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https://issues.apache.org/jira/browse/HBASE-12954?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14302622#comment-14302622
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Enis Soztutar commented on HBASE-12954:
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bq. You are not describing how it currently works – master tells the RS what to
use so no need of reverse lookup
The RS connects to master with it's ip. Master does a reverse lookup (no?), and
tells that to the region server its own hostname and RS uses it from then on.
At least that is what I understand from the current code.
What I am proposing is a slight alteration (which is similar to what the patch
has since I was involved in the initial discussions for the patch) that:
- we configure a hostname for the regionserver
- RS sends the configured hostname over the region server startup rpc.
- Master does not do a reverse DNS resolution, but instead uses the hostname
coming from the RPC parameters.
- Master does a forward resolution of the hostname to verify that it can talk
to the region server.
- The hostname (ServerName) is passed back to the RS, which uses it from then
on.
Again, correct me if I am wrong. I'll re-check the code.
> Ability impaired using HBase on multihomed hosts
> ------------------------------------------------
>
> Key: HBASE-12954
> URL: https://issues.apache.org/jira/browse/HBASE-12954
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.98.4
> Reporter: Clay B.
> Assignee: Ted Yu
> Priority: Minor
> Attachments: 12954-v1.txt, Hadoop Three Interfaces.png
>
>
> For HBase clusters running on unusual networks (such as NAT'd cloud
> environments or physical machines with multiple IP's per network interface)
> it would be ideal to have a way to both specify:
> # which IP interface to which HBase master or region-server will bind
> # what hostname HBase will advertise in Zookeeper both for a master or
> region-server process
> While efforts such as HBASE-8640 go a long way to normalize these two sources
> of information, it is not possible in the current design of the properties
> available to an administrator for these to be unambiguously specified.
> One has been able to request {{hbase.master.ipc.address}} or
> {{hbase.regionserver.ipc.address}} but one can not specify the desired HBase
> {{hbase.master.hostname}}. (It was removed in HBASE-1357, further I am
> unaware of a region-server equivalent.)
> I use a configuration management system to generate all of my configuration
> files on a per-machine basis. As such, an option to generate a file
> specifying exactly which hostname to use would be helpful.
> Today, specifying the bind address for HBase works and one can use an
> HBase-only DNS for faking what to put in Zookeeper but this is far from
> ideal. Network interfaces have no intrinsic IP address, nor hostname.
> Specifing a DNS server is awkward as the DNS server may differ from the
> system's resolver and is a single IP address. Similarly, on hosts which use a
> transient VIP (e.g. through keepalived) for other services, it means there's
> a seemingly non-deterministic hostname choice made by HBase depending on the
> state of the VIP at daemon start-up time.
> I will attach two networking examples I use which become very difficult to
> manage under the current properties.
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