SSH Connection Issues with Orange Pi 5 Pro Running Resource-Intensive Program

Introduction

This article aims to provide a solution to SSH connection issues that may occur on an Orange Pi 5 Pro running Ubuntu 22 server with a resource-intensive program. The Orange Pi 5 Pro is a powerful single-board computer with eight cores, but even with a short runtime for the program, consistent connection issues may arise.

Symptoms

The symptoms of SSH connection issues on the Orange Pi 5 Pro include:

• Connection timeouts
• Connection refusals
• Connection drops

Possible Causes

There are several possible causes for SSH connection issues on the Orange Pi 5 Pro:

1. Memory Pressure

   When running a resource-intensive program, the Orange Pi 5 Pro may experience memory pressure, leading to SSH connection issues. The SSH daemon may be terminated to free up memory for other processes.

2. CPU Overload

   A resource-intensive program may also cause the CPU to become overloaded, leading to SSH connection issues. The SSH daemon may not be able to respond to incoming connections due to the high CPU usage.

3. Firewall Rules

   Firewall rules may also be causing SSH connection issues. The rules may be blocking incoming SSH connections or restricting access to specific IP addresses.

Solutions

To resolve SSH connection issues on the Orange Pi 5 Pro, consider the following solutions:

Adjust SSH Config

You can adjust the SSH config file to increase the connection timeout and other settings. Here's how:

 sudo nano /etc/ssh/ssh_config
 # Increase connection timeout
 Host *
 ConnectionTimeout 120
 # Increase TCP keepalive interval
 Host *
 TCPKeepAlive yes
 TCPKeepAliveInterval 300
 
 

Allocate More Memory

You can allocate more memory to the SSH daemon to prevent memory pressure. Here's how:

 sudo nano /etc/systemd/system/ssh.service
 # Add the following lines to the [Service] section
 MemoryLimit=128M
 MemorySwapLimit=128M
 
 

Limit CPU Usage

You can limit the CPU usage of the resource-intensive program to prevent CPU overload. Here's how:

 # Add the following lines to the program's start script
 nice -n 19 /path/to/program.sh
 
 

Adjust Firewall Rules

You can adjust the firewall rules to allow incoming SSH connections. Here's how:

 sudo ufw allow OpenSSH