Due to the needs of the company's project business, the code needs to be deployed on four servers. After deploying the access, it is found that the front-end page occasionally reports 404 errors
1. Preliminary guess, there is something wrong with the load balancer. After preliminary investigation of operation and maintenance, there is no abnormality
2. The second guess is that it is a server problem. After querying each server, it is found that the services are all good, and then gradually shut down each server, and troubleshoot the faulty server. Finally, it is found that one cannot be accessed without log records, and other servers have normal log records.
3. Finally, log in to the problematic server to check, and find that the port number of the security group has not opened ports 80 and 443
4. Finally, after releasing the port number, I found that the log has been written in the access
Finally, the problem is perfectly solved