Kubernetes Troubleshooting:
OpsCruise's Guide to Solving Some of Kubernetes’ Toughest Operational Issues
Large and small organizations alike are adopting Kubernetes at an incredible rate. It is fast becoming the new standard when developing modern applications. Reasons for this include:
- Developers aren’t required to manage infrastructure
- The ability to manage everything as code
- Easy application environment isolation
- Deployment and management of applications using fine-grained scheduling controls
While Kubernetes has become the de facto standard for cloud-native applications, there are a number of challenges given its breadth and scope, along with applications it’s running, the underlying infrastructure, and application deployment.
For example, application components managed by Kubernetes often communicate with services external to the cluster -- this can include API calls and 3rd party SaaS or cloud PaaS services. When applications with these types of external calls fail, there’s a difficult challenge of understanding where the issue lies. Is it the application? Is it the Kubernetes configuration? Is it infrastructure? Is it an in-cluster dependency? Or, is it directly related to the external service calls?
Learning how to identify the fault domain, and doing it quickly, is key to getting your applications back into a functioning state as fast as possible.
Kubernetes Application Lifecycle Phases
Applications running inside of Kubernetes typically run into problems in one of the following phases:
Preparation Phase
- This phase ensures all configured prerequisites are set and ready for the Pod to run.
- Problems here can be related to issues setting up infrastructure, failure of required configuration, or other pre-startup tasks.
Initialization Phase
- This phase receives configuration and uses it to set up overall application configuration parameters.
- Problems here can involve missing dependencies at the application level and failures due to unhealthy Pods, among others.
Run Phase
- This phase has the application performing its core functions.
- Failures here have a very wide range of causes, from application specific issues and unhandled exceptions, to failing infrastructure, such as network failures and disk issues, and many, many others.
Types of Kubernetes Errors
Kubernetes errors are all unique. They can occur across phases, as mentioned above, and can include loops, crashes, or backoffs. Notwithstanding the complexity of a particular Kubernetes issue, it generally falls into one of a few different categories. These can include:
- Access to required resources
- Configuration of prerequisites
- Performance issues
- Functional failures
When errors show up across phases, it is necessary to identify and resolve them with as much speed as possible. This gets complicated: each phase can have different classes of issues. Quick identification is the key to a quick resolution. This is what brings applications back to a healthy state.
E-Book Topics
In our e-book, we delve into the various types of issues and discuss problem scenarios you’ll likely encounter in Kubernetes-based applications, how to identify them, and how to resolve them.
Learn about diagnosing:
- Pod initialization issues
- Application dependencies causing Pod failures
- Problems with Pods crashing after running successfully
- Network Policy traffic blocking scenarios
- and more..
Download the Kubernetes Troubleshooting: A hands-on practitioner's guide e-book to solving some of Kubernetes’ toughest operational issues today and learn how to get started troubleshooting the right way.