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https://issues.apache.org/jira/browse/HBASE-18226?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16056965#comment-16056965
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Ted Yu commented on HBASE-18226:
--------------------------------

TestMasterProcedureWalLease is flaky.

+1 from me.

> Disable reverse DNS lookup at HMaster and use the hostname provided by 
> RegionServer
> -----------------------------------------------------------------------------------
>
>                 Key: HBASE-18226
>                 URL: https://issues.apache.org/jira/browse/HBASE-18226
>             Project: HBase
>          Issue Type: Bug
>            Reporter: Duo Xu
>            Assignee: Duo Xu
>         Attachments: HBASE-18226.001.patch, HBASE-18226.002.patch, 
> HBASE-18226.003.patch, HBASE-18226.004.patch, HBASE-18226.005.patch, 
> HBASE-18226.006.patch
>
>
> Description updated:
> In some unusual network environment, forward DNS lookup is supported while 
> reverse DNS lookup may not work properly.
> This JIRA is to address that HMaster uses the hostname passed from RS instead 
> of doing reverse DNS lookup to tells RS which hostname to use during 
> reportForDuty() . This has already been implemented by HBASE-12954 by adding 
> "useThisHostnameInstead" field in RegionServerStatusProtos.
> Currently "useThisHostnameInstead" is optional and RS by default only passes 
> port, server start code and server current time info to HMaster during RS 
> reportForDuty(). In order to use this field, users currently need to specify 
> "hbase.regionserver.hostname" on every regionserver node's hbase-site.xml. 
> This causes some trouble in
> 1. some deployments managed by some management tools like Ambari, which 
> maintains the same copy of hbase-site.xml across all the nodes.
> 2. HBASE-12954 is targeting multihomed hosts, which users want to manually 
> set the hostname value for each node. In the other cases (not multihomed), I 
> just want RS to use the hostname return by the node and set it in 
> useThisHostnameInstead and pass to HMaster during reportForDuty().
> I would like to introduce a setting that if the setting is set to true, 
> "useThisHostnameInstead" will be set to the hostname RS gets from the node. 
> Then HMaster will skip reverse DNS lookup because it sees 
> "useThisHostnameInstead" field is set in the request.
> "hbase.regionserver.hostname.reported.to.master", is it a good name?
> --------------------
> Regarding the hostname returned by the RS node, I read the source code again 
> (including hadoop-common dns.java). By default RS gets hostname by calling 
> InetAddress.getLocalHost().getCanonicalHostName(). If users specify 
> "hbase.regionserver.dns.interface" or "hbase.regionserver.dns.nameserver" or 
> some underlying system configuration changes (eg. modifying 
> /etc/nsswitch.conf), it may first read from DNS or other sources instead of 
> first checking /etc/hosts file.



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