
If not, some EC2 instances with load balancing can be your best bet.
I'm developing a stocks app and have to keep users browser updated with pricing changes
I don't need to access past data, browser just have to get current data whenever it changes
is it possible to filter a dynamodb stream and expose an endpoint (behind api gateway) that could be used with a javascript EventSource?
I realize this is not using Server Sent Events but AWS just announced Serverless WebSockets for API Gateway. Pricing is based on minutes connected and number of messages sent.
Product Launch Article: https://aws.amazon.com/about-aws/whats-new/2018/12/amazon-api-gateway-launches-support-for-websocket-apis/
Documentation: https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-websocket-api.html
Pricing: https://aws.amazon.com/api-gateway/pricing/
API Gateway is a store-and-forward service. It collects the response from whatever the back-end may happen to be (Lambda, an HTTP server, etc.) and then returns it en block to the browser -- it doesn't stream the response, so it would not be suited for use as an Eventsource.
AWS doesn't currently have a managed service offering that is obviously suited to this use case... you'd need a server (or more than one) on EC2, consuming the data stream and relaying it back to the connected browsers.
Assuming that running EC2 servers is an acceptable option, you then need HTTPS and load balancing. Application Load Balancer supports web sockets, so it also might also support an eventsource. A Classic ELB in TCP (not HTTP) mode should support an eventsource without a problem, though it might not correctly signal to the back-end when the browser connection is lost. Both of those balancers can also offload HTTPS for you. Network Load Balancer would definitely work for balancing an eventsource, but your instances would need to provide the HTTPS, since NLB doesn't offload it for you.
A somewhat unorthodox alternative might actually be AWS IoT, which has built-in websocket support... Not the same as eventsource, of course, but a streaming connection nonetheless... in such an environment, I suppose each browser user could be an addressable "thing."
Does AWS support websockets with SSL ?
Can EWS ELB be used for websockets over SSL ?
What happens when a EC2 instance(machine) is added or removed to this ELB. Especially removed; what if a machine goes down. are the existing sockets routed to some other machine or reseted to connected.
can ELB be a bottleneck at any point in time.
any other alternatives .. let me know
This link might prove partially helpful for you - it would appear that you can do web sockets over SSL, but currently I'm struggling to implement it.
StackOverflow - Websocket with Tomcat 7 on AWS Elastic Beanstalk
Currently AWS ELB doesn't support Websocket balancing, there is a trick to do it via SSL, but it has some limitation and depends on your app logic. So if websocket connection is used only as server-client communication, it will work. But if you have more advanced logic when clients must communicate with each other via a server then this solution won't work. For example one client has established connection for a chatroom, then other clients can connect to the established chatroom and communicate with each other.
Then only possible way to use HA-proxy http://blog.haproxy.com/2012/11/07/websockets-load-balancing-with-haproxy/
But shown example just shows how to configure HA-proxy base on two servers. So if you do not use Amazon Autoscalling Group, the solution is good. But if you will need use ASG, the question about add/remove instances to ha-proxy config is other challenge.
I am trying to turn the server/client model into a server/server model, so as to have the my 2 computers running the program find each other by perhaps a url or something else like ip address.I was wondering if it was possible for 2 servers to connect via url's. or is ip the only way? examples would be appreciated since this is my second day writing c++.
For HTTP, the server only talks to clients. So, I am not sure what you mean by server to server.
URLs are fine to use to access an HTTP server, but the host name will need to be resolved into an IP address before a network connection can actually be established. You should be able to find libraries that will do those details for you, but it is not hard to manually establish a socket connection to an HTTP server.
There are configurations where there are multiple servers, acting as a single server. These are sometimes referred to as web farms or a HTTP cluster. Typically, there is some sort of load balancer in front of the cluster. Many HTTP load balancers support a server affinity feature to make sure a client is sent to the same server in the cluster for subsequent operations.
In a cluster configuration, servers may need to synchronize shared state, such as file system data or configuration data. This is typically handled by some mechanism that is external to the HTTP server process itself. The HTTP server process may need to cooperate with the synchronization, but this can be as simple as restarting the process.
There is another mode of HTTP server configuration called a reverse proxy configuration. A cluster of HTTP proxy servers sit in front of a single HTTP server. The proxy servers are thought to be cheap and expendable entities that off load work from the HTTP server itself, providing a scalable means to increase HTTP server capacity.
There are many open source HTTP server and proxy projects available as examples of how they are implemented. If you are trying to build your own custom server application, you can have a look at the HTTP examples in Boost asio.