Resolving Git Push 'Remote End Hung Up Unexpectedly': Transitioning from HTTPS to SSH Protocol

Problem Background and Error Analysis

In daily usage of Git version control system, developers frequently encounter issues with unexpected disconnections from remote repositories. Specifically, when executing git push commands, the system returns "fatal: The remote end hung up unexpectedly" error messages. This error is often accompanied by RPC failures and specific HTTP status codes, such as the HTTP 413 error mentioned in the problem description.

The HTTP 413 status code indicates that the request entity is too large and the server refuses to process it. In the context of Git, this typically means the pushed data packet size exceeds the server's configuration limits. When using HTTPS protocol for Git operations, the default buffer size may be insufficient to handle large repositories or commits containing numerous files.

Impact of Protocol Selection on Git Operations

Git supports multiple protocols for communicating with remote repositories, with HTTPS and SSH being the most commonly used. The advantage of HTTPS protocol lies in its simple configuration, requiring no additional key management, but it has significant limitations when handling large data transfers.

SSH protocol employs encrypted end-to-end connections, independent of HTTP's request-response model, making it more stable for large file transfers. Once an SSH connection is established, data transmission occurs through a persistent encrypted channel, avoiding potential buffer overflow and connection timeout issues inherent in HTTP protocol.

Complete Steps for Switching from HTTPS to SSH

To switch an existing HTTPS remote repository to SSH protocol, follow these steps:

First, check the current remote repository configuration:

git remote -v

This displays the currently configured remote repository URLs. If it shows HTTPS format URLs (like https://github.com/username/repository.git), you need to change them to SSH format.

Remove the existing remote repository configuration:

git remote remove origin

Add the remote repository using SSH protocol:

git remote add origin git@github.com:username/repository.git

Verify the configuration changes:

git remote -v

This should now display the remote repository URL in SSH format.

SSH Key Configuration and Management

The prerequisite for successfully switching to SSH protocol is proper SSH key configuration. Here's the complete workflow for generating and configuring SSH keys:

Generate a new SSH key pair:

ssh-keygen -t ed25519 -C "your_email@example.com"

Start the SSH agent:

eval "$(ssh-agent -s)"

Add the SSH private key to the agent:

ssh-add ~/.ssh/id_ed25519

Copy the public key content to clipboard:

cat ~/.ssh/id_ed25519.pub

Finally, add the public key to the SSH key settings in GitHub or other Git hosting services.

Supplementary Solutions with Buffer Settings

In some cases, even after switching to SSH protocol, buffer settings adjustments might still be necessary. For exceptionally large repositories, you can configure SSH buffer size:

git config --global ssh.postBuffer 524288000

This command sets the SSH buffer size to 500MB, sufficient for handling most large file transfer requirements.

Error Diagnosis and Troubleshooting

When encountering connection issues, use the following methods for diagnosis:

Test SSH connection:

ssh -T git@github.com

Check network connection stability:

ping github.com

View detailed Git operation logs:

GIT_TRACE=1 git push origin master

Practical Recommendations for Protocol Selection

In actual development, it's recommended to choose the appropriate protocol based on project requirements:

For personal projects and small teams, SSH protocol offers better security and stability. For automated processes in enterprise environments, combining HTTPS with personal access tokens might be necessary. In CI/CD pipelines, select the most suitable protocol based on specific security requirements and network environment.

Regardless of the chosen protocol, regularly checking remote repository configurations and network connection status are important practices for maintaining Git workflow stability.