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Observability questions

Focused answers for definitions, architecture choices, troubleshooting, pricing, and evaluation.

Illustration of log collection and monitoring
Explainer

Configure rsyslog for Rails on Elastic Beanstalk

Send Rails syslog events to a central receiver with Elastic Beanstalk configuration, and distinguish that route from CloudWatch log streaming.

  • Engineering
  • Explainer
2 min read
Illustration of server operations and request logs
Explainer

Serve different directories under one Nginx subdomain

Map URL prefixes to separate directories with root and alias, handle trailing slashes, and verify single-page application routes.

  • Engineering
  • Explainer
3 min read
Configure Log4j loggers programmatically
Explainer

Configure Log4j loggers programmatically

Build a Log4j 2 configuration in code, distinguish initialization from reconfiguration, and recognize the limits of legacy Log4j 1.x APIs.

  • Engineering
  • Explainer
2 min read
Illustration of log collection and monitoring
Explainer

Understand syslog message fields: PRI, timestamp, and tag

Read RFC 3164 and RFC 5424 messages, decode facility and severity, and recognize timestamp and whole-message size limits.

  • Engineering
  • Explainer
2 min read
Illustration of metrics, monitoring, and technical investigation
Explainer

Troubleshoot context deadline exceeded in Prometheus

Find which operation timed out, then check query cost, scrape duration, resources, and the Grafana or proxy timeout.

  • Engineering
  • Explainer
3 min read
Convert between bytes and strings in Python illustration
Explainer

Convert between bytes and strings in Python

Decode bytes into text and encode strings into bytes with the right character encoding, including invalid-byte handling and Base64 output.

  • Engineering
  • Explainer
2 min read
Illustration of application modules working together
Technical guide

Copy an SSH public key to the clipboard

Copy an SSH public key on macOS, Linux, Windows, or WSL, and preserve the complete key without exposing its private counterpart.

  • Engineering
  • Technical guide
2 min read
Illustration of application modules working together
Technical guide

Fix “Could not open a connection to your authentication agent”

Restore access to ssh-agent, load the intended key, and avoid starting a new agent for every terminal.

  • Engineering
  • Technical guide
3 min read
Illustration of Git history and collaboration
Technical guide

Create a Git tag and publish it on GitHub

Create and push a specific Git tag, distinguish annotated tags from signatures and releases, and handle an incorrect release marker.

  • Engineering
  • Technical guide
3 min read
Illustration of Git branches and commit history
Technical guide

Create a Git branch from another branch

Choose a local or remote-tracking branch as a starting point, control upstream tracking, and understand how the new branch diverges.

  • Engineering
  • Technical guide
3 min read
Illustration of Git history and collaboration
Technical guide

Export uncommitted Git changes as a patch

Export staged, unstaged, new, and binary files as a Git patch; check application, handle conflicts, and preserve commits with format-patch.

  • Engineering
  • Technical guide
3 min read
Illustration of scheduled jobs, logs and Linux operations
Explainer

Fix “No MTA installed, discarding output” in cron

Keep cron output in a log, configure mail delivery, or move the job to a systemd timer. Learn what the warning does and does not prove.

  • Engineering
  • Explainer
3 min read