Found 25 results for: Real-time Apps
Building Prometheus from source on a host with older Go and Node than the repo asks for: what the build does, what warns, and how I verified the result.
A Bun or Node.js service can be slow on a VPS because of CPU steal or slow disks. How to measure both, fix the host first, and then compare runtimes fairly.
A reference for lowering a cloud bill: measure first, right-size, use Spot for interruptible work, schedule capacity, compare regions, and track egress.
How an Nginx API gateway with rate limiting and upstream keepalive, plus an opossum circuit breaker, limits cascading failures between microservices (2022…
How to set up a single-node edge MQTT aggregator with K3s and WireGuard, and how to fix the faulty flags, units and sysctls that edge guides often repeat.
How to confirm that MySQL 5.5 is stuck on disk I/O, and how to tune the I/O scheduler, ext4 mount options and InnoDB settings for flash or fast virtual storage.
Why Kubernetes, Docker Swarm and Nomad clusters turn flaky on slow disks or stolen CPU, how to measure it with fio and vmstat, and what to change.
How to keep a local HAProxy in step with a ZooKeeper service registry: ephemeral znodes, a watcher that regenerates the config, and a graceful reload.
How to link a hyperscaler workload to a database on a Norwegian VPS with WireGuard, what the tunnel does not fix, and the common mistakes in such setups.
Trivy exits 0 even with CRITICAL findings. I built it from source and made it a real CI gate, then found a secret-scan skip that a green result can hide.
Why a Prometheus stack stalls under load, and how to fix it: federation, a lean node_exporter, recording rules, WAL-friendly storage and a locked-down firewall.
How to run a three-node NATS JetStream cluster (server 2.6, nats.go 1.13) with replicated streams, authentication, correct acks and sane OS limits.
How to keep slow jobs out of the web request path with RabbitMQ, Celery 3.0 and Nginx 1.2 on Debian 7, with corrected configuration and the limits of the setup.
How to move a large live PostgreSQL or MySQL database to a new server with streaming replication and a short write freeze, including the pitfalls in common…
How to tell when an OpenVZ container is being refused resources: read user_beancounters, interpret failcnt, and shrink MySQL and Apache to fit the limits.
Why Apache prefork wastes RAM on static files and slow clients, and how a lighttpd front end plus tuned MaxClients and keep-alive fixes it on CentOS 5.
A 2009 reference for VPS users on container-based hosting: why "Cannot allocate memory" appears while free shows RAM, and how to read and fix it.
Official Supabase Docker stack on a clean Ubuntu sandbox: the pooler and Edge Functions crash-looped. Why, and a compose override that fixed both, with tests.
Pods lose DNS after an egress NetworkPolicy is applied. This article covers the wrong namespace label, the missing TCP port 53 rule and a tested-in-theory fix.
Control planes built on etcd or Raft fail on slow disks. How to test fsync latency, pick between Kubernetes, K3s and Nomad, and prepare a K3s node.
How to run a private, key-only Git server with Gitolite 2.x on CentOS 6, with access rules kept in a Git repository. Covers latency, I/O, and backups.
How to replace hand-run kubectl apply with a pull-based GitOps flow: Argo CD, Kustomize overlays, Sealed Secrets and a CI job that only edits an image tag.
Replace trust-by-network-location with encrypted, authenticated links: WireGuard between nodes, nginx client certificates and hardened SSH with a second factor.
A reference setup for Postfix on CentOS 6 (2012): fix mail rejected or sent to spam with matching DNS, restricted SMTP, TLS submission with SASL, SPF and DKIM.
Why asynchronous replication can lose committed transactions, and how MySQL 5.5 semisync and PostgreSQL 9.1 synchronous replication address it on a CentOS 6…