背景： 随着我Ruby on Rails 的版本升级，sidekiq的升级，我的redis已经不能很好的支持了，当我启动sidekiq时出现如下报错：
redis-client requires Redis 6+ with HELLO command available (redis://127.0.0.1:6379/0)
意味着我需要升级redis-server
1.可以先删除当前低版本的redis, 可以用这个命令：
sudo apt-get purge --auto-remove redis-server2. 跟着官网教程重新安装：https://redis.io/docs/install/install-redis/install-redis-on-linux/
正常情况就可以了，但是可能是我Ubuntu版本太老了，执行sudo apt-get update一直出现如下错误：
13 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: Debian Jenkins Packages binary/ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY xxxxxxxxxxxx
W: Failed to fetch https://pkg.jenkins.io/debian/binary/Release.gpg? The following signatures couldn't be verified because the public key is not available: NO_PUBKEY xxxxxxxxxx
W: Some index files failed to download. They have been ignored, or old ones used instead.
网上找到这个解决方式Unable to install Jenkins on Ubuntu 20.04 - Stack Overflow
可以解决
curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | tee /usr/share/keyrings/jenkins-keyring.asc