Lesson 1Interpreting logs for web apps and system services: /var/log/syslog, /var/log/messages, journald (journalctl), application-specific logs and how to filter themLearn fi read and filter Linux and macOS logs fi web apps and services, yuh hear. Yuh guh work wid syslog, journald, and app logs, using journalctl, grep, and other tools fi isolate issues, link up events, and build repeatable log queries, real talk.
Syslog layout and common log locationsUsing journalctl filters and time rangesReading web server access and error logsFiltering logs with grep, awk, and sedCorrelating multi-service events by timestampLesson 2Process identification and analysis: ps aux, pstree, pmap, lsof, strace — finding the offending process and inspecting behaviorDevelop skills fi find and check problematic processes, yuh zeet. Using ps, pstree, pmap, lsof, and strace, yuh guh map process hierarchies, check open files and ports, trace system calls, and link resource spikes to specific PIDs, no joke.
Locating heavy processes with ps and topVisualizing parents and children with pstreeInspecting memory maps using pmapFinding open files and ports with lsofTracing system calls and hangs with straceLesson 3Network diagnostics on Linux: ss, netstat, ip a, ip route, ethtool, ifconfig — how to read interface and route informationPick up skills fi diagnose Linux and macOS network issues, seen. Yuh guh use ss, netstat, ip, ifconfig, and ethtool fi check sockets, routes, and interfaces, spot listening services, and verify connectivity and throughput problems, yuh know.
Listing listening ports with ss and netstatInspecting IP addresses and routes with ipChecking link speed and duplex with ethtoolUsing ifconfig and ip for interface statusDetecting common routing and DNS issuesLesson 4Disk I/O investigation: iostat, iotop, blktrace, checking filesystem types and mount optionsCheck out disk I/O bottlenecks and filesystem behavior, realness. Yuh guh use iostat, iotop, and blktrace, inspect filesystem types and mount options, and relate I/O patterns to application workloads and latency issues, straight up.
Spotting I/O saturation with iostatFinding I/O-heavy processes using iotopTracing block-level activity with blktraceComparing filesystem types and tradeoffsReviewing mount options for performanceLesson 5Commands for live monitoring: top, htop, vmstat, iostat, sar, mpstat — exact usage examples and interpretationCheck live monitoring tools fi understand real-time system behavior, yuh see. Yuh guh use top, htop, vmstat, iostat, sar, and mpstat fi spot CPU, memory, and I/O bottlenecks, interpret key fields, and capture short performance snapshots, fi real.
Reading CPU and load in top and htopUsing vmstat for memory and swap insightMonitoring disk I/O with iostat and iotopHistorical snapshots with sar and mpstatExporting command output for later reviewLesson 6Analyzing web server performance: nginx/apache status modules, access/error logs, slow request analysis, HTTP status patternsLearn fi check web server performance pon nginx and Apache, yuh zeet. Yuh guh read status modules, analyze access and error logs, detect slow requests, and interpret HTTP status patterns fi tell client issues from server bottlenecks, no doubt.
Enabling and reading nginx status endpointsUsing Apache mod_status and server-statusIdentifying slow requests and timeoutsAnalyzing HTTP status code distributionsDetecting bots, scans, and abusive trafficLesson 7Long-term remediation: capacity planning, resource limits (systemd, cgroups), tuning kernel and web server configs, application profiling tools and when to use themPlan long-term fixes instead a repeat firefighting, seen. Yuh guh practice capacity planning, set resource limits wid systemd and cgroups, tune kernel and web server parameters, and choose profiling tools fi guide code and config changes, true talk.
Collecting data for capacity planningConfiguring systemd unit resource limitsApplying basic cgroup constraints safelyTuning kernel and web server parametersSelecting and using app profiling toolsLesson 8Understanding system resource metrics: CPU, memory, I/O, network — what to monitor and whyUnderstand core system metrics and what dem show bout health, yuh know. Yuh guh interpret CPU, memory, disk, and network indicators, learn safe thresholds, and decide which metrics matter most fi web workloads and background services, fi sure.
CPU utilization, load average, and run queuesMemory usage, cache, and swap behaviorDisk throughput, latency, and queue depthNetwork bandwidth, errors, and dropsChoosing alert thresholds for key metricsLesson 9Temporary mitigation techniques: restarting services, adjusting process niceness, freeing caches, taking services offline gracefully — commands and expected outcomesApply safe, temporary fixes during incidents, real talk. Yuh guh restart services, adjust niceness, manage caches, and gracefully take services offline, understanding commands, risks, and how fi verify dat mitigations work proper.
Safely restarting critical servicesAdjusting process priority with nice and reniceFreeing page cache and dentries carefullyPutting web apps into maintenance modeVerifying mitigation impact on metrics
