Check Kafka partition leaders and in-sync replicas
Read partition leaders, replicas and ISR with kafka-topics.sh and kcat, find under-replicated or leaderless partitions, and avoid advertised listener traps.
Guides
Step-by-step guides for inspecting MySQL, Redis, MongoDB, Kafka, ClickHouse and Kubernetes safely, with commands you can copy.
Create a read-only MySQL user for your desktop client
A read-only flag in a client is not a permission boundary. Create a MySQL account that can only SELECT, scope it to one schema and verify the grants.
Kubernetes RBAC for read-only debugging
A namespace Role that can read Pods, logs, events and Deployments but not Secrets or anything writable, a ServiceAccount token kubeconfig, and how to verify it.
MongoDB pagination: skip vs range queries
skip() gets slower with every page and shifts when data changes. Range queries on an indexed sort key stay fast. When to use each, with Extended JSON examples.
Reach a private Kubernetes API server through an SSH bastion
Three ways to use kubectl against an API server that only a bastion can reach, how TLS server names break, and how a tunnel-aware client avoids it.
Read the logs of a crashed container in K3s
When a Pod restarts, kubectl logs shows the new container. How to get the previous instance's logs, exit code and events, and what to do when they are gone.
Redis SCAN vs KEYS in production
KEYS walks the whole keyspace in one blocking call. SCAN pages through it. How to use SCAN correctly and how to lock KEYS out of a read-only Redis ACL user.
Release Kubernetes workloads with immutable image digests
Tags can be moved; digests cannot. How to find an image's sha256 digest, deploy by digest, handle multi-arch indexes and roll back to exactly what ran before.
Run read-only ClickHouse queries over HTTP
Query ClickHouse over HTTP with readonly, result limits and timeouts, then enforce them on the server with a SELECT-only user and a settings profile.
Use a local LLM for SQL suggestions
Run an OpenAI-compatible model on your own machine with Ollama, LM Studio or llama.cpp, test the endpoint with curl, and point a desktop SQL client at it.