How to fix error: RPC failed; HTTP 503 Service Unavailable in Git

First, verify if the Git hosting service is experiencing issues:

GitHub:
- Status page: https://www.githubstatus.com/
- Twitter: https://twitter.com/githubstatus

GitLab:
- Status page: https://status.gitlab.com/

Bitbucket:
- Status page: https://bitbucket.status.atlassian.com/

Azure DevOps:
- Status page: https://status.dev.azure.com/

If the status page shows an incident, wait for the service to be restored. You can subscribe to status updates to be notified when the issue is resolved.

HTTP 503 errors are usually temporary. Wait a few minutes and try again:

# Wait 2-5 minutes, then retry your command
git push origin main

# Or for fetch/pull
git fetch origin

If you're running automated scripts or CI/CD pipelines, implement retry logic with exponential backoff:

# Simple bash retry loop
for i in {1..5}; do
  git push origin main && break
  echo "Attempt $i failed, retrying in $((i * 30)) seconds..."
  sleep $((i * 30))
done

If HTTPS is failing due to server issues, SSH connections might still work as they often use different infrastructure:

# Change remote URL from HTTPS to SSH
git remote set-url origin [email protected]:username/repo.git

# Verify the change
git remote -v

# Now try your operation
git push origin main

For GitLab:

git remote set-url origin [email protected]:username/repo.git

For Bitbucket:

git remote set-url origin [email protected]:username/repo.git

Note: You'll need SSH keys set up for this to work. See the Git documentation for SSH key setup.

Some Git services return 503 errors when you've hit rate limits. Check if you're being rate limited:

For GitHub:

# Check your rate limit status (requires authentication)
curl -H "Authorization: token YOUR_TOKEN" https://api.github.com/rate_limit

If you're hitting rate limits:
- Reduce the frequency of automated operations
- Use authenticated requests (they have higher limits)
- Implement caching for frequently accessed data
- Consider using GitHub Apps for higher rate limits

For CI/CD systems:
- Ensure you're using service accounts with appropriate rate limits
- Cache dependencies and repositories between builds
- Use shallow clones to reduce data transfer

If you're cloning or fetching large repositories, the server might time out. Try reducing the data transfer:

# Use shallow clone with limited history
git clone --depth 1 https://github.com/username/repo.git

# For existing repos, fetch with depth limit
git fetch --depth 1 origin main

# Use single branch clone
git clone --single-branch --branch main https://github.com/username/repo.git

For pushing large changes:

# Push in smaller batches
git push origin main~10:main
git push origin main~5:main
git push origin main

Network issues between you and the server can sometimes manifest as 503 errors:

# Test basic connectivity
ping github.com
curl -I https://github.com

# Check if a proxy is configured that might be failing
git config --global --get http.proxy
git config --global --get https.proxy

# Temporarily unset proxy to test direct connection
git config --global --unset http.proxy
git config --global --unset https.proxy

If you're behind a corporate proxy or firewall, it might be blocking or rate-limiting Git traffic. Contact your network administrator.

If you're using a self-hosted Git server (GitLab, Gitea, Gogs, etc.):

# Check server logs
sudo journalctl -u gitlab-runsvdir -f  # For GitLab
sudo journalctl -u gitea -f             # For Gitea

# Check system resources
top -b -n 1 | head -20
df -h  # Check disk space
free -m  # Check memory

# Restart the Git service if needed
sudo gitlab-ctl restart  # For GitLab
sudo systemctl restart gitea  # For Gitea

Common issues with self-hosted servers:
- Disk space full (especially for Git objects)
- Memory exhaustion
- Database connection issues
- Too many concurrent connections

If one remote is unavailable, you might be able to push to a mirror:

# Add a secondary remote as backup
git remote add backup [email protected]:username/repo.git

# Push to backup when primary is down
git push backup main

# Later, sync the mirrors when primary is back up
git push origin main

For read operations, you can also clone from mirrors:

# Many popular repositories have mirrors
# Check if a mirror exists for the repository you need