Analyzer lj-read-fgraph

# Name

lj-read-fgraph - Lua-Land Virtual File System Read/Sendfile Flame Graph

This analyzer profiles file read operations including sendfile in Lua-land code within OpenResty and Kong applications. It captures C-level stack traces during VFS read operations initiated from Lua code and counts operation frequency. The analyzer generates flame graphs showing Lua code paths performing file reads, helping identify read-intensive Lua operations and optimize file access in Lua applications.

# Resource Category

Disk I/O.

# Application Type & Technical Stack

• OpenResty
• Kong
• APISIX

# Command Line Syntax

The analyzer can be invoked directly on the command-line via the orxray utility from the openresty-xray-cli software package.

Alternatively, the analyzer can also be invoked manually or automatically on the web console UI of OpenResty XRay (like on the Advanced web page).

# PID is the target process PID.
orxray analyzer run lj-read-fgraph -p PID

# trace a shell command directly
orxray analyzer run lj-read-fgraph -c SHELL_CMD

# PGID is the process group ID or any process's PID within the target process
# group.
orxray analyzer run lj-read-fgraph -p -PGID

# trace any processes started from the specified executable path.
orxray analyzer run lj-read-fgraph --exe /path/to/exe/file

# Tracing Multiple Processes

Supported.

# Output Formats

• Flame Graphs

# Author

The OpenResty Inc. Team.

# Copyright

Copyright (C) by OpenResty Inc. All rights reserved.