*. Once in the test, it was found that the database could not be connected, and then various detection ports, access, monitoring, etc. were normal.
lsnrctl status can be opened, but super slow
If I followed the above operations earlier, I would have found the problem earlier, because I have been doing the following things:
netstat -ano | findStr 1521 can print normal monitoring
Although there are abnormal phenomena such as fin_wait and close_wait abnormality in monitoring and printing, but this is not the root cause, hey.
*, So inadvertently in the query "listening is connecting but super slow" found the following scheme
The log file is too large, resulting in very, very slow monitoring, so I renamed the file, and found that it was really cool to have no friends, and lsnrctl status killed it in seconds. Source: http://blog.51cto.com/12185273/2084674 Thank you very much, ahaha, but the hard part is why I just met it, just met it today? It stands to reason that other project teams should also be using it. ╮(╯▽╰)╭