You're building functions over the location of files in HDFS? Automated
configuration of instances?
Jeremy Kepner wrote:
When we remove functions, do we have any official guidance to our users who may
have built applications that use those functions?
Right now, the official position is that the Accumulo developers can remove
as they see fit. However, this provides no guidance to users as to what
they are suppose to do? As it stands, our guidance is that they have the
following choices:
(0) Diligently watch the Accumulo e-mail list and aggressively weigh in on
any vote to remove functions that may impact them.
(1) Find someone to modify the original source code of their applications,
build it, and *re-verify* the application. I emphasise the re-verify because
that is usually the most costly part of the process that often won't get
approved
by management.
(2) Don't upgrade Accumulo.
On Thu, Dec 11, 2014 at 10:03:56AM -0500, Christopher wrote:
Well, no, the database will start if we rely on instance.volumes, but we
may be unable to find files that have relative paths, if we incorrectly
assume /accumulo. Making it required is annoying if users don't have
relative paths.
--
Christopher L Tubbs II
http://gravatar.com/ctubbsii
On Thu, Dec 11, 2014 at 8:15 AM,<[email protected]> wrote:
How so? If someone upgrades from another version and is using a different
dir, doesn't specify it in the configuration, and we assume /accumulo, then
their database won't start. The other option, which may be safer than
making any assumptions, is to make instance.volumes a required parameter
with no defaults.
----- Original Message -----
From: "Christopher"<[email protected]>
To: "Accumulo Dev List"<[email protected]>
Sent: Wednesday, December 10, 2014 11:51:39 PM
Subject: Re: Planning for (eventual) removal of instance.dfs.{uri,dir}
The URI is probably reasonable, but the dir is potentially problematic if
you weren't using the default.
--
Christopher L Tubbs II
http://gravatar.com/ctubbsii
On Wed, Dec 10, 2014 at 10:03 PM, dlmarion<[email protected]> wrote:
Looks like VolumeConfiguration falls back to fs.defaultFS for the uri and
/accumulo for the dir. You could remove both properties and still keep
this
as the documented default behavior if instance.volumes is not specified.
<div>-------- Original message --------</div><div>From: Christopher<
[email protected]> </div><div>Date:12/10/2014 9:13 PM (GMT-05:00)
</div><div>To: Accumulo Dev List<[email protected]>
</div><div>Cc:</div><div>Subject: Re: Planning for (eventual) removal of
instance.dfs.{uri,dir}</div><div>
</div>My ACCUMULO-2589 branch in github (
https://github.com/ctubbsii/accumulo/tree/ACCUMULO-2589) does have a
commit
that drops a bunch of stuff (which may or may not be accepted as is for
2.0). The instance.dfs.{uri,dir} properties aren't so easy and require
more
planning, because it's not just removing a property... it's also dealing
with updating internal data by making relative paths absolute.
For what it's worth, I'm also looking at what changes if we drop Hadoop 1
support.
As for the validation of config, I think we do a sanity check on startup
already, which we can always extend. Doesn't solve this issue, though.
--
Christopher L Tubbs II
http://gravatar.com/ctubbsii
On Wed, Dec 10, 2014 at 8:59 PM, dlmarion<[email protected]> wrote:
We should schedule a bunch of deprecated things for removal in 2.0 to
ease
maintenance. Do we have a way to validate the site.xml and zookeeper
settings before startup and fail with appropriate error message.
<div>-------- Original message --------</div><div>From: Christopher<
[email protected]> </div><div>Date:12/10/2014 8:44 PM (GMT-05:00)
</div><div>To: Accumulo Dev List<[email protected]>
</div><div>Cc:</div><div>Subject: Planning for (eventual) removal of
instance.dfs.{uri,dir}</div><div>
</div>So,
instance.volumes replaces instance.dfs.uri and instance.dfs.dir in 1.6.
But, what's our long-term plan for these? I ask, because we still have
internal code that uses instance.dfs.uri to resolve relative paths.
Should we force these to be re-written at some point (maybe on upgrade
to
1.7)? Should we continue to support the deprecated properties
indefinitely
and continue the lazy re-write-on-compact? Do we transition by
requiring
instance.volumes to specify the volumes, and only use the old
properties
to
resolve relative paths?
My personal view is that we should provide an upgrade-prep/check tool
prior
to upgrade to 2.0, which checks and/or re-writes paths and verifies
that
instance.volumes is set.
Does anybody have a different opinion on this?
--
Christopher L Tubbs II
http://gravatar.com/ctubbsii
