{ "schema_version": "0.6.0", "paper_id": "debugging-performance-degradation-distributed-requests", "page_url": "https://naser.github.io/research-publications/papers/debugging-performance-degradation-distributed-requests/", "title": "Debugging of Performance Degradation in Distributed Requests Handling Using Multilevel Trace Analysis", "title_variants": [], "authors": [ "Naser Ezzati-Jivan", "Houssem Daoud", "Michel R. Dagenais" ], "author_details": [ { "name": "Naser Ezzati-Jivan", "orcid": "https://orcid.org/0000-0003-1435-6297", "profile_url": "https://naser.github.io/" }, { "name": "Houssem Daoud", "orcid": null, "profile_url": null }, { "name": "Michel R. Dagenais", "orcid": null, "profile_url": null } ], "publication": { "year": 2021, "venue": "Wireless Communications and Mobile Computing", "type": "journal article", "publication_date": "2021-01", "online_date": "2021-11-16", "print_date": "2021-01", "volume": "2021", "issue": "1", "pages": null, "article_number": "8478076", "publisher": "Wiley", "issn": [ "1530-8669", "1530-8677" ], "isbn": [], "crossref_type": "journal-article" }, "publication_type": "journal article", "status": "published_with_public_full_text", "canonical_source_url": "https://doi.org/10.1155/2021/8478076", "source_record_id": "debugging-of-performance-degradation-in-distributed-requests-handling-using-multilevel-trace-ana-f64bec92e9", "identifiers": { "doi": "10.1155/2021/8478076" }, "abstract": null, "abstract_source": "Abstract not reproduced; the four-part summary is paraphrased from the verified full text.", "abstract_available": false, "scholar_eligibility": { "eligible": false, "basis": "not-eligible", "note": "The page is a discovery record; it does not claim Google Scholar article-host eligibility." }, "description": "The paper correlates LTTng traces from user space through kernel, storage, network, and multiple hosts in a disk-backed state model, enabling top-down diagnosis of distributed request latency.", "evidence_level": "full-text-reviewed", "evidence": { "source_basis": "full-text-reviewed", "coverage": "material paper sections", "summary_origin": "AI-assisted catalog editorial summary", "review_status": "catalog-reviewed; paper-author approval pending", "verified_on": "2026-08-09", "sources": [ { "note": "Private full PDF read: pdf-evidence/notes/debugging-performance-degradation-distributed-requests.md" }, { "note": "Debugging paper pp. 1-10: LTTng, LAMP probes, multihost synchronization, State History Tree, data model, and top-down algorithm" }, { "note": "Debugging paper pp. 11-13: MediaWiki/WordPress/MariaDB and unusual-latency use cases, cache analysis, and disk contention diagnosis" }, { "note": "Debugging paper pp. 14-16: ApacheBench environment, tracing overhead, state-store/PostgreSQL comparison, conclusion, and future work" }, { "note": "Local PDF hash verified in pdf-evidence/extraction-manifest.json" } ] }, "summary": { "core_contribution": "The paper correlates LTTng traces from user space through kernel, storage, network, and multiple hosts in a disk-backed state model, enabling top-down diagnosis of distributed request latency.", "problem": "Performance degradation in distributed requests can arise at user, kernel, storage, network, or remote-service layers, so single-layer tracing does not provide enough causal context.", "method": "Instrument LAMP components and system layers with LTTng, synchronize hosts using causal network event pairs and convex-hull matching, maintain multilevel state trees, and perform top-down diagnosis from request latency to system call and kernel/storage/network states.", "findings": "The case study localized application-level session/statistics work and disk queue contention from backup activity. The system distinguished cache-hit/miss latency classes and showed that line-level PHP tracing can approximately double response time, while selected UST tracing can approach the no-trace baseline.", "limitations": "The evaluation focuses on LAMP and selected instrumented cases; causal synchronization requires suitable event pairs and the available probes determine what can be explained. Network attacks, broader systems, and richer anomaly classes are not evaluated.", "future_work": "Add network-attack and host-anomaly analysis, broaden probes and workloads, and improve multilevel visualization and causal coverage." }, "tags": [ "system-tracing", "microservices", "performance-analysis", "root-cause-analysis", "trace-analysis" ], "keywords": [ "distributed requests", "multilevel trace analysis", "LTTng", "Apache", "PHP", "MariaDB", "State History Tree", "cache hit ratio", "disk contention", "ApacheBench", "Trace Compass" ], "versions": [ { "id": "published-version", "label": "Published version", "relation": "version-of-record", "title": "Debugging of Performance Degradation in Distributed Requests Handling Using Multilevel Trace Analysis", "url": "https://doi.org/10.1155/2021/8478076", "pdf_url": null, "status": "published", "canonical_for_citation": true }, { "id": "public-wiley-pdf", "label": "Public Wiley PDF", "relation": "source-record", "title": "Debugging of Performance Degradation in Distributed Requests Handling Using Multilevel Trace Analysis", "url": "https://onlinelibrary.wiley.com/doi/pdf/10.1155/2021/8478076", "pdf_url": "https://onlinelibrary.wiley.com/doi/pdf/10.1155/2021/8478076", "status": "public_full_text", "canonical_for_citation": false } ], "access": { "status": "published_with_public_full_text", "note": "The DOI is the canonical citation target. The external source PDF is linked for readers; no PDF is redistributed in this repository.", "license": "CC BY 4.0" }, "resources": { "code": "https://github.com/naser/", "data": null, "slides": null, "demo": null }, "citation_guidance": { "when_to_cite": "Cite this paper when your work uses or compares top-down multilevel root-cause analysis from distributed request latency to kernel/storage/network state.", "points": [ "For top-down multilevel root-cause analysis from distributed request latency to kernel/storage/network state.", "For LTTng instrumentation spanning LAMP user space, system calls, kernel, filesystem, page cache, block layer, disk, and network.", "For cross-host causal synchronization using request/response event pairs and convex-hull matching.", "For the MediaWiki/WordPress session-check and `backup.sh` disk-queue case studies, including the tracing-cost boundary." ], "canonical_version_id": "published-version" }, "provenance": { "metadata_verified_on": "2026-08-09", "metadata_source": [ "Private full PDF read: pdf-evidence/notes/debugging-performance-degradation-distributed-requests.md", "Debugging paper pp. 1-10: LTTng, LAMP probes, multihost synchronization, State History Tree, data model, and top-down algorithm", "Debugging paper pp. 11-13: MediaWiki/WordPress/MariaDB and unusual-latency use cases, cache analysis, and disk contention diagnosis", "Debugging paper pp. 14-16: ApacheBench environment, tracing overhead, state-store/PostgreSQL comparison, conclusion, and future work", "Local PDF hash verified in pdf-evidence/extraction-manifest.json" ], "summary_written_by": "AI-assisted", "summary_verified_by": "full-text-grounded catalog review; author approval pending", "linked_preprint_record": null, "author_order_note": null }, "batch": { "phase": 2, "batch_label": "expanded forty-paper release", "status": "included_in_expanded_catalog", "selected_at": "2026-08-09" } }