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Hello World HTTP Example in OpenResty

November 14, 2020 3 mins read Posted by Yichun Zhang (updated Dec 20, 2021)

This tutorial demonstrates how to implement a “hello world” HTTP interface using OpenResty. First of all, we make sure we are using OpenResty’s nginx. Read more...

OpenResty 1.19.3.1 released

Nov 5, 2020 1 min read Posted by OpenResty Inc. (updated Jan 2, 2022)

We are happy to announce the new formal release, 1.19.3.1, of our OpenResty web platform based on NGINX and LuaJIT. The full announcement, download links, and change logs can be found below: Read more...

Introduction to Lua-Land CPU Flame Graphs

Aug 31, 2020 18 mins read Posted by Yichun Zhang (updated Jan 4, 2022)

What is a Flame Graph
Simple Lua samples
Complicated Lua applications
Sampling overhead
Safety
Compatibility
Other types of Lua-land Flame Graphs

Memory Fragmentation in OpenResty and Nginx's Shared Memory Zones

Aug 10, 2020 9 mins read Posted by Yichun Zhang (updated Jan 2, 2022)

An empty zone
Filling entries of similar sizes
Deleting odd-numbered keys
Deleting the keys in the first half
Mitigating Fragmentation

How OpenResty and Nginx Shared Memory Zones Consume RAM

Aug 4, 2020 13 mins read Posted by Yichun Zhang (updated Jan 4, 2022)

Slabs and pages
What is allocated is not what is paid for
Fake Memory Leaks
HUP reload

OpenResty 1.17.8.1 released

Jul 8, 2020 2 mins read Posted by Vivian Liu (updated Jan 2, 2022)

OpenResty 1.17.8.1 released
Full Changelog
The Next Release

The Wonderland of Dynamic Tracing (Part 4 of 7)

Jun 27, 2020 7 mins read Posted by Yichun Zhang (updated Dec 20, 2021)

This is Part 4 of the series “The Wonderland of Dynamic Tracing” which consists of 7 parts. I will keep updating this series to reflect the state of art of the dynamic tracing world. Read more...

The Wonderland of Dynamic Tracing (Part 3 of 7)

Jun 26, 2020 11 mins read Posted by Yichun Zhang (updated Jan 2, 2022)

Applications of SystemTap in Production
- Case #1: Slow Debugging Code Left in Production
- Case #2: Long request latency outliers
- Case #3: From Network Issues to Disk Issues
- Case #4: File Handle Cache Tradeoffs
- Case #5: Compiled Regex Cache Tuning