Analyzer tcpdump-upstream-no-keepalive

# Name

tcpdump-upstream-no-keepalive - capture the packets that have no HTTP upstream ‘keepalive’ configuration

This analyzer identifies and captures network packets for upstream connections that lack HTTP keepalive configuration in NGINX-based applications. It monitors TCP connection patterns to detect upstream requests that establish new connections instead of reusing existing ones. The analyzer generates PCAP files showing connection establishment overhead, helping identify performance issues caused by missing keepalive settings. This is valuable for optimizing upstream connection management and reducing latency from repeated TCP handshakes.

# Resource Category

Network I/O.

# Application Type & Technical Stack

• OpenResty
• Nginx
• 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 tcpdump-upstream-no-keepalive -p PID

# trace a shell command directly
orxray analyzer run tcpdump-upstream-no-keepalive -c SHELL_CMD

# Tracing Multiple Processes

Not supported.

# Output Formats

• Plain Texts

# Output Example

{
  "flows": [
      {
          "up_retmote_addr": "10.1.2.4 443",
          "down_retmote_addr": "10.1.34.26 40418",
          "down_local_addr": "172.16.11.240 443",
          "up_local_addr": "172.16.11.240 43232",
          "method": "GET",
          "flow": "flow_0.pcap",
          "host": "test.com",
          "time": "1764835117075898",
          "desc": "Request end time: Thu, 04 Dec 2025 07:58:37 GMT\nDownstream local address: 172.16.11.240:443\nDownstream remote address: 10.1.34.26:40418\nUpstream local address: 172.16.11.240:43232\nUpstream remote address: 10.1.2.4:443\nHTTP request: 'GET https://test.com/rpc-server'",
          "uri": "/rpc-server",
          "scheme": "https"
      }
  ]
}

# Author

The OpenResty Inc. Team.

# Copyright

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