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Notes on DevOps, Kubernetes, self-hosted infrastructure and consulting.
11 posts tagged operasyon · clear filter
October 4, 2026
PodDisruptionBudgets and Node Drains in Kubernetes: Writing the Budget and Why Maintenance Gets Stuck
A PodDisruptionBudget only limits voluntary disruptions, and a badly written one either protects nothing or blocks node drains forever. Choosing between minAvai...
kubernetes yuksek-erisilebilirlik operasyon
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October 3, 2026
Zero-Downtime Secret Rotation: Dual Keys, Alternating Users and the Consumers Left Behind
Rotation outages are caused by consumers, not by the value. Overlap windows, dual keys and alternating users, measuring the cutover, and the long-running proces...
sir-yonetimi guvenlik operasyon
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September 29, 2026
DNS Resolution in Kubernetes: ndots, Search Domains, CoreDNS Caching and the Five-Second Stalls
Why a pod turns one external lookup into eight DNS queries, what lowering ndots breaks, when autopath and NodeLocal DNSCache are worth it, where the exact five-...
kubernetes operasyon performans
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September 26, 2026
Kubernetes Resource Requests and Limits: CPU Throttling, OOMKilled and QoS Classes
A request is the scheduler's reservation, a limit is the kernel's quota. Why CPU gets paused while memory gets killed, how QoS classes decide eviction order, an...
kubernetes performans operasyon
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September 25, 2026
Zero-Downtime Schema Migrations: Expand and Contract, Locks and PostgreSQL Pitfalls
Rolling deploys are not enough; a schema change breaks the moment old and new versions run side by side. How to migrate PostgreSQL without downtime using expand...
postgresql backend saas
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September 24, 2026
Stateful Resources Under Helm: Renames, resource-policy and CRD Pitfalls
Helm deletes a renamed PVC, restarts a StatefulSet on empty disks, regenerates passwords on every upgrade and never updates a CRD. Why data gets lost when state...
kubernetes devops operasyon
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September 22, 2026
Zero-Downtime Deployments in Kubernetes: Probes, preStop and Getting Graceful Shutdown in the Right Order
A rolling update alone does not give you zero downtime. Unless readiness and startup probes, a preStop delay, terminationGracePeriodSeconds, maxUnavailable and...
kubernetes guvenilirlik operasyon
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September 21, 2026
Silent Failures in Bash Scripts: set -e, pipefail and Where Strict Mode Abandons You
set -euo pipefail does not make your script safe, it only gets you started. -e switching off inside function bodies, pipefail failing on SIGPIPE, -u ignoring em...
linux otomasyon operasyon
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September 20, 2026
Why Scheduled Jobs Break Quietly: Missed Runs, Overlap and Single Instance in cron, systemd Timers and Kubernetes CronJobs
Scheduled jobs break quietly in three ways: the missed run, the overlapping run and the failure nobody sees. How cron, systemd timers and Kubernetes CronJobs an...
linux kubernetes operasyon
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September 18, 2026
Backups are not enough: run restore drills
A green backup job gives false confidence, and an untested backup is not a backup. We cover the silent traps we hit, valid but incomplete archives, stale locks,...
yedekleme felaket-kurtarma operasyon
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September 16, 2026
The PID 1 Problem in Containers: Zombie Processes and When You Need an Init System
The first process in a container is not an ordinary process as far as the kernel is concerned. Here is how that difference leads to zombie process buildup, how...
docker kubernetes linux
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