Case Studies

Problem: After upgrading the Jenkins Active Choices Plugin from version 2.6.1 to 2.8.1, the client’s Jenkins instance began exhibiting critical malfunctions in jobs that utilized multi-level reactive reference parameters. These parameters, implemented via Active Choices Reactive Reference Parameter fields, rely on Groovy scripts to dynamically populate choices based on the values of one or more […]

Problem: The client reported a sudden and significant drop in Apache Cassandra performance on a 4-node cluster. The issue appeared without any recent configuration or infrastructure changes. The application started experiencing frequent timeouts, and restarting Cassandra services on all nodes did not resolve the problem. The client provided various monitoring graphs, system logs, and other […]

Problem: The client needed to scale their production Cassandra cluster from 6 nodes to 12 nodes (3 to 6 nodes per data center) without any downtime. Their existing setup includes Cassandra version 4.1.6, with two data centers (PROD and DR), each containing 3 nodes, forming a 6-node cluster with a replication factor of 3 and […]

Problem: The client encountered an issue with desynchronization of nodes in an ETCD cluster running on RHEL 8.8. Error logs indicated significant disk write delays (slow fdatasync), which caused the Patroni cluster to fail and become unavailable. Process: Step 1 – Initial Analysis The expert asked the client to check the health of the cluster […]

Problem: The client needed to implement audit logging for their PostgreSQL 15 databases. Specifically, they wanted to track user actions such as: Configuration changes Creation, deletion, or modification of objects (documents, users, settings) Attempts to access forbidden resources Privilege escalation attempts Additionally, they requested that auditing be limited only to administrative users, not applied globally […]

Problem: The client encountered frequent master (manager) re-elections in their production Docker Swarm cluster, despite having the dispatcher-heartbeat value set to 2 minutes. These re-elections were happening within fractions of a second, causing concerns around Swarm stability and service availability. The client’s Docker environment was based on version 1.13.1 running on RHEL 7.9. Key symptoms […]

Problem: The client faced recurring Kafka sink connector failures (e.g., chf-cdr-sftp-sink-connector) in a Kubernetes environment (Kafka 3.2.0 with three brokers and ZooKeeper). The failures were caused by corrupt messages at specific offsets, leading to task crashes. Despite skipping corrupt offsets and restarting connectors, the issue persisted, requiring a more permanent solution. Process: Step 1: Environment […]

Problem: The client faced an issue integrating Jenkins with Keycloak for authentication. While the Jenkins UI successfully authenticated users via Keycloak, API calls from backend services were failing. According to Jenkins’ documentation, API requests should be authenticated using an API token, but despite following the recommended steps, the client encountered authentication failures (403 Forbidden & […]

Problem: The client experienced issues with Docker Swarm configuration in production. Specifically, when a container restarted, the application failed to recover properly. The client requested a review of the configuration to identify the root cause and potential improvements to enhance the cluster’s functionality. Process: Step 1: Initial Investigation The client provided details of the Docker […]