For our SaaS app, we're allowing customers to point their domain name to our server.
The plan right now is to simply hand out one of our AWS elastic IP addresses for them to point their domain to. The elastic IP address would essentially be pointed to a EC2 instance web-server...and maybe a load balancer in time (if traffic demands it!).
The user would specify what their domain is in our app, and we'd be able to resolve the host name coming in as their app.
My concern is the longevity of this solution. This IP cannot change. And we'll certainly be tied to AWS if we go this route.
(Note: Being a 1-2 person startup, standing up a data-center is more than likely no-go, and we hope to use AWS or Azure).
What solutions would make this IP address -> SaaS Web Server concept last in the long run, with flexibility, and as minor of a tie as possible to a cloud provider?
With running the risk of asking "what is the best way to do this"...what's the best way to do this, keeping in mind longevity and small opt-in to a cloud provider?
You can't point an IP address to a load balancer, so this seems like a very bad idea. You need your own domain/subdomain that clients can point their domains/subdomains to via a CNAME record on their end. Then if the location of your service ever changes you just have to update your domain record and their DNS records will continue to be correct.
Related
I am a bit new to the deployment of a website. I have a server which is written in Node.js. Previously I had been using Heroku for deploying my apps without knowing much about deployment. I would like to know how do I deploy my server to create a website which has .com at the end of it like www.example.com and not www.example.herokuapp.com. I think it has something to do with domains (correct me if I am wrong). I would like to know what exactly is a domain and a DNS provider and how to deploy a website in such a way. Thank you.
You should ask one question to yourself when you hit www.example.com in browser how does it load a page?. When you run a website on your laptop it basically runs locally, if you want to access your website over the internet you would require public IP(host or server) accessible over the internet so you can access a webpage using public IP:port. But this is not the best option because IP may change in the future and also remembering IP for each application will be difficult. Imagine if you access Facebook, Instagram or any other websites by its IP addresses how difficult and inconvenient would it be? There are a couple of things you should know.
DNS-> Domain Name system
Every host is identified by the IP address but remembering numbers is
very difficult for the people and also the IP addresses are not static
therefore, a mapping is required to change the domain name to IP
address. So DNS is used to convert the domain name of the websites to
their numerical IP address.
DNS is a hostname to IP address translation service. DNS is a distributed database implemented in a hierarchy of name servers. It is an application layer protocol for message exchange between clients and servers.
Name servers
Domain Name Servers (DNS) are the Internet's equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.
DNS record
A domain name, IP address what is the validity?? what is the time to live ?? and all the information related to that domain name.
Once you understand the DNS
Host(Deploy) your website to Amazon EC2 or Heroku and obtain Public IP.
Buy a domain from domain provider like Godaddy
Map domain(ie www.example.com to IP)-> DNS record
Mapping domain to IP may vary platform to platform but the Core principle remains the same. I would suggest you these below link. Try to find differences in both, doing so you will learn along the way
http://www.littlebigextra.com/map-domain-name-amazon-aws-ec2-instance/
https://medium.com/progress-on-ios-development/connecting-an-ec2-instance-with-a-godaddy-domain-e74ff190c233
In the world of microservices endpoints should not (must not) be hardcoded. One of the best ways to do this is to have a DNS and let each microservice register while starting. By doing this whenever microservice A wants to communicate with microservice B it just asks DNS for endpoints where B currently listens.
What I do not understand is: How microservices know where the DNS lives?
Basically DNS is just a 'special' service and I can have one or multiple instances of it right? So I should not hardcode it's endpoint too or should I? And let's say I do - what if DNS instnace is moved to different location? Do I have to manually change it's location in configuration?
Does anyone happen to know how to design this? (or can anyone just point me to any document where this is explained since although there are many information about microservices and dns I can not find this particular information anywhere - maybe it's just too trivial and I am the only one who does not get it)
Manual setup of DNS is possible, as stated by the other answers, but I would recommend to use an infrastructure that supports the service discovery in all respects. For example kubernetes has built in DNS support and makes it very easy to expose a service that can consist of any number of Pods.
An infrastructure technology like kubernetes will also make many other respects of the microservices architectural style easier to implement, including high availability and scalability.
Please see the official docs for some more information.
DHCP solves this problem. When a host boots it sends a broadcast DHCP message. The DHCP server responds with many values, one of which is the location of DNS servers.
In the case of micro services, the host OS (or container host) will be configured for DNS via DHCP. The microservice code uses the OS DNS functions to resolve addresses.
https://en.m.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
You can use your local network to discover services, via Dhcp and whatnot. But that requires that all services are already "registered" within that DNS server.
Microservices can find each other via service discovery, server or client side. If you choose client side service discovery, you can use tools like Consul, which provides a bunch of great features. One of which is a DNS endpoint which allows queries via SRV records with <serviceName>.consul.service domain names.
Consul has it's own DNS endpoint, you can configure your services to use that (usually on port 8600 locally, as Consul agents run locally).
But you can also configure an actual DNS server to forward questions to Consul, so that you can easily mix service discovery drive by Consul with manually setup services within a Bind instance or similar...
Known hostname solution. The fixed part would be the service domain name, for instance xservice.com. You can query this host using standard DNS tools (e.g., dig in your shell, etc).
Finally, in the DNS bound to xservice.com you then add a SRV record with further details.
A SRV record lists all the service details, including:
the symbolic service name;
the canonical hostname of the machine providing the service;
the TCP (or UDP) port on which the service is available.
There are many other info as well. Please see Wikipedia for the complete list.
Please keep in mind this is a somewhat static solution. If you are looking for a more dynamic one, then Oswin answer might be a better fit :-)
I have a webapplication in multiple Regions in the Azure Cloud and i'm using the Traffic Manager in Performance mode zu redirect the user to the closest Region.
What's concerning me is the following:
With this site https://www.whatsmydns.net i checked my Webapplication to see, which Datacenter is selected.
The funny thing is, that people from California gets redirected to the server in Westeurope but there is a Server in US Central too.
So from the site of the traffic manager the ping to the europe server is faster then to US central.
But i believe, that the difference between these too can not be high...
Now i have the fear, that it can happen that a user jumps between US Central and Europe all the time because he is in such a zone where the latencies to the available servers are nearly identical.
I also store files in a Azure Storage account in each region. If the user now jumps, i would have to transfer these files between the regions all the time...
So i was wondering if there is a possibility to redirect the user by his GEOIp to a specific region than by latency?
One of the benefit of the traffic manager is in my eyes that i can use one domain for all regions...
the only solution for my problem i can think of is a own cloudservice which replaces the traffic manager and redirects the user to the different regions by their IP like us-center.DOMAIN.com, we-eu.DOMAIN.com etc...
Are there any other solutions?
Thanks for your help!
Br,
metabolic
If you believe Traffic Manager is routing queries incorrectly, that should be raised with Azure Support.
Traffic Manager 'Performance' mode routing is based on an internal 'IP address to Azure data center latency map. The source IP of the DNS query (which is typically the IP of your DNS server) is looked up in the map to determine which Azure location will offer the best performance. There is an implicit assumption that the IP address of the DNS server is a good proxy for the location of the end user.
The 'Performance' mode in Azure Traffic Manager is deterministic. Identical queries from the same address will be routed consistently. The only exception is that routing may change during occasional map updates, which affect only a small %age of the IP address space.
A more common cause of routing changes is customers moving from place to place. For example, during travel, or simply by picking up a Wifi network that uses a DNS service in a different location, with a different IP address.
A Geo-IP based routing is not currently supported by Traffic Manager. However, please note that it would work in the same way as the 'performance' routing, just that it would use a different map. Users could still be routed to different locations as a result of map updates or changing DNS servers.
As you describe, if your application requires a strong, un-violable association between a user and a region, one option is re-direct users at the application level (e.g. via HTTP 302).
I am starting to develop a webservice that will be hosted in the cloud but needs higher availability than typical cloud SLAs provide.
Typical SLAs, e.g. Windows Azure, promise an availability of 99.9%, i.e. up to 43min downtime per month. I am looking for an order of magnitude better availability (<5min down time per month). While I can configure several load balanced database back-ends to resolve that part of the issue I see a bottleneck at the webserver. If the webserver fails, the whole service is unavailable to the customer. What are the options of reducing that risk without introducing another possible single point of failure? I see the following solutions and drawbacks to each:
SRV-record:
I duplicate the whole infrastructure (and take care that the databases are in sync) and add additional SRV records for the domain so that the user tying to access www.example.com will automatically get forwarded to example.cloud1.com or if that one is offline to example.cloud2.com. Googling around it seems that SRV records are not supported by any major browser, is that true?
second A-record:
Add an additional A-record as alternatives. Drawbacks:
a) at my hosting provider I do not see any possibility to add a second A-record but just one... is that normal?
b)if one server of two servers are down I am not sure if the user gets automatically re-directed to the other one or 50% of all users get a 404 or some other error
Any clues for a best-practice would be appreciated
Cheers,
Sebastian
The availability of the instance i.e. SLA when specified by the Cloud Provider means the "Instance's Health is server running in the context of Hypervisor or Fabric Controller". With that said, you need to take an effort and ensure the instance is not failing because of your app / OS / or pretty much anything running inside the instance. There are few things which devops tend to miss and that kind of hit back hard like for instance - forgetting to configure the OS Updates and Patches.
The fundamental axiom with the availability is the redundancy. More redundant your application / infrastructure is more availabile is your app.
I recommend your to look into the Azure Traffic Manager and then re-work on your architecture. You need not worry about the SRV record or A-Record. Just a CNAME for the traffic manager would do the trick.
The idea of traffic manager is simple, you can tell the traffic
manager to stand after the domain name ( domain name resolution of the
app ) then the traffic manager decides where to send the request on
considerations of factors like Round-Robin, Disaster Management etc.
With the combination of the Traffic Manager and multi-region infrastructure setup; you will march towards the high availability goal.
Links
Azure Traffic Manager Overview
Cloud Power: How to scale Azure Websites globally with Traffic Manager
Maybe You should configure a corosync cluster with DRBD ?
DRBD will ensure You that the data on both nodes are replicated (for example website files and db files).
Apache as web server will be available under a virtual IP to which domain is pointed. In case of one server is down corosync will move all services to second server within few seconds.
I have two servers that provide a service to clients.
The client devices access the server through a DNS name. example.com
Now we generally use server1 (primary) but if server one becomes inaccessible, I want the DNS to change its resolving name to server 2 (secondary server)
How can I go about doing this, Is there a service that dyndns provides?
The only way I know to do it is to log into the DNS server and manually change the addresses that the dns resolves 2.
It sounds like you're looking to create an automated failover in the event of an outage. While this is a service that Dyn provides as an added service in the DynECT Managed DNS service (hit up sales#dyn.com for more info on that), you can also use the Dyn Updater API to push an IP update up to your Standard DNS account as well. It would be a matter of using a 3rd party monitoring solution to trigger the update in your code using their API, then using the Dyn Updater API to switch the IP.
http://dyn.com/support/developers/api/
Whether you want to spend the money on upgrading to DynECT Managed DNS or keep using your Standard DNS account, we can help you either way.
Good luck, and if you have any other questions, please do not hesitate to ask.
CL