Webhook comes handy while connecting different applications.

However, it often shows up Webhook 502 error when there is a problem in getting a webserver response.

Such errors can be tricky and web developers may even think of giving up.

At Bobcares, we get requests to solve 502 errors as part of our Server Management Services.

Today, let’s analyze the cause for Webhook errors and see how our Support Team fix it for our customers.

What is a webhook?

Firstly, let’s learn more about webhook as such.

Webhooks are calls from one server to another. To clarify, on some specific events, it will trigger a call.
For example, say we have two domains abc.com and xyz.com. Meanwhile, if you signup on abc.com, it will send a request to xyz.com. Site xyz.com may use the call to send an email or something like that.

For instance, payment solutions like Stripe have a webhook that will automatically send an email to a customer whenever a payment fails to go through.

Cause and Fix for webhook 502 error

Now let’s check on the causes and fixes for 502 errors while using Webhooks.

There are multiple reasons for 502 error while using webhook. But it is a bit tricky to debug as it may or may not have proper logs. Depending on the webhook application you are using, the logs will almost look like the below image.

Let’s check the reasons in detail.

1. Network Error

Our team initially starts checking whether the domain is resolving or not. In other words, if we see an error like “failed to resolve” then we check the DNS.

In many cases, due to recent changes in DNS, the domain may not resolve to the proper IP address. As a result, this kind of error will appear.

Solution: As a temporary workaround, we suggest our clients to replace the domain name with the IP address in the webhook application. Additionally, we also suggest fixes to make the domain resolve to the correct IP.

2. File permission

The error itself says it’s a server-side issue. So we can directly look into the server instead of going through client-side codes. In such cases, we ask for more info from the client. If it stopped working after recent changes then probably the file permission will be the culprit.

Solution: We look for recently changed files and fix permissions or we restore from backups.

3. Firewall settings cause Webhook 502 error

The server Firewall directly affects the connection to and from the server. By default, firewall configuration allows only trusted IP address. And, it may block the request from unknown IP addresses. It can be the server or even the router firewall.

Solution: Here, our Dedicated Engineers debug and fix the firewall rules that block the request. This solves the connection error between the applications.

4. Server connectivity issue – webhook 502 error

It is entirely possible that the server may not be responding. As a result, the webhook returns 502 error.
A server can crash because of exhausting memory or a DDOS attack. Therefore it will return the webhook 502 error.

Solution: Our team mitigates the DDOS attack by taking necessary precautions such as installing mod_evasive. This essentially fixes the server and bring the application back online.

5. Faulty programming

Sometimes destination server receives the request but fails to respond due to faulty code. Hence, webhook respond with a 502 error.

Solution: We usually fix simple codes or give a recommendation to the app developers regarding the probable error causes. This helps the web developers to fix the code errors.

[Need assistance to fix webhook errors? We’ll help you.]

Conclusion

In short, the webhook 502 error happens when there is a failure in getting a response from the server. Today, we saw how our Support Engineers fix errors related to webhook.