Analyzer epoll-wait-timers

# Name

epoll-wait-timers - Wait timers for epoll

This analyzer profiles the timeout parameter distribution of epoll_wait and epoll_pwait system calls. It captures the timeout values (in milliseconds) passed to these calls, revealing the application’s event loop timeout strategy. A timeout of -1 indicates blocking mode (wait indefinitely), 0 means non-blocking (return immediately), and positive values specify maximum wait time. This helps identify polling patterns: aggressive polling (frequent short timeouts) may waste CPU, while overly long timeouts may reduce responsiveness. Understanding these patterns enables optimization of event loop efficiency and resource utilization.

# Resource Category

CPU.

# Application Type & Technical Stack

• All

# 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 epoll-wait-timers -p PID

# trace a shell command directly
orxray analyzer run epoll-wait-timers -c SHELL_CMD

# PGID is the process group ID or any process's PID within the target process
# group.
orxray analyzer run epoll-wait-timers -p -PGID

# trace any processes started from the specified executable path.
orxray analyzer run epoll-wait-timers --exe /path/to/exe/file

# Tracing Multiple Processes

Supported.

# Output Formats

• Plain Texts

# Output Example

{
  "data": {
    "min": "0", "max": "100", "avg": "45",
    "distributions": {
      "0": 5, "1": 11, "2": 31, "4": 70, "8": 95,
      "16": 213, "32": 342, "64": 318, "128": 0, "256": 0
    },
    "total": "1660"
  },
  "kind": "epoll-wait-timers"
}

# Author

The OpenResty Inc. Team.

# Copyright

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