The 502 Bad Gateway error is a type of HTTP status code that means when you try to connect a web page, but one web server gets an invalid response from another web server called a 502 error because the HTTP status code that the web server uses to describe that is a kind of error.
The Bad Gateway 502 can be customized by every website. Different web servers do describe this error in different manners. According to your web server, you might see a different bad gateway 502 error.
502 Bad Gateway
502 Service Temporarily Overloaded
Temporary Error (502)
502 Proxy Error
502 Server Error: The server encountered a temporary error and could not complete your request
502. That's an error
Bad Gateway: The proxy server received an invalid response from an upstream server
HTTP Error 502 - Bad Gateway
“502 Service Temporarily Overloaded”
“502 Bad Gateway NGINX”
The "fail whale" most famous Twitter error that says Twitter is over capacity is really a 502 Bad Gateway error. Even though here 503 Error would make more sense.
A 502 error when received in Windows Update it generates a 0x80244021 error code or the message WU_E_PT_HTTP_STATUS_BAD_GATEWAY.
These 502 bad gateway error responses could be appear due to a number of different causes. It is possible the server is overloaded or network issues between the two servers, and it is just a temporary problem. It is also possible there is an incorrectly configured firewall or even a coding error, and all that problems won't get fixed until those issues are addressed.
Causes of a Bad Gateway 502 error are given below:
The bad gateway 502 may appear if a website's server can crash due to its operational memory capacity has exceeded and has overloaded, which is normally related with an unanticipatedly high number of visitors trying to connect to the site - such as a DDoS(Distributed Denial of Service) attack.
You can resolve the server overloaded issue by controlling network traffic, by using Firewalls to block unwished traffic coming from poor IP sources, by expanding web cache methods. This cache method saves a lot of time and by implementing different domain names to subserve different contents by separating the web servers.
Look for server connectivity issues:
Most of the websites live on multiple servers or third-party hosting providers. If your website's server is down for maintenance or any other reason, your website show the visitors a 502 Bad Gateway Error page.
The only way to fixed this issue is to wait for your server to finish maintenance or fix the problem causing the error.
one quick way for checking is your messages are reaching your IP or not, you may be running a ping test.
Your firewall just like your website's gatekeeper. It's protecting your site from spiteful visitors or DDOS(Distributed Denial of Service) attacks.
Sometimes, a faulty firewall configuration may block the communication between the edge servers and the origin server. This can also be caused due to security plugins of your CMS(Content Management System). Some DDOS(Distributed Denial of Service) protection systems can over-react and start blocking requests from our content delivery servers.
Check your firewall configuration to pinpoint and fix the issue.
Origin server down:
The server is not accessible, either it is down or there is no connectivity to the server given.
Sometimes an error in a website’s code means that requests cannot be answered correctly, indicates this error to expose.
Check your code to find errors or copy your code into a development machine. It will perform an exhaustive debug process that will simulate the situation that your 502 bad gateway cloudflare Error occurred in and allow you to see the exact instant where things went wrong.
Routing problems, DNS issues and ISP related issues can also cause a Bad Gateway 502.
This error can also arise when a web server takes more time to complete and a caching tool reaches its timeout values that time. This problem is also appearing due to Slow queries.
Domain name not resolvable:
The domain name is not appointed to the correct IP or it does not resolve to any other IP. It is most important to note that DNS changes could take same time until they are global fully propagated and active. This is dependent on the TTL(Time-to-live), or time to live, defined per record.
Check for any DNS changes:
If you are recently changed host servers or moved your website to a different IP address, it will make changes to your website's DNS server. This cause will show to the visitors a 502 Bad Gateway nginx error page.
Your website will not be up and running until these DNS changes take full outcome, which can take a few hours.
Sometimes browser extensions can also cause errors with the display of a website and generate a 502 error.
Server logs will provide you the details about your server's health and status. Sift through server logs to uncover and respond to any alarming information.
If you can't find out the problem on your own end, or if you think your host company is responsible for this, give them a call. They may be able to look deeper into the bad gateway 502 to what's going on and shed some light on the situation.
If the issue is on their end, they might be able to easily fix it. If the problem is related specifically to your website, they might also be able to walk you through the solution.
It is possible, something may be wrong on your end, here are some solutions for this fixing:
Reload the page:
Sometimes server connectivity issues are temporarily and it resolved relatively quickly. Before you dive deep into the problem, take steps to insure that this is actually a major error.
Wait one or two minute. Then reload the page. If the page loads with no error, this might be a temporary connection problem.
If the page is still giving you an error then try to loading the URL again by pressing F5 or Ctrl+R on your keyboard, or by clicking the refresh/reload button.
Clearing the browser cache:
It's possible that the 502 error you received was due to an issue on your computer that occurred sometime during this use of your browser. Outdated or corrupted files that are being stored on your browser could be causing 502 Bad Gateway issues.
In simple start a new browser session by closing all open browser windows and then opening a new one and Then try to opening the web page again.
Hard-refreshing On Macs is done by pressing Cmd + Shift + R.
Clearing the Cache in chrome
Press Ctrl + Shift + Delete.
A new window will display to clear the browsing data. Ensure that the boxes are checked.
Click on the “Clear browsing data” button.
Clearing the Cache in Mozilla Firefox.
Press Ctrl + Shift + Delete.
You will get a window display regarding clear recent history. Ensure that the boxes are checked.
Click on the “Clear Now” button.
Delete your browser's cookies:
browser's cookies may be the reason of 502 errors.
If you had not clear all of your cookies, you could first be removing only those cookies related to the site who give the 502 error. It's best to remove them all but firstly clear the site's cookies.
To delete cookies in Chrome.
Go to the Chrome menu icon and click 'Settings'
Click "Show advanced settings" at the bottom.
In the "Privacy" section, click "Content settings" button.
In the "Cookies" section, Click "All cookies and site data"
To Delete all cookies, click "Remove all" button.
To delete cookies for any single website in Mozilla Firefox:
Click the menu button and choose Options.
Select the Privacy & Security panel and go to the Cookies and Site Data section.
Click on the "Manage Data" button.
In the Search websites field, type the name of the website whose cookies you want to remove.
Click Save Changes.
Restart your computer/networking equipment:
Restart your networking equipment because issues with your router, modem, switches, or other networking devices could be causing Bad Gateway 502 or other 502 errors. A simple restart of these devices could help or change your DNS servers, on your router or on your computer or device.
Some temporary issues with your computer could be causing 502 bad gateway error, specially if you are seeing the error on more than one website. In these cases, a restart would help.
Start your browser in Safe Mode:
Running your browser in Safe Mode which means to run it with default settings and without add-ons or extensions, including toolbars.
If the bad gateway 502 no longer appears when running your browser in Safe Mode, it's mean that some browser extension or setting is the cause of the problem. Revert your browser settings to default and selectively disable browser extensions to find the root cause and permanently fix the problem.
You do not need to start Windows in Safe Mode to run any browser in its particular "Safe Mode."
Try another browser:
you can check the site in popular browsers include Firefox, Chrome, Opera, Internet Explorer, and Safari, among others.
If the other browser doesn't produce a Bad Gateway 502, that's means your original browser is the source of the problem. So now you reinstall your browser and see if that corrects the problem.
Contact your ISP:
If you think that a website is down for everyone, specially a popular one. The best way for checking site is down to search for #websitedown on Twitter, as in #cnndown or #instagramdown. There are some other ways to see if a website is down if social media isn't helpful.
If your browser, computer, and network are all working properly and the website reports that the page or site is working for them, the 502 Bad Gateway nginx issue could be caused by a network issue that your ISP is responsible for. Contact your Internet Service Provider.