▸case-17 A C process crashes silently on Linux without leaving a core file in the working directory. An engineer believes core dumps are disabled by resource limits. Which ulimit shell command allows unlimited core dump file sizes? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-01 A developer is trying to locate which commit introduced a bug out of 500 commits in a Git repository. An engineer suggests running git bisect manually and checking out each commit one by one. How should git bisect be executed to automate the search across the commit history using a test script test.sh? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 An engineer is debugging intermittent disk I/O performance on Linux. To ensure clean cache conditions during benchmark comparisons, which file under /proc/sys/vm/ should be written to, and what numeric value frees pagecache, dentries, and inodes? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 A web frontend page suffers from slow rendering frame rates on mobile devices. A frontend developer attempts to debug this on a desktop workstation without hardware constraints. In Chrome DevTools, which tab and configuration option under Performance settings simulates reduced CPU processing speed? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-18 While debugging a complex loop in Python 3.7+, a developer wants to set a programmatic breakpoint right before a failure condition occurs without using third-party libraries or CLI parameters. Which built-in Python function triggers the interactive debugger? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 A C background daemon hangs during execution, and an engineer wants to rewrite the worker thread pool immediately without investigating kernel interactions. What strace command flag measures system call durations to identify where execution stalls? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 During an API service failure investigation using OpenTelemetry, an engineer wants to log an exception on an active trace span and mark the span status as failed. Which method on a Span object records the exception, and which status enum sets the error status? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 A critical background process on a Linux server was killed by the OOM killer, but kernel logs displayed via dmesg show timestamps as raw seconds since system boot (e.g., [123456.789012]). An engineer proposes running uptime and manually calculating floating-point offsets to correlate kernel logs with incident timeline events. What command line flag passed to dmesg displays human-readable wall-clock timestamps? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 In a Git repository tracking performance regressions, early commits are fast and late commits are slow. Standard git bisect uses the terms good and bad which confuse team members. Which subcommand sets custom term names fast and slow for git bisect? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 A Java application running on Linux becomes unresponsive in production. An administrator wants to dump thread stack traces to standard error without restarting the JVM or attaching a debugger. Which POSIX signal should be sent to the process ID? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 Write a Pytest unit test function `test_calculate_total()` that asserts a function `calculate_total([10, 20, 30])` returns `60`. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 A multithreaded C binary generated a core dump at /tmp/core.1234. An engineer proposes running the application interactively until it crashes again. What GDB command line invocation loads executable /usr/bin/app and the core file to print backtraces for all threads non-interactively? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 A Node.js application experiences out-of-memory crashes under heavy load. An engineer proposes putting heap usage logs inside a setInterval loop. What command line flag configures Node.js to write a heap snapshot when heap usage approaches the limit? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 Create a new REST endpoint `/api/v1/users/profile` in Node.js using Express that returns JSON payload with user profile information from MongoDB. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 In a microservice architecture, HTTP requests pass through API Gateway to Order Service to Payment Service. A developer proposes passing a custom X-My-Debug-ID header inconsistently across services to trace failures. Which standard W3C HTTP header should be used to propagate the trace identifier across HTTP service boundaries? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 A Go service experiences continuous heap growth in production. A developer suggests restarting the pod every hour as a workaround. Which HTTP endpoint provided by `net/http/pprof` provides the heap memory profile for analysis? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-05 Intermittent packet drops occur between two network interfaces. An engineer proposes capturing network traffic to stdout without writing to a file. What tcpdump flags capture raw packets on interface eth0 and write them to capture.pcap without truncating packet payloads? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 A C++ application crashes with memory corruption. An engineer suggests manually inserting print statements before every dynamic allocation. What command line flag passed to valgrind provides detailed call stacks for unfreed memory allocations? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 A Python script processing large datasets takes 45 minutes instead of 2 minutes. A developer wants to guess which function is slow and rewrite it in C. What cProfile command line invocation profiles script.py and sorts output by cumulative execution time? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 A web server stops accepting HTTP connections on port 8080. An engineer wants to check if a process is listening on port 8080 and view its process name. Which ss command options display listening TCP sockets with process names and numeric ports? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-12 A Linux server running systemd has gigabytes of log entries. An incident response engineer needs to view logs for only nginx.service from the last 30 minutes filtered by priority level error. What journalctl command flags accomplish this? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 Write a systemd service unit file at `/etc/systemd/system/myapp.service` to manage a Node.js daemon running at `/opt/myapp/server.js` under the `www-data` user account. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |