GitHub SSH suddenly disappeared, what happened?

On August 12, 2021, many GitHub users encountered an issue when using SSH access. They found that no matter how hard they tried, they were unable to connect to their repositories via SSH. This confused and upset users, who took to social media to ask why. After some investigation, GitHub finally confirmed that the issue was due to a glitch in the GitHub system.

SSH (Secure Shell) is an encryption protocol that allows users to securely connect to remote computers over a network. SSH is more secure than other network connections because users can use key authentication to access remote computers, eliminating the need to enter a password. SSH is a very common way for GitHub users to access repositories. So when SSH suddenly disappeared, it was a huge blow to many users.

In fact, this is not the first time this has happened. Back in January 2020, GitHub experienced a similar outage, when many users reported being unable to access repositories using SSH. At the time, GitHub officially released a statement saying it was due to an unrelated system issue and that it was successfully fixed a few hours later. However, this time the outage lasted longer, lasting about a day, causing many users' work to be seriously affected.

After the problem occurred, GitHub published a blog post detailing the cause of the failure. It is reported that the failure was caused by GitHub's server used to handle SSH connections storing a large number of unnecessary SSH host keys. These keys are cached from past SSH connections, but when a certain number of keys are cached, it can cause performance issues on the server. Eventually, the accumulation of these keys caused the server to crash and become unable to provide SSH access.

In a blog post, GitHub said they are taking steps to prevent similar issues from happening again. These include strengthening the cache cleaning mechanism, implementing more intelligent caching strategies, and providing more detailed monitoring and alarm systems, etc. In addition, GitHub also urges users to use HTTPS for access when possible, as this can avoid the impact caused by SSH failure.

In short, although this SSH failure has brought trouble to many users, it also reminds us that we must keep monitoring and maintaining the system at all times. For technology companies such as GitHub, helping users solve technical problems and ensuring system stability and reliability are important issues they must face and solve every day.

The above is the detailed content of GitHub SSH suddenly disappeared, what happened?. For more information, please follow other related articles on the PHP Chinese website!