比如有5台服务器跑了5个node项目，然后前面使用nginx做负载均衡
比如项目访问量很大，然后增加了一些新的功能，项目需要升级 5台服务器逐个升级，怎么能保证在升级的过程中不会影响访问
例如 现在要升级A服务器上的node项目，但是A服务器上有许多请求 如果直接升级的话，请求可能就会没有响应，如果项目涉及到对数据库操作，可能会产生脏数据
我能想到的一种方案是 事先发公告 没有流量的时候再升级
我想请问还没有其它方案，在不影响用户请求的情况下对服务进行升级呢
PHP中文网2017-04-17 16:02:19
It’s just unresponsive (I guess the tcp connection is interrupted). It’s relatively simple. You can gracefully restart nginx when switching configurations. In this way, you can remove a backend-upgrade the backend-and add it back.
But "without affecting access" not only needs to solve this, you also need to make the old version of the front end and the new version of the server shareable.
Dirty data is another problem. You should not expect every request to end normally, and there should always be a mechanism to clean up dirty data (on-site or afterward).
大家讲道理2017-04-17 16:02:19
This is more convenient when your server supports smooth restart. Smooth restart may be implemented by yourself, or it may be provided by a framework or library.
天蓬老师2017-04-17 16:02:19
You are wrong to think so. Unless you deploy different projects on 5 machines, then the upgrade can only cause downtime. Otherwise, what else can you do? What you mean is to deploy the same project on 5 machines. Then when upgrading, you consider how to not affect the service. Your starting point should be here. Then there is a question here. How do you distribute a request to 5 machines? On the machine, just adjust it according to how you did it. At the low point, change the 5 machines to 4 machines, and then add them back after the upgrade is successful. If you are worried about not being able to respond during the upgrade process, then adjust the cache time. , there are 5 machines, there will be no cache. . .
大家讲道理2017-04-17 16:02:19
Upgrades are usually done early in the morning, because if something goes wrong, it won’t have such a big impact
高洛峰2017-04-17 16:02:19
Responsible for balancing and downgrading a server, upgrading it, and then upping it again
PHP中文网2017-04-17 16:02:19
It is impossible not to have any impact at all. The only way is to make the impact as invisible as possible. If you observe JD.com, you will find that its servers are often upgraded early in the morning. When upgrading, you cannot open its menu and nothing will appear. I kept watching and spinning around, but the content just didn’t come out. So basically when upgrading, the server is switched to a friendly interface that does not display content, and then switched back after the upgrade.
巴扎黑2017-04-17 16:02:19
Upgrade one server at a time, directing traffic to other servers during the upgrade process
天蓬老师2017-04-17 16:02:19
Our project uses pm2 for release and process management
Publishing will not affect users’ usage
