Suppose you have a website which is very slow but you don’t know the reason because you have proper hardware and CPU configurations , even you have high speed RAM also. All your code and applications are optimised, still your website is taking high time to load pages. After lot of debugging, you found that website’s TTFB is taking too long. Another reason that you got to know behind this is your DNS resolution time, it is taking longer to convert domain name into the respective IP address. During this entire performance testing process your business is sacrificing because it takes a lot of time to identify the reason behind the slow performance of the website. If you are already aware about the impact of DNS on the website it becomes easy to improve the performance. So it is very important to understand what is domain name system and its role.
DNS stands for Domain Name System, it is an address translator that converts IP addresses into human readable form. Without DNS mapping of IP into readable text, no one would be able to remember random strings of numbers to access a website.
It’s database that stores domain names along with their corresponding IP addresses for a particular domain like .com , .net, .in, etc. Then it identifies the resource and the computer system on internet.
How it works
Whenever a user types a human readable text in the web browser to search for a website, it will search for the information into the local cache. If the requested address in not their local cache, it will look for the DNS server in LAN. And when the requesting server is found, it will return the result.
Here are the few examples :
Improperly Configured DNS records
If you are not setting the correct values and IP addresses for your data, you are likely to be sidetrack by DNS resolution issues.
Hardware failures on the host computer or network failures that may be beyond your control cause DNS problems.
Measure that can be taken to improve website performance
- Do not use low TTL – Shorter the TTL, faster the user machine will have to request again for the domain. By using high TTLs, you ensures that the information stores locally on the user’s computer and also on the DNS ISPs – which affects multiple users.
- Geographical Distribution – If you’re a famous site, make sure you have a location based distributed DNS network or let someone else manage domain name for you.
- Unreliable registrar – If you are planning to build the next page and get + 100 K hits a second .Make sure that your DNS server is able to handle the load or assign your NS records to someone with the capacity / reliability.
- Backup plan – You should have a backup plan. Even if you’re using a big DNS management company, they also have problems.
- Capacity – If you are getting lot of requests , make sure that either you have plenty of capacity on your servers or let someone else manage DNS for you.