I have a website that is growing so my dedicated server can't handle and the lag is real deal. So I decided to try cloud hosting and for this purpose I will use nginx as load balancer.
Qustion 1.
If I configure the main webserver where domain.tld is located as load balancer like the example here will I be able to use the same server for all my other domains(right now I use normal nginx config to maintan 10 small websites on the same webserver), or the main role will be ONLY to balance and redirect the traffic.
Question 2.
Shall I put copy of the files on the mirror servers ?
Example : my website is in the http_web folder , where he communicate with MYSQL server. How the requests are handled ? What happens when the balance server redirect the client to the server1 ?
Question 3.
I plan to start with this structure:
Load balancer (dedicated server) + Mysql -> http servers1, server2,,, on demand3..4..5.. Is that ok?
This diagram should help with how you should set it up. Forgive me if I missed your point to your question. So the green is what is public and red is your private internal network. So your load balancer which you want as nginx has two networks connected to it. Your external public network and your internal network. The lb should handle all the ip's coming from your clients. Then nginx delegates the client to one of the webapps through the private internal network. I hope this helps.
Related
Im' looking to build a similar application to https://www.proxysite.com/ but am not sure on the best architecture.
Looking to have a data flow like this.
User Web Browser -> myproxysite.com -> Ngninx Proxy Server (somehow rotating IP for each client session) -> Targetsite.com
Then the user would need to maintain a full session on Targetsite.com as a logged in user.
In this example, targetsite.com is always the same site and is pre-determined. The challenge we are facing is that targetsite.com is blocking our users based on IP, many of whom are accessing it from the same office network.
So my questions are:
Does this seem correct?
Is there anyway for me to configure nginx with a rotating proxy service like luminati? Or do I need to add an API software layer to handle the actual IP changes?
Any guidance on this one would be greatly appreciated!
While I can't help you with your application, I do want to suggest an alternative. You mentioned an office so it sounds like the users who will use the proxy are workers.
Luminati (now BrightData) has a proxy manager which you can host on any server. The proxy manager allows you to create ports (ie port 24000) and configure it with whatever proxy you want (doesn't have to be BrightData's proxy). It has a ton of different parameters that you can include for each proxy (including IP rotation) and each port can be configured to have a unique setup.
Then you simply go to your user PC, open the browser proxy settings, type the IP address of the server that the proxy manager is running on and the specific port you configured and voila. You have central control of the managing the proxies and your user's browser is proxied.
A big benefit of this is the logs in the proxy manager show all activity on each port you setup, so you can monitor traffic and the success rates right there.
Proxy manager: https://prnt.sc/13uyjgj
I have different versions of a backend service, and would like nginx to be like a "traffic cop", sending users ONLY to the currently online live backend service. Is there a simple way to do this without changing the nginx config each time I want to redirect users to a different backend service?
In this example, I want to shut down the live backend service and direct users to the test backend service. Then, vice-versa. I'm calling it a logical "traffic cop" which knows which backend service to direct users to.
I don't think adding all backend services to the proxy_pass using upstream load balancing will work. I think load balancing would not give me what I'm looking for.
I also do not want user root to update the /etc/hosts file on the machine, because of security and collision concerns with multiple programs editing /etc/hosts simultaneously.
I'm thinking of doing proxy_pass http://live-backend.localhost in nginx and using a local DNS server to manage the internal IP for live-backend-localhost which I can change (re-point to another backend IP) at any time. However, would nginx actually query the DNS server on every request, or does it resolve once then cache the IP forever?
Am I over-thinking this? Is there an easy way to do this within nginx?
You can use the backup parameter to the server directive so that the test server will only be used when the live one is down.
NGINX queries DNS on startup and caches it, so you'd still have to reload it to update.
I am new to Nginx. And I have trobule with it. We have many projects with different language and framework. And they are put in different server. How do I keep the session for every project respectively?
Question is not quite clear but from what i understood i will try to guide you a bit...
Nginx is a web server which when used as reverse proxy basically just sits in front of your project appserver. When some client tries to connect to your appserver, it will first connect to nginx and then nginx will forward that request to you appserver.
eg.
client -Req-> nginx (port 8080) -Req-> appserver(jetty, port 9000)
Now if you are trying to use a single nginx instance and direct request to multiple app servers from nginx. You will either have to make nginx listen on different ports and forward them to different appservers. Or nginx can identify which request is meant for which appserver by routes.
Here is a source which can help you to learn how to configure Nginx to do this... please ask again if you need further help.
https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-server-blocks-virtual-hosts-on-ubuntu-14-04-lts
I've found at that Instagram share their technology implementation with other developers trough their blog. They've some great solutions for the problems they run into. One of those solutions they've is an Elastic Load Balancer on Amazon with 3 nginx instances behind it. What is the task of those nginx servers? And what is the task of the Elastic Load balancers, and what is the relation between them?
Disclaimer: I am no expert on this in any way and am in the process of learning about AWS ecosystem myself.
The ELB (Elastic load balancer) has no functionality on its own except receiving the requests and routing it to the right server. The servers can run Nginx, IIS, Apache, lighthttpd, you name it.
I will give you a real use case.
I had one Nginx server running one WordPress blog. This server was, like I said, powered by Nginx serving static content and "upstreaming" .php requests to phpfpm running on the same server. Everything was going fine until one day. This blog was featured on a tv show. I had a ton of users and the server could not keep up with that much traffic.
My first reaction would be to just use the AMI (Amazon machine image) to spin up a copy of my server on a more powerful instance like m1.heavy. The problem was I knew I would have traffic increasing over time over the next couple of days. Soon I would have to spin an even more powerful machine, which would mean more downtime and trouble.
Instead, I launched an ELB (elastic load balancer) and updated my DNS to point website traffic to the ELB instead of directly to the server. The user doesn’t know server IP or anything, he only sees the ELB, everything else goes on inside amazon’s cloud.
The ELB decides to which server the traffic goes. You can have ELB and only one server on at the time (if your traffic is low at the moment), or hundreds. Servers can be created and added to the server array (server group) at any time, or you can configure auto scaling to spawn new servers and add them to the ELB Server group using amazon command line, all automatically.
Amazon cloud watch (another product and important part of the AWS ecosystem) is always watching your server’s health and decides to which server it will route that user. It also knows when all the servers are becoming too loaded and is the agent that gives the order to spawn another server (using your AMI). When the servers are not under heavy load anymore they are automatically destroyed (or stopped, I don’t recall).
This way I was able to serve all users at all times, and when the load was light, I would have ELB and only one Nginx server. When the load was high I would let it decide how many servers I need (according to server load). Minimal downtime. Of course, you can set limits to how many servers you can afford at the same time and stuff like that so you don’t get billed over what you can pay.
You see, Instagram guys said the following - "we used to run 2 Nginx machines and DNS Round-Robin between them". This is inefficient IMO compared to ELB. DNS Round Robin is DNS routing each request to a different server. So first goes to server one, second goes to server two and on and on.
ELB actually watches the servers' HEALTH (CPU usage, network usage) and decides which server traffic goes based on that. Do you see the difference?
And they say: "The downside of this approach is the time it takes for DNS to update in case one of the machines needs to get decommissioned."
DNS Round robin is a form of a load balancer. But if one server goes kaput and you need to update DNS to remove this server from the server group, you will have downtime (DNS takes time to update to the whole world). Some users will get routed to this bad server. With ELB this is automatic - if the server is in bad health it does not receive any more traffic - unless of course the whole group of servers is in bad health and you do not have any kind of auto-scaling setup.
And now the guys at Instagram: "Recently, we moved to using Amazon’s Elastic Load Balancer, with 3 NGINX instances behind it that can be swapped in and out (and are automatically taken out of rotation if they fail a health check).".
The scenario I illustrated is fictional. It is actually more complex than that but nothing that cannot be solved. For instance, if users upload pictures to your application, how can you keep consistency between all the machines on the server group? You would need to store the images on an external service like Amazon s3. On another post on Instagram engineering – “The photos themselves go straight to Amazon S3, which currently stores several terabytes of photo data for us.”. If they have 3 Nginx servers on the load balancer and all servers serve HTML pages on which the links for images point to S3, you will have no problem. If the image is stored locally on the instance – no way to do it.
All servers on the ELB would also need an external database. For that amazon has RDS – All machines can point to the same database and data consistency would be guaranteed.
On the image above, you can see an RDS "Read replica" - that is RDS way of load balancing. I don't know much about that at this time, sorry.
Try and read this: http://awsadvent.tumblr.com/post/38043683444/using-elb-and-auto-scaling
Can you please point the blog entry out?
Load balancers balance load. They monitor the Web servers health (response time etc) and distribute the load between the Web servers. On more complex implementations it is possible to have new servers spawn automatically if there is a traffic spike. Of course you need to make sure there is a consistency between the servers. THEY CAN share the same databases for instance.
So I believe the load balancer gets hit and decides to which server it will route the traffic according to server health.
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Nginx is a Web server that is extremely good at serving a lot of static content for simultaneous users.
Requests for dynamic pages can be offloaded to a different server using cgi. Or the same servers that run nginx can also run phpfpm.
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A lot of possibilities. I am on my cell phone right now. tomorrow I can write a little more.
Best regards.
I am aware that I am late to the party, but I think the use of NGINX instances behind ELB in Istagram blogpost is to provide high available load balancer as described here.
NGINX instances do not seem to be used as web servers in the blogpost.
For that role they mention:
Next up comes the application servers that handle our requests. We run Djangoon Amazon High-CPU Extra-Large machines
So ELB is used just as a replacement for their older solution with DNS Round-Robin between NGINX instances that was not providing high availability.
Here is our current infrastructure:
2 web servers behind a shared load balancer
dns is pointing to the load balancer
web app is done in asp.net, with wcf services
My question is how to set up the SSL certificate to support https connection.
Here are 2 ideas that I have:
SSL certificate terminates at the load balancer. secure/unsecure communication behind the load balancer will be forwarded to 2 different ports.
pro: only need 1 certificate as I scale horizontally
cons: I have to check secure or not secure by checking which port the request is
coming from. doesn't quite feel right to me
WCF by design will not work when IIS is binded 2 different ports
(according to this)
SSL certificate terminates on each of the server?
cons: need to add more certificates to scale horizontally
thanks
Definitely terminate SSL at the load balancer!!! Anything behind that should NOT be visible outside. Why wouldn't two ports for secure/insecure work just fine?
You don't actually need more certificates at all. Because the externally seen FQDN is the same you use the same certificate on each machine.
This means that WCF (if you're using it) will work. WCF with the SSL terminating on the external load balancer is painful if you're signing/encrypting at a message level rather than a transport level.
You don't need two ports, most likely. Just have the SSL virtual server on the load balancer add an HTTP header to the request and check for that. It's what we do with our Zeus ZXTM 5.1.
You don't have to get a cert for every site there are such things as wildcard certs. But it would have to be installed on every server. (assuming you are using subdomains, if not then you can reuse the same cert across machines)
But I would probably put the cert on the load balancer if not just for the sake of easy configuration.