flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From zhangminglei <...@git.apache.org>
Subject [GitHub] flink issue #5449: [FLINK-8623] ConnectionUtilsTest.testReturnLocalHostAddre...
Date Mon, 12 Mar 2018 09:43:50 GMT
Github user zhangminglei commented on the issue:

    https://github.com/apache/flink/pull/5449
  
    Thank you for your response, @StephanEwen You are very correct. We would not connect JM
/ RM / ZK if we use ```getByName("localhost")``` . 
    
    I will give an example based I have known about this issue.
    
    We still can't believe ```getLocalHost()``` too much , as the file ```/etc/hosts``` once
change the mapping of host name to an IP. That will cause a problem after that. And we will
get different value( that you set the mapping including this value)
    
    Below is my machine about this file, and I can always get a correct stuff of ```ricezhang-pjhzf.vclound.com/10.199.203.242```
that works for my network if I do not set that manually. 
    
    ```
    127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
    ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    
    ```
    
    Once I modify that file like below though, I will always get an **incorrect** value, because
```192.168.1.1``` is a a fake address. and will cause some issue.
    
    ```
    127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
    ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    192.168.1.1 ricezhang-pjhzf.vclound.com
    
    ```
    
    As refers to this **instability** test, **I don't know if something dynamically modified
that file on Travis** ? Or something like that ? Even if not, we also CAN NOT rely on this
method to get a IP that can connect to. Once the ```Zookeeper``` records the incorrect IP
address, this will cause error. We can not get a correct IP to connect to what we want.
    
    I agree with retry or a better test ( I do not know at this moment ) approach, I will
study this issue in depth in these days.



---

Mime
View raw message