[
https://issues.apache.org/jira/browse/ACCUMULO-118?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13900917#comment-13900917
]
Josh Elser commented on ACCUMULO-118:
-------------------------------------
I was just testing this out. I tried to add a new volume to an existing 1.6
instance I had lying around.
I expected that each volume I specified in {{instance.volumes}} was the
"equivalent" of how multiple {{instance.dfs.uri}}+{{instance.dfs.dir}} would
have worked. In other words, I expected each element in {{instance.volumes}} to
be the base directory that Accumulo would write to. Instead, it actually wrote
to that volume + {{instance.dfs.dir}}.
This irks me for a few reasons:
# I must have the same base directory used in HDFS across all volumes (not the
end of the world, but I don't see any reason to impose that on our end).
# I expected {{instance.volumes}} to be a replacement to {{instance.dfs.dir}}
and {{instance.dfs.uri}}, but the new configuration still relies on the old
configuration.
Let me try to be crystal clear. I had an existing installation on machine1 in
{{/accumulo1.6}} in HDFS. I tried to add a second volume, stored on machine2,
in {{/accumulo1.6-newvolume}} (I already had an /accumulo1.6 from other testing
on machine2). I configured my {{instance.volumes}} value to
{{hdfs://machine1:8020/accumulo1.6,hdfs://machine2:8020/accumulo1.6-newvolume}}.
Sadly, when invoking {{bin/accumulo init --add-volumes}}, this failed on me
because it actually looked in {{hdfs://machine1:8020/accumulo1.6/accumulo}} and
{{hdfs://machine2:8020/accumulo1.6-newvolume/accumulo}}.
> accumulo could work across HDFS instances, which would help it to scale past
> a single namenode
> ----------------------------------------------------------------------------------------------
>
> Key: ACCUMULO-118
> URL: https://issues.apache.org/jira/browse/ACCUMULO-118
> Project: Accumulo
> Issue Type: Improvement
> Components: master, tserver
> Reporter: Eric Newton
> Assignee: Eric Newton
> Priority: Blocker
> Fix For: 1.6.0
>
> Attachments: ACCUMULO-118-01.txt, ACCUMULO-118-02.txt
>
> Original Estimate: 2,016h
> Remaining Estimate: 2,016h
>
> Consider using full path names to files, which would allow the servers to
> access the files on any HDFS file system.
> Work may exist elsewhere to run HDFS using a number of NameNode instances to
> break up the namespace.
> We may need a pluggable strategy to determine namespace for new files.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
