From 35f690b6fa166b704d6f3108e63a704319721f60 Mon Sep 17 00:00:00 2001 From: Jim DeFabia Date: Fri, 15 Nov 2024 14:35:12 -0500 Subject: [PATCH] HPCC-33000 Add a Troubleshooting chapter to Containerized manual Signed-off-by: Jim DeFabia --- .../ContainerizedHPCCSystemsPlatform.xml | 2 + .../TroubleshootingHelmDeployments.xml | 513 ++++++++++++++++++ 2 files changed, 515 insertions(+) create mode 100644 docs/EN_US/ContainerizedHPCC/ContainerizedMods/TroubleshootingHelmDeployments.xml diff --git a/docs/EN_US/ContainerizedHPCC/ContainerizedHPCCSystemsPlatform.xml b/docs/EN_US/ContainerizedHPCC/ContainerizedHPCCSystemsPlatform.xml index a6cf61bccfb..42c59d9c7b5 100644 --- a/docs/EN_US/ContainerizedHPCC/ContainerizedHPCCSystemsPlatform.xml +++ b/docs/EN_US/ContainerizedHPCC/ContainerizedHPCCSystemsPlatform.xml @@ -227,4 +227,6 @@ + diff --git a/docs/EN_US/ContainerizedHPCC/ContainerizedMods/TroubleshootingHelmDeployments.xml b/docs/EN_US/ContainerizedHPCC/ContainerizedMods/TroubleshootingHelmDeployments.xml new file mode 100644 index 00000000000..b67944e90db --- /dev/null +++ b/docs/EN_US/ContainerizedHPCC/ContainerizedMods/TroubleshootingHelmDeployments.xml @@ -0,0 +1,513 @@ + + + + Troubleshooting Containerized Deployments + + + Introduction + + Helm is a powerful package manager for Kubernetes, simplifying the + deployment and management of complex applications. However, even with + Helm, deployment issues can arise. This chapter will guide you through + common troubleshooting steps for Helm deployments. Command-line tools, + such as kubectl and helm are + available for both local and cloud deployments. + + + + Useful Helm Commands + + Here are some useful Helm commands for troubleshooting. + + List deployments using this command + in a terminal window: + + helm list + + This returns all installed Helm releases. + + If you have multiple namespaces, use this command: + + helm list -A + + Returns all installed Helm releases across all namespaces. + + Get the status of a specific + release using this command in a terminal window: + + helm status <release-name> + + This returns the status of a specific release. + + Get the user supplied values for a + release using this command in a terminal window: + + helm get values <release-name> + + By effectively using these Helm commands, you can quickly identify + and resolve issues with your Helm deployments. Remember to consult the + official Helm documentation for more detailed information and specific use + cases. + + + + Check the Status of Pods + + Pods are the smallest deployable units of computing that can be + created and managed in Kubernetes. Checking the status of pods is a + fundamental step in troubleshooting Kubernetes deployments. By monitoring + pod status, you can quickly identify and address potential issues, + ensuring the health and performance of your applications.   + + The HPCC Systems platform has one or more pods for each component of + a deployed system. + + To get a quick overview of pod status, use the following command in + a terminal window: + + kubectl get pods + + This lists all pods in your cluster, along with their status, + restart count, and other details. + + If you have deployments to more than one namespace, use this + command: + + kubectl get pods -A + + This lists all pods in all namespaces. + + Each pod should indicate a status of Running and have a matching number of pods + displayed in the READY column. + + Check the RESTARTS column, a high + number of restarts may indicate issues. + + + Identifying Other Issues and Their Root Cause + + Pending Status: + + Insufficient Resources + + + The pod might be waiting for resources like CPU or memory + to become available. + + + + + Scheduling Failures + + + There might be scheduling conflicts or node issues + preventing the pod from being scheduled. + + + + + Running Status: + + + + High Restart Count + + + Frequent restarts could indicate issues with the pod's + configuration, image, or underlying infrastructure. + + + + + Resource Constraints + + + The pod might be experiencing resource limitations, leading + to performance degradation or crashes. + + + + + Failed Status: + + + + Container Failures + + + One or more containers within the pod might have failed due + to errors or crashes.   + + + + + Termination Signals + + + The pod might have been intentionally terminated, + potentially due to a deployment or scaling operation. + + + + + + + + Describe a Pod + + Use the kubectl command-line tool + to get detailed information about pods. By describing a pod, you can gain + valuable insights into its current state, configuration, and resource + utilization. + + To get detailed information about a pod, use the following command + in a terminal window: + + kubectl describe pod <pod-name> + + The output provides detailed information about the pod, + including: + + + + Events + + + A timeline of events related to the pod's lifecycle. If + there are issues with the deployment, they are commonly found in + this section. + + + + + Containers + + + Information about the containers running within the + pod. + + + + + Status + + + The current status of the pod. + + + + + Conditions + + + The conditions that the pod must meet to be considered + running. + + + + + If you have deployments to more than one namespace, use this + command: + + kubectl describe pod <pod-name> -A + + This describes the pod across all namespaces. + + By carefully analyzing this information, you can: + + + + Identify and troubleshoot issues + + + Pinpoint the root cause of problems, such as resource + constraints, configuration errors, or network connectivity + issues. + + + + + Monitor pod health and performance + + + Track the pod's status, resource usage, and event history to + ensure it's operating as expected. + + + + + Optimize resource allocation + + + Adjust resource requests and limits to improve performance + and cost-efficiency. + + + + + Gain insights into Kubernetes scheduling and resource + management + + + Learn how Kubernetes allocates resources to pods and handles + failures. + + + + + By mastering the art of describing pods, you can become a more + effective Kubernetes administrator and troubleshoot your deployments with + confidence. + + + + Check the Status of Services + + Services expose applications running on a cluster. + + The kubectl get services command is a powerful + tool for troubleshooting Kubernetes deployments. It provides a concise + overview of the services running in your cluster, helping you identify + potential issues and their root causes. + + To get a quick overview of services status, use the following + command in a terminal window: + + kubectl get services + + This lists all services in your cluster, along with their type, + internal and external IP addresses, port, and uptime (Age). + + If you have deployments to more than one namespace, use this + command: + + kubectl get service -A + + This lists all services in all namespaces. + + If a service that should have an external IP listed does not have + one displayed, that pod has an issue. + + + + Describe a Service + + Use the kubectl command-line tool + to get detailed information about a service. By describing a service in + Kubernetes, you can gain valuable insights into its configuration, health, + and how it interacts with pods. + + To get detailed information about a service, use the following + command in a terminal window: + + kubectl describe service <service-name> + + The output provides detailed information about the service, + including the service's IP address, port, selectors, and other + details. + + If you have deployments to more than one namespace, use this + command: + + kubectl describe service <service-name> -A + + This describes the service across all namespaces. + + + + Viewing Pod Logs + + Viewing pod logs is a crucial step in troubleshooting Helm + deployments because it provides real-time insights into the behavior and + errors occurring within your application containers. By analyzing these + logs, you can quickly identify and address a wide range of issues. + + To view the logs of a specific pod, use the following command in a + terminal window: + + kubectl logs <pod-name> + + This returns the entire log for a pod. + + To tail the logs and see real-time output: + + kubectl logs -f <pod-name> + + If the pod has more than one container, use this command to get logs + for a specific container: + + kubectl logs <pod-name> -c <container-name> + + + + Viewing Service Logs + + While services themselves don't produce logs, you can view the logs + of the pods that are running the service. + + To do this, you'll need to identify the pods that are selected by + the service's selector. You can use the describe command to see the + selector: + + kubectl describe service <service-name> + + Once you know the selector, you can list the pods that match + it: + + kubectl get pods -l <selector-label> + + Then, you can view the logs of those pods using the logs + command: + + kubectl logs <pod-name> + + + + Effective Log Analysis + + Here are some additional tips for effective log analysis for + troubleshooting. + + + + Filter and Search Logs + + + Use kubectl logs options to filter logs + by timestamp, container name, or specific keywords to focus on + relevant information. + + For example: + + kubectl logs <pod-name> --since=10m + + Filters logs from a specific time. + + Even though kubectl logs doesn't have a + direct keyword search option, you can use tools like + grep to filter the output. + + For example: + + kubectl logs <pod-name> | grep "TLS" + + + + + Correlate Logs with Metrics + + + Combine log analysis with monitoring metrics to gain a + holistic view of application performance. + + + + + Leverage Logging Tools + + + Consider using advanced logging tools like Elasticsearch, + Logstash, and Kibana (ELK Stack) to centralize, aggregate, and + analyze logs from multiple pods and services. + + + + + Set Appropriate Log Levels + + + Configure your application to log at the appropriate level of + detail, balancing the need for informative logs with the risk of + excessive log verbosity. You can then use a filter to show only + those log entries that meet the criteria. + + + + + Monitor logs in real-time. + + + Monitoring logs in real-time can be useful to debug ongoing + issues. Use the following command: + + kubectl logs -f + + + + + + + Additional Troubleshooting Tips + + Here are some additional tips for troubleshooting your + deployments. + + + + Check your Helm chart configuration. + + + Ensure that your Helm chart(s) are configured correctly, with + accurate values for images, resources, and environment + variables. + + + + + Verify Image Availability. + + + Make sure that the images used in your Helm chart are + accessible and can be pulled by Kubernetes. + + + + + Inspect Resource Limits and Requests. + + + Review the resource limits and requests defined for your pods + and services. Insufficient resources can lead to performance issues + or pod failures. + + + + + Examine Kubernetes Logs. + + + Use the kubectl logs command to view the + logs of specific pods and containers. These logs can provide + valuable insights into errors and unexpected behavior. + + + + + Review Network Connectivity. + + + Ensure that your Kubernetes cluster has proper network + connectivity, both internally and externally. Network issues can + prevent pods from communicating with each other or with external + services. + + + + + Consider Persistent Volume Claims (PVCs). + + + If your application requires persistent storage, verify that + PVCs are provisioned correctly and that the underlying storage is + accessible. + + + + + By following these steps and tips, you can effectively troubleshoot + your containerized deployments and quickly identify the root cause of + issues. + +