Both cron and systemd timers can run a command at 2 a.m. The difference is what happens the night it doesn't run, and how long it takes anyone to notice. A comparison by failure family, with a decision rule, the same job written both ways, and how to debug each one when it goes quiet.
The rule went red at 02:04 and nobody found out until 09:15. Rule evaluation and notification delivery are two different systems, and only one of them is visible in the UI. A practical setup for Grafana alert notifications to email, Slack and Telegram, plus how to detect the day delivery quietly stops.
Shared admin credentials work right up until someone resigns or an auditor asks who did what. Here's how to design client AWS account access around cross-account roles, unique external IDs and per-engineer attribution, so twenty accounts need zero shared keys and revocation is one action.
Most AWS cost work goes wrong because it starts with the biggest line item, which is also the riskiest. Order the work by blast radius instead: free networking and storage fixes first, performance envelopes one workload at a time, and commitments last. Includes the commands to find the waste and the cuts that look harmless and are not.
Most AWS accounts have dozens of CloudWatch alarms and about three anyone trusts. A practical guide to missing-data settings, M-out-of-N evaluation, metric math, composite alarms and mute rules, and how to test the notification path before you need it.
n8n's Prometheus endpoint tells you the process is alive and busy. It does not tell you a workflow stopped producing correct output. This post walks through the three failure families that slip past a default n8n dashboard, the PromQL that catches each one, and how to close the gap with a second source of truth from the executions API.
Choosing between an Application Load Balancer and API Gateway is not a feature comparison. It is a choice of hard limits, a billing curve and an authentication story. Here is how each one bills you, which constraints surface months later, what ALB's native JWT validation changes, and a decision procedure you can run in ten minutes.
A backfill that exits zero can still be missing a week of data, and nothing will tell you. This is a practical guide to the failure families behind silent gaps: pagination drift under a mutating source, retries that duplicate pages, prefix layouts designed for writes instead of reads, the seam where backfill meets live ingest, and the storage class rules that make mistakes expensive. Includes deterministic key derivation, S3 conditional writes, Athena partition projection, and a per-window manifest pattern that turns completeness into something you can query.
Connecting Salesforce to Amazon Bedrock Knowledge Bases takes an afternoon. Making sure the assistant does not read people records they were never allowed to see takes longer. A practical walkthrough of the connector, the permission model it quietly drops, and the two architectures that actually hold up.
High I/O wait is a symptom, not a diagnosis. It rises when nothing is wrong and stays flat when something is badly wrong, and it only sees one layer of the storage stack. This is how to read iowait and PSI correctly, then work through the five failure families that actually produce storage stalls: device saturation, memory pressure, synchronous writes, throttling, and latency that lives above the block layer entirely.