apache/httpd
Nov 2024 – Feb 2026
13 Months active
Languages Used
CPythonTextApache ConfigurationMarkdownXMLYAML
Technical Skills
HTTP/2Network ProtocolsServer ConfigurationTestingACME protocolApache HTTP Server Module Development
Stefan Eissing
PROFILE
Stefan Eissing
Over thirteen months, contributed to apache/httpd by developing and maintaining core modules such as mod_md and mod_http2, focusing on certificate automation, HTTP/2 reliability, and server configuration. Leveraged C programming, Apache configuration, and Python scripting to deliver features like ACME profile support, HTTP/2 performance metrics, and enhanced error handling. Addressed cross-version compatibility, memory management, and security through targeted bug fixes and documentation improvements. Implemented robust testing and continuous integration practices to ensure stability across releases. The work improved TLS certificate lifecycle management, HTTP/2 throughput, and operational observability, supporting smoother deployments and reducing incidents in high-load production environments.
Overall Statistics
Feature vs Bugs
46%Features
Repository Contributions
35Total
Bugs
14
Commits
35
Features
12
Lines of code
1,158,783
Activity Months13
Your Network
696 peopleSame Organization
@apache.org683
a.huberMember
Akira AjisakaMember
Andrzej BiałeckiMember
Arturo BernalMember
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Attila BukorMember
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Abhishek ChennakaMember
Andreas DangelMember
Shared Repositories
13
Eric CovenerMember
Daniel FerradalMember
Giovanni BechisMember
Vincent DeffontainesMember
Christophe JailletMember
Jean-Frederic ClereMember
Joe OrtonMember
Lucien GentisMember
Graham LeggettMember
Work History
February 2026
3 Commits • 1 Features
Feb 1, 2026February 2026: Focused on stability, compatibility, and maintainability for apache/httpd. Delivered HTTP/2 stability upgrades and memory allocator deprecation to improve third-party module reliability, and fixed ARI-related ACME order behavior and APR compatibility to ensure robust ACME automation across versions. These changes reduce memory-related incidents, improve cross-version interoperability, and align with upstream modules.
3 Commits • 1 Features
Feb 1, 2026February 2026: Focused on stability, compatibility, and maintainability for apache/httpd. Delivered HTTP/2 stability upgrades and memory allocator deprecation to improve third-party module reliability, and fixed ARI-related ACME order behavior and APR compatibility to ensure robust ACME automation across versions. These changes reduce memory-related incidents, improve cross-version interoperability, and align with upstream modules.
February 2026
December 2025
3 Commits • 1 Features
Dec 1, 2025December 2025 — Apache httpd: Key features delivered, major fixes, and impact focused on reliability, configuration correctness, and memory safety in core modules (mod_md and mod_http2).
December 2025
3 Commits • 1 Features
Dec 1, 2025December 2025 — Apache httpd: Key features delivered, major fixes, and impact focused on reliability, configuration correctness, and memory safety in core modules (mod_md and mod_http2).
November 2025
4 Commits • 2 Features
Nov 1, 2025November 2025 — Apache httpd: Focused on delivering security, stability, and performance improvements through targeted feature updates and memory/HTTP handling fixes. Key features delivered include Mod_md certificate management enhancements (v2.6.5) with a new initial certificate check delay directive and strengthened renewal security, and HTTP/2 header processing improvements that leverage nghttp2-provided trailer lengths and a refactor of header-name comparisons for accuracy and speed. Major bug fix addressed a memory leak in OpenSSL BIGNUMs and improved curl handle reuse in the Mod_md workflow (v2.6.6). Impact: higher security posture for TLS certificate lifecycle, reduced memory footprint and resource churn, and faster, more reliable HTTP/2 header processing under load. Technologies demonstrated: TLS/certificate automation (mod_md), OpenSSL memory management, curl handle lifecycle, nghttp2 integration, and performance-focused C refactoring (ap_cstr_casecmpn).
4 Commits • 2 Features
Nov 1, 2025November 2025 — Apache httpd: Focused on delivering security, stability, and performance improvements through targeted feature updates and memory/HTTP handling fixes. Key features delivered include Mod_md certificate management enhancements (v2.6.5) with a new initial certificate check delay directive and strengthened renewal security, and HTTP/2 header processing improvements that leverage nghttp2-provided trailer lengths and a refactor of header-name comparisons for accuracy and speed. Major bug fix addressed a memory leak in OpenSSL BIGNUMs and improved curl handle reuse in the Mod_md workflow (v2.6.6). Impact: higher security posture for TLS certificate lifecycle, reduced memory footprint and resource churn, and faster, more reliable HTTP/2 header processing under load. Technologies demonstrated: TLS/certificate automation (mod_md), OpenSSL memory management, curl handle lifecycle, nghttp2 integration, and performance-focused C refactoring (ap_cstr_casecmpn).
November 2025
September 2025
1 Commits
Sep 1, 2025Month: 2025-09 — Apache httpd (mod_md) monthly review focused on robustness and compatibility improvements in string handling, plus targeted bug fix and alignment with the mod_md GitHub repository.
September 2025
1 Commits
Sep 1, 2025Month: 2025-09 — Apache httpd (mod_md) monthly review focused on robustness and compatibility improvements in string handling, plus targeted bug fix and alignment with the mod_md GitHub repository.
August 2025
6 Commits • 3 Features
Aug 1, 2025August 2025 performance overview for apache/httpd: Delivered robust HTTP/2 error handling enhancements, advanced mod_md 2.6.x renewal features (ACME ARI support, adjusted retry logic, and Tailscale removal), improved build/documentation traceability, and completed critical bug fixes. These changes improve reliability, reduce renewal traffic bursts, and streamline release processes.
6 Commits • 3 Features
Aug 1, 2025August 2025 performance overview for apache/httpd: Delivered robust HTTP/2 error handling enhancements, advanced mod_md 2.6.x renewal features (ACME ARI support, adjusted retry logic, and Tailscale removal), improved build/documentation traceability, and completed critical bug fixes. These changes improve reliability, reduce renewal traffic bursts, and streamline release processes.
August 2025
July 2025
1 Commits
Jul 1, 2025July 2025: Focused bug fix in HTTP/2 log2 calculations across httpd's HTTP/2 modules to stabilize push diaries and proxy window sizing. Implemented unsigned integer handling in log2 paths to prevent incorrect sizing, improving reliability of HTTP/2 proxying and push operations.
July 2025
1 Commits
Jul 1, 2025July 2025: Focused bug fix in HTTP/2 log2 calculations across httpd's HTTP/2 modules to stabilize push diaries and proxy window sizing. Implemented unsigned integer handling in log2 paths to prevent incorrect sizing, improving reliability of HTTP/2 proxying and push operations.
June 2025
1 Commits
Jun 1, 2025June 2025 — Apache httpd (mod_md) documentation fix delivered. Key features delivered: Documentation restoration of the MDActivationDelay directive in mod_md to fill a gap in user-facing configuration guidance. Major bugs fixed: Restored the MDActivationDelay directive documentation to address missing guidance. Overall impact and accomplishments: Improves configuration reliability for mod_md users, reduces ambiguity, and supports smoother adoption; maintains alignment with module capabilities and documentation standards. Technologies/skills demonstrated: Git-based version control, focused documentation work, mod_md configuration semantics, Apache httpd module ecosystem, cross-repo documentation alignment.
1 Commits
Jun 1, 2025June 2025 — Apache httpd (mod_md) documentation fix delivered. Key features delivered: Documentation restoration of the MDActivationDelay directive in mod_md to fill a gap in user-facing configuration guidance. Major bugs fixed: Restored the MDActivationDelay directive documentation to address missing guidance. Overall impact and accomplishments: Improves configuration reliability for mod_md users, reduces ambiguity, and supports smoother adoption; maintains alignment with module capabilities and documentation standards. Technologies/skills demonstrated: Git-based version control, focused documentation work, mod_md configuration semantics, Apache httpd module ecosystem, cross-repo documentation alignment.
June 2025
May 2025
2 Commits
May 1, 2025May 2025 focused on stabilizing core HTTP and MD features for apache/httpd through targeted fixes that boost reliability, performance, and security. Key work includes correcting H2WindowSize handling and session/multiplexing logic for HTTP/2, and enhancing TLS-ALPN-01 challenge support and status output formatting in MD, with related version upgrades. These changes reduce risk of incorrect window sizing, improve multiplexing efficiency, support multiple MDPrivateKeys (EC and RSA), and fix status page clarity. Overall, the month delivered measurable improvements in connection throughput, TLS challenge reliability, and operator UX, enabling smoother deployments and fewer incidents.
May 2025
2 Commits
May 1, 2025May 2025 focused on stabilizing core HTTP and MD features for apache/httpd through targeted fixes that boost reliability, performance, and security. Key work includes correcting H2WindowSize handling and session/multiplexing logic for HTTP/2, and enhancing TLS-ALPN-01 challenge support and status output formatting in MD, with related version upgrades. These changes reduce risk of incorrect window sizing, improve multiplexing efficiency, support multiple MDPrivateKeys (EC and RSA), and fix status page clarity. Overall, the month delivered measurable improvements in connection throughput, TLS challenge reliability, and operator UX, enabling smoother deployments and fewer incidents.
March 2025
6 Commits • 1 Features
Mar 1, 2025March 2025 monthly summary for apache/httpd focusing on HTTP/2 features, reliability, and maintenance. Delivered key HTTP/2 robustness and configurability improvements via mod_md 2.0.30, including improved header handling, timeout behavior, and a new H2MaxHeaderBlockLen directive. Implemented HTTP/2 reliability fixes such as correct 304 handling from mod_cache, restoration of stable backend detection in mod_proxy_http2, and enhanced logging for HTTP/2 session errors. Completed maintenance tasks to increment the versioning counter and fix documentation typos to reflect mod_http2 2.0.30. These changes collectively improve performance, reliability, observability, and release accuracy, delivering tangible business value by reducing client hangs, stabilizing backend interactions, and improving deployability.
6 Commits • 1 Features
Mar 1, 2025March 2025 monthly summary for apache/httpd focusing on HTTP/2 features, reliability, and maintenance. Delivered key HTTP/2 robustness and configurability improvements via mod_md 2.0.30, including improved header handling, timeout behavior, and a new H2MaxHeaderBlockLen directive. Implemented HTTP/2 reliability fixes such as correct 304 handling from mod_cache, restoration of stable backend detection in mod_proxy_http2, and enhanced logging for HTTP/2 session errors. Completed maintenance tasks to increment the versioning counter and fix documentation typos to reflect mod_http2 2.0.30. These changes collectively improve performance, reliability, observability, and release accuracy, delivering tangible business value by reducing client hangs, stabilizing backend interactions, and improving deployability.
March 2025
February 2025
2 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for apache/httpd development focused on delivering observable improvements in security, reliability, and performance through targeted feature work and bug fixes. Implemented enhanced ACME-based certificate management via Mod_md and added robust per-request timing in HTTP/2 for better performance visibility.
February 2025
2 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for apache/httpd development focused on delivering observable improvements in security, reliability, and performance through targeted feature work and bug fixes. Implemented enhanced ACME-based certificate management via Mod_md and added robust per-request timing in HTTP/2 for better performance visibility.
January 2025
2 Commits • 1 Features
Jan 1, 2025January 2025 (apache/httpd): Implemented reliability enhancements for certificate issuance (mod_md) and stabilized HTTP/2 test behavior. This work improves domain verification resilience, observability during certificate orders, and test reliability across curl versions, lowering incident risk and accelerating debugging and deployments.
2 Commits • 1 Features
Jan 1, 2025January 2025 (apache/httpd): Implemented reliability enhancements for certificate issuance (mod_md) and stabilized HTTP/2 test behavior. This work improves domain verification resilience, observability during certificate orders, and test reliability across curl versions, lowering incident risk and accelerating debugging and deployments.
January 2025
December 2024
3 Commits • 1 Features
Dec 1, 2024December 2024 monthly summary for apache/httpd. Focused on stabilizing the test suite, delivering a quality Mod_md 2.4.29 release, and improving operational visibility. Achievements centered on reducing CI flakiness, ensuring robust HTTP-01 handling, and polishing server-status and OCSP logging.
December 2024
3 Commits • 1 Features
Dec 1, 2024December 2024 monthly summary for apache/httpd. Focused on stabilizing the test suite, delivering a quality Mod_md 2.4.29 release, and improving operational visibility. Achievements centered on reducing CI flakiness, ensuring robust HTTP-01 handling, and polishing server-status and OCSP logging.
November 2024
1 Commits
Nov 1, 2024Month: 2024-11 — Stabilized Mod_http2 behavior under reset scenarios in apache/httpd. Implemented a keepalive timeout fix for reset requests, adding logic to count failed RST'ed requests to ensure connections honor the keepalive timeout after an initial request failure. Included regression tests validating the fix. This work improves reliability of persistent connections and reduces dropped requests under reset traffic, contributing to better user experience in high-load scenarios.
1 Commits
Nov 1, 2024Month: 2024-11 — Stabilized Mod_http2 behavior under reset scenarios in apache/httpd. Implemented a keepalive timeout fix for reset requests, adding logic to count failed RST'ed requests to ensure connections honor the keepalive timeout after an initial request failure. Included regression tests validating the fix. This work improves reliability of persistent connections and reduces dropped requests under reset traffic, contributing to better user experience in high-load scenarios.
November 2024
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Quality Metrics
Correctness91.4%
Maintainability89.4%
Architecture88.6%
Performance84.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
Apache ConfigurationCMarkdownPythonTextXMLYAML
Technical Skills
ACME ProtocolACME protocolApache HTTP ServerApache HTTP Server Module DevelopmentApache HTTP Server module developmentApache configurationApache module developmentApache modulesAutomationBackend DevelopmentBug FixingC ProgrammingC programmingCachingCertificate Management
Repositories Contributed To
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