Feature Request: Make Healthcheck Actually Do A Healthcheck

Apr 25, 2025 by ADMIN 60 views

Introduction

In the world of containerized applications, healthchecks play a crucial role in ensuring the smooth operation of services. A healthcheck is a mechanism that periodically checks the status of a service, allowing it to automatically restart or take corrective action when it fails. However, in some cases, the healthcheck may not accurately reflect the service's status, leading to potential issues. In this article, we'll explore a feature request to make the healthcheck in a specific application actually do a healthcheck, rather than just returning a 200 status code.

The Current State of Healthchecks

In the application we're discussing, the healthcheck is implemented as a separate endpoint, /thc. When this endpoint is called, it returns a 200 status code, indicating that the service is healthy. However, as the error message suggests, this may not always be the case.

Error while communicating with Invidious companion: Error while communicating with Invidious companion: status code: 500 and body: "Internal Server Error"

Even when the companion fails with an internal server error, the /thc endpoint still returns a 200 status code. This can lead to issues, such as:

False positives: The service may appear healthy when it's not, leading to potential problems downstream.
Delayed detection: The service may not be restarted or taken offline until it's too late, causing further issues.

The Need for a Real Healthcheck

To address these issues, we need a healthcheck that actually checks the service's status. This can be achieved by implementing a more robust healthcheck mechanism that verifies the service's functionality, rather than just returning a 200 status code.

Proposed Solution

One possible solution is to modify the healthcheck endpoint to perform a real healthcheck, rather than just returning a 200 status code. This can be achieved by:

Verifying companion status: The healthcheck can verify the status of the companion service, ensuring that it's functioning correctly.
Checking video fetching: The healthcheck can also check if the companion can fetch videos, providing a more accurate indication of the service's status.

Benefits of a Real Healthcheck

Implementing a real healthcheck has several benefits, including:

Improved accuracy: The healthcheck will provide a more accurate indication of the service's status, reducing the risk of false positives.
Early detection: The healthcheck will detect issues earlier, allowing for prompt action to be taken to resolve the problem.
Reduced downtime: By automatically restarting the service when it fails, the healthcheck can reduce downtime and improve overall system reliability.

Implementation Details

To implement a real healthcheck, the following steps can be taken:

Modify the healthcheck endpoint: Update the /thc endpoint to perform a real healthcheck, verifying the companion's status and checking video fetching.
Implement companion status verification: Add code to verify the companion's status, ensuring that it's functioning correctly.
Add video fetching check: Implement a check to verify that the companion can fetch videos, providing a more accurate indication of the service's status.

Conclusion

In conclusion, implementing a real healthcheck is essential for ensuring the smooth operation of services. By modifying the healthcheck endpoint to perform a real healthcheck, we can improve accuracy, detect issues earlier, and reduce downtime. By following the proposed solution and implementation details, we can create a more robust healthcheck mechanism that provides a more accurate indication of the service's status.

Future Work

Future work can focus on:

Expanding the healthcheck: Expand the healthcheck to verify other aspects of the service, such as database connectivity or API availability.
Implementing automated restart: Implement automated restart of the service when it fails, reducing downtime and improving overall system reliability.

Introduction

In our previous article, we discussed the importance of implementing a real healthcheck in a specific application. A healthcheck is a mechanism that periodically checks the status of a service, allowing it to automatically restart or take corrective action when it fails. However, in some cases, the healthcheck may not accurately reflect the service's status, leading to potential issues. In this article, we'll answer some frequently asked questions about the feature request to make the healthcheck actually do a healthcheck.

Q: What is the current state of healthchecks in the application?

A: Currently, the healthcheck is implemented as a separate endpoint, /thc. When this endpoint is called, it returns a 200 status code, indicating that the service is healthy. However, as the error message suggests, this may not always be the case.

Q: Why is the current healthcheck not accurate?

A: The current healthcheck may not accurately reflect the service's status because it only returns a 200 status code, without verifying the service's functionality. This can lead to false positives, where the service appears healthy when it's not, or delayed detection, where the service is not restarted or taken offline until it's too late.

Q: What is the proposed solution to improve the healthcheck?

A: The proposed solution is to modify the healthcheck endpoint to perform a real healthcheck, verifying the companion's status and checking video fetching. This will provide a more accurate indication of the service's status, reducing the risk of false positives and delayed detection.

Q: How will the proposed solution improve the healthcheck?

A: The proposed solution will improve the healthcheck in several ways:

Improved accuracy: The healthcheck will provide a more accurate indication of the service's status, reducing the risk of false positives.
Early detection: The healthcheck will detect issues earlier, allowing for prompt action to be taken to resolve the problem.
Reduced downtime: By automatically restarting the service when it fails, the healthcheck can reduce downtime and improve overall system reliability.

Q: What are the benefits of implementing a real healthcheck?

A: The benefits of implementing a real healthcheck include:

Improved accuracy: The healthcheck will provide a more accurate indication of the service's status, reducing the risk of false positives.
Early detection: The healthcheck will detect issues earlier, allowing for prompt action to be taken to resolve the problem.
Reduced downtime: By automatically restarting the service when it fails, the healthcheck can reduce downtime and improve overall system reliability.

Q: How can the proposed solution be implemented?

A: The proposed solution can be implemented by:

Modifying the healthcheck endpoint: Update the /thc endpoint to perform a real healthcheck, verifying the companion's status and checking video fetching.
Implementing companion status verification: Add code to verify the companion's status, ensuring that it's functioning correctly.
Adding video fetching check: Implement a check to verify the companion can fetch videos, providing a more accurate indication of the service's status.

Q: What are the next steps for implementing the proposed solution?

A: The next steps for implementing the proposed solution include:

Expanding the healthcheck: Expand the healthcheck to verify other aspects of the service, such as database connectivity or API availability.
Implementing automated restart: Implement automated restart of the service when it fails, reducing downtime and improving overall system reliability.