Hands‑on DevOps operations using Docker, K8s, Jenkins, and Ansible—empowering ops professionals to grow together through sharing, discussion, knowledge consolidation, and continuous improvement.
The article explains how a new WebSocket domain caused Nginx worker processes to repeatedly shut down, leading to timeout alerts, and provides step‑by‑step investigation methods and a configuration fix using the worker_shutdown_timeout directive.
When Kafka backs up and Logstash fails to write to Elasticsearch with a 403 cluster_block_exception, the index is locked by a write block, which can be resolved by clearing the index.blocks.write setting via the Elasticsearch API or Kibana dev tools.
This guide explains how to use the Elasticsearch GET /_cluster/allocation/explain API to identify throttling deciders, interpret the underlying allocation limits, and adjust persistent or transient cluster routing settings—such as node_concurrent_recoveries and indices.recovery.max_bytes_per_sec—to resolve shard allocation bottlenecks.
This guide shows how to write a Python script that sends a PUT request to Nacos to register or deregister a service instance, parses the JSON response, and reports success or failure based on the returned code and weight parameter.
This guide walks through a complete automated deployment workflow—including Maven build, rsync transfer, graceful shutdown of Nginx and Eureka services, service restart, health checks, and final bring‑up of both Eureka and Nginx—using shell commands and parameterized variables.
This guide shows how to write a Python script that constructs a service health URL from command‑line arguments, sends an HTTP request using the requests library, parses the JSON response, and raises an error if the service status is not "UP", providing clear success or failure feedback.
This guide shows how to create Bash scripts that mark an Nginx upstream server as down or up by editing the upstream configuration via SSH and then hot‑reload Nginx, providing a repeatable automation workflow for service deployment and rollback.
This guide shows how to create two Python scripts that use the Eureka REST API to set a service instance's status to OUT_OF_SERVICE for taking it offline and to UP for bringing it back online, handling command‑line arguments, constructing URLs, sending PUT requests, and checking responses.
This guide explains how to configure Nginx rate limiting using limit_req_zone and limit_req directives, covering syntax, parameters, burst handling, and a complete example that demonstrates setting a shared memory zone, request rate, burst buffer, and nodelay behavior for efficient traffic control.
Learn two practical Nginx configurations to prevent browsers from caching HTML files by setting appropriate Cache-Control, Pragma, and Expires headers, with examples for both standard location blocks and conditional directives, ensuring fresh content delivery for your web applications.
