[
https://issues.apache.org/jira/browse/HADOOP-7104?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12982069#action_12982069
]
Jakob Homan commented on HADOOP-7104:
-------------------------------------
As Nigel detailed in his recent email, only critical or blocker bugs should be
applied to the 22 branch, and only with strong justification. This issue is
correctly categorized as an improvement. Therefore, it's up to Nigel as RM to
pull in the patch to 22 if he wishes.
> Remove unnecessary DNS reverse lookups from RPC layer
> -----------------------------------------------------
>
> Key: HADOOP-7104
> URL: https://issues.apache.org/jira/browse/HADOOP-7104
> Project: Hadoop Common
> Issue Type: Improvement
> Components: ipc, security
> Reporter: Kan Zhang
> Assignee: Kan Zhang
> Fix For: 0.23.0
>
> Attachments: 7104-few-edits.patch, c7104-01.patch, c7104-03.patch
>
>
> RPC connection authorization needs to verify client's Kerberos principal name
> matches what specified for the protocol. For service clients like DN's, their
> Kerberos principal names can be specified in the form of
> "datanode/[email protected]". To get the expected
> client principal name, the server needs to substitute "_HOST" with the
> client's fully qualified domain name, which requires a reverse DNS lookup
> from client IP address. However, for connections from clients whose principal
> name are either unspecified or specified not using the "_HOST" convention,
> the substitution is not required and the reverse DNS lookup should be
> avoided. Currently the reverse DNS lookup is done for all clients, which
> could slow services like NN down, when local named cache is not available.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
