OpenResty XRay Jun 28, 2023

OpenResty XRay Updated Jun 28, 2023 11 mins read

Tracing the Slowest PCRE Regular Expressions in OpenResty or Nginx Processes

• System Environment
• Narrowing Down the Culprit without Guessing
• Limiting the execution overhead of PCRE
• Non-Backtracking Regular Expression Engines
• Lua’s Builtin Patterns
• Tracing Applications inside Containers
• How The Tools are Implemented
• The Overhead of the Tools

OpenResty XRay Apr 10, 2024

OpenResty XRay Updated Apr 10, 2024 9 mins read

Listing Loaded Lua Modules in OpenResty or Nginx Processes

• System Environment
• Names of Loaded Lua Modules
• Running Directly in the Web Console
• Tracing Applications inside Containers
• How The Tools are Implemented
• The Overhead of the Tools

OpenResty XRay Apr 10, 2024

OpenResty XRay Updated Apr 10, 2024 12 mins read

Analyzing the Most CPU-Consuming Requests in OpenResty or Nginx

• System Environment
• CPU-Hottest Request Hostnames
• CPU-Hottest Request URIs
• Digging Deeper
• Running Directly in the Web Console
• Tracing Applications inside Containers
• How The Tools are Implemented
• The Overhead of the Tools

OpenResty XRay Sep 20, 2023

OpenResty XRay Updated Sep 20, 2023 14 mins read

Ylang: Universal Language for eBPF, Stap+, GDB, and More (Part 4 of 4)

• Transparent Container Tracing
• Efficient Stack Unwinding
• Analyzing Dead Processes (Core Dumps)
• Very Low Tracing Overhead
• Standard Ylang Libraries & Tools
• Network Filtering & Control
• The Ylang Compiler’s Implementation
• Operating System Support
• Contributions to Open-Source Communities

OpenResty XRay Jul 10, 2023

OpenResty XRay Updated Jul 10, 2023 10 mins read

Ylang: Universal Language for eBPF, Stap+, GDB, and More (Part 3 of 4)

• The Language Syntax (Continued)
  • String Literals
  • Built-in Regex Support
  • Full Control-Flow Support
  • Floating-Point Number Support
  • Compared to Open-Source Toolchains
• Transparent Debug Symbol Handling
  • Debug Symbols: No Runtime Overhead
  • Centralized Package Database
  • Fuzzy Matching Debug Symbols

OpenResty XRay Aug 21, 2023

OpenResty XRay Updated Aug 21, 2023 14 mins read

Ylang: Universal Language for eBPF, Stap+, GDB, and More (Part 2 of 4)

• The Language Syntax (Continued)
  • Macros with Extensions
  • Tracer and Tracee Spaces
  • Probes
  • Extended Variable Types

OpenResty XRay Jul 10, 2023

OpenResty XRay Updated Jul 10, 2023 14 mins read

Ylang: Universal Language for eBPF, Stap+, GDB, and More (Part 1 of 4)

• What is Dynamic Tracing
• Why the “Y” Name
• Getting Started
• Various Backends and Runtimes
• Why a Unified Frontend Language
• The Language Syntax

OpenResty XRay Apr 10, 2024

OpenResty XRay Updated Apr 10, 2024 19 mins read

Introduction to Lua-Land CPU Flame Graphs

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

OpenResty XRay Jul 6, 2023

OpenResty XRay Updated Jul 6, 2023 10 mins read

Memory Fragmentation in OpenResty and Nginx's Shared Memory Zones

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

OpenResty XRay Jul 6, 2023

OpenResty XRay Updated Jul 6, 2023 13 mins read

How OpenResty and Nginx Shared Memory Zones Consume RAM

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

OpenResty XRay Apr 10, 2024

OpenResty XRay Updated Apr 10, 2024 11 mins read

How OpenResty and Nginx Allocate and Manage Memory

• On The System Level
• On The Application Level
• For Traditional Nginx Servers

OpenResty XRay Apr 10, 2024

OpenResty XRay Updated Apr 10, 2024 16 mins read

The LuaJIT GC64 Mode

• The Old Memory Limit
  • When Hitting The Memory Limit
  • The Memory Limit Is Per Process
  • GC-Managed Memory
  • Memory Allocated Outside GC
  • Extending The x64 Mode to The 4 GB Limit
• The New GC64 Mode
  • How to Enable The GC64 Mode
  • Performance Impact
  • Debugging and Profiling Tool Chains