Simple TCP proxy simulating delays in network

This simple proxy allows one to simulate different delays between different network nodes. Basic useful feature list:

• Intuitive YAML based configuration.
• Supports HTTP, HTTPS, and SQL Proxying.
• Allows delaying (simulating) slow SQL servers.
• Supports any TCP based Database interfaces e.g.MySQL, Oracle(tm) .
• Dynamic changes in delay parameters via REST API.
• Uses Netty for IO handling.
• Uses WSO2 MSF4J for REST API publishing.
• High performance, Low memory footprint, low CPU and resource usage.
• Can run headless.

Why?

How many times have you come across situations when there are intermittent failures in your system?

E.g.

• Connection resets from the database server
• Pool Exhuast errors
• Unknown retries.

As a support agent, I faced situations where the system was misbehaving and the developer insisted that the application logic was correct. The next culprit is network slowness or dropped packets.

I created this tool to analyze/simulate the system behaviour from one node to another with a slow and faulty network. It helped me to provide insightful feedback to developers to improve software resiliency as well as strong advice to the customers to improve the infrastructure.

how to build

mvn clean install
mvn package

How to Run

The binaries are available at /modules/dist/target/delaying-proxy. You can copy entire content and distribute as you wish.

Go to "delaying-proxy" directory

Linux/Unix/OS-X

bin/proxy proxy-conf.yaml

Windows

bin\proxy.bat proxy-conf.yaml

YAML Configuration

Configurations are done with "proxy-conf.yaml".

proxies:
proxiesConfig:
  name: "My Sample Proxy"
  restApi:
      listenPort: 8090        # Port which REST API (MSF4J) listens(optional, default 8080)
      listenAddresses: "0.0.0.0"    # machine IP Addresses or Host names to listen (not supported)
  proxies:
      - name: "To WSO2 IS"    # Unique human readable name
        enable: true          # enable or disable this proxy
        type: TCP             # Proxy type, TCP or SQL
        in:                   # Inbound configuration
          port: 10080         # Inbound listening port
          host: localhost     # Inbound listening IP (currently all IPs)
        out:                  # Outbound configuration
          port: 80            # Remote port to be proxied
          host: www.google.lk # Remote host to be proxied
        delay:                # Delay configurations (only one delay set can be configured currently)
          match: all          # - Unused
          min: 10             # Minimum Delay in milliseconds
          avg: 30             # Average delay in milliseconds
          max: 130            # Maximum delay in milliseconds

The delay is randomized on average delay. However it will be in between min and max value.

REST API

Set min, max or average delay

http://<host>:<port>/configure/proxy/{index}/delay/{match}/<min|max|average>/{value}

e.g.

http://<host>:<port>/configure/proxy/0/delay/match/min/3

Sets the minimum delay 3 milliseconds for the proxy at index 0. ("match" term currently unused and can put any string.)