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https://issues.apache.org/jira/browse/HBASE-18226?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16053050#comment-16053050
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Ted Yu commented on HBASE-18226:
--------------------------------
{code}
+ When set to true, regionserver will use the current node hostname for the
servername and HMaster will skip reverse DNS lookup and use the hostname sent
by regionserver.
{code}
Wrapping long line would make the description more readable.
Adding little more background in the above paragraph (mentioning /etc/hosts
e.g.) would allow people to understand better.
{code}
+ <name>hbase.regionserver.hostname.auto</name>
{code}
Can you come up with better name ?
When reverse DNS is enabled, resolution is also automatic.
How about hbase.regionserver.hostname.from.etc.hosts ?
{code}
+ // use the hostname from regionserver node /etc/hosts,
hbase.regionserver.hostname will be
+ // overwritten if users specify it in hbase-site.xml.
{code}
Suggest throwing exception if both hbase.regionserver.hostname and the new
config are specified since they target different deployments.
Is it possible to add unit test ?
See if this gives you some clue: https://github.com/tdomzal/junit-docker-rule
> Disable reverse DNS lookup at HMaster and use default hostname provided by
> RegionServer
> ---------------------------------------------------------------------------------------
>
> Key: HBASE-18226
> URL: https://issues.apache.org/jira/browse/HBASE-18226
> Project: HBase
> Issue Type: Bug
> Reporter: Duo Xu
> Attachments: HBASE-18226.001.patch, HBASE-18226.002.patch
>
>
> This JIRA is to address the similar problem as HBASE-12954, but there are
> some little differences,
> 1. HBASE-12954 provides the configuration "hbase.regionserver.hostname" so
> users can configure it on every regionserver with preferred hostnames.
> However, this configuration cannot be set through Ambari or other
> configuration management tools because each regionserver has a different
> value of this setting, which means each node needs a different hbase-site.xml.
> 2. In Azure HDInsight clusters, we want to give each RegionServer/workernode
> a FQDN by modifying /etc/hosts on that node. We do not want HMaster to do
> reverse DNS lookup because HMaster VM's /etc/hosts does not have regionserver
> VM's FQDN mappings. In current implementation when regionserver starts,
> {code}
> String hostName = shouldUseThisHostnameInstead() ? useThisHostnameInstead :
> rpcServices.isa.getHostName();
> {code}
> it uses FQDN names here but on HMaster side, it will do reverse DNS lookup
> which cannot be resolved.
> {code}
> // if regionserver passed hostname to use,
> // then use it instead of doing a reverse DNS lookup
> ServerName rs = master.getServerManager().regionServerStartup(request, ia);
> {code}
> My proposed fix is to add a new configuration
> "*hbase.regionserver.hostname.auto*". If it is set to true, then Regionserver
> will use the value returned by *rpcServices.isa.getHostName()* as the
> hostname overwriting whatever users specifies in
> "*hbase.regionserver.hostname*" and send to HMaster as part of
> RegionServerStartupRequest. HMaster will not do reverse DNS lookup, which has
> been implemented in HBASE-12954. If users want to provide their own hostnames
> in "*hbase.regionserver.hostname*", "*hbase.regionserver.hostname.auto*" must
> be false.
> I will submit a patch later today.
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