[Gluster-Maintainers] [Gluster-users] Proposal to mark few features as Deprecated / SunSet from Version 5.0
Jim Kinney
jim.kinney at gmail.com
Tue Mar 19 21:20:57 UTC 2019
Volume Name: home
Type: Replicate
Volume ID: 5367adb1-99fc-44c3-98c4-71f7a41e628a
Status: Started
Snapshot Count: 0
Number of Bricks: 1 x 2 = 2
Transport-type: tcp,rdma
Bricks:
Brick1: bmidata1:/data/glusterfs/home/brick/brick
Brick2: bmidata2:/data/glusterfs/home/brick/brick
Options Reconfigured:
performance.client-io-threads: off
storage.build-pgfid: on
cluster.self-heal-daemon: enable
performance.readdir-ahead: off
nfs.disable: off
There are 11 other volumes and all are similar.
On Tue, 2019-03-19 at 13:59 -0700, Vijay Bellur wrote:
> Thank you for the reproducer! Can you please let us know the output
> of `gluster volume info`?
> Regards,
> Vijay
>
> On Tue, Mar 19, 2019 at 12:53 PM Jim Kinney <jim.kinney at gmail.com>
> wrote:
> > This python will fail when writing to a file in a glusterfs fuse
> > mounted directory.
> >
> > import mmap
> >
> > # write a simple example file
> > with open("hello.txt", "wb") as f:
> > f.write("Hello Python!\n")
> >
> > with open("hello.txt", "r+b") as f:
> > # memory-map the file, size 0 means whole file
> > mm = mmap.mmap(f.fileno(), 0)
> > # read content via standard file methods
> > print mm.readline() # prints "Hello Python!"
> > # read content via slice notation
> > print mm[:5] # prints "Hello"
> > # update content using slice notation;
> > # note that new content must have same size
> > mm[6:] = " world!\n"
> > # ... and read again using standard file methods
> > mm.seek(0)
> > print mm.readline() # prints "Hello world!"
> > # close the map
> > mm.close()
> >
> >
> >
> >
> >
> >
> >
> >
> > On Tue, 2019-03-19 at 12:06 -0400, Jim Kinney wrote:
> > > Native mount issue with multiple clients (centos7 glusterfs
> > > 3.12).
> > > Seems to hit python 2.7 and 3+. User tries to open file(s) for
> > > write on long process and system eventually times out.
> > > Switching to NFS stops the error.
> > > No bug notice yet. Too many pans on the fire :-(
> > > On Tue, 2019-03-19 at 18:42 +0530, Amar Tumballi Suryanarayan
> > > wrote:
> > > > Hi Jim,
> > > >
> > > > On Tue, Mar 19, 2019 at 6:21 PM Jim Kinney <
> > > > jim.kinney at gmail.com> wrote:
> > > > >
> > > > >
> > > > >
> > > > > Issues with glusterfs fuse mounts cause issues with python
> > > > > file open for write. We have to use nfs to avoid this.
> > > > >
> > > > > Really want to see better back-end tools to facilitate
> > > > > cleaning up of glusterfs failures. If system is going to use
> > > > > hard linked ID, need a mapping of id to file to fix things.
> > > > > That option is now on for all exports. It should be the
> > > > > default If a host is down and users delete files by the
> > > > > thousands, gluster _never_ catches up. Finding path names for
> > > > > ids across even a 40TB mount, much less the 200+TB one, is a
> > > > > slow process. A network outage of 2 minutes and one system
> > > > > didn't get the call to recursively delete several dozen
> > > > > directories each with several thousand files.
> > > > >
> > > > >
> > > >
> > > > Are you talking about some issues in geo-replication module or
> > > > some other application using native mount? Happy to take the
> > > > discussion forward about these issues.
> > > > Are there any bugs open on this?
> > > > Thanks,Amar
> > > > > nfsOn March 19, 2019 8:09:01 AM EDT, Hans Henrik Happe <
> > > > > happe at nbi.dk> wrote:
> > > > > > Hi,
> > > > > > Looking into something else I fell over this proposal.
> > > > > > Being a
> > > > > > shop that are going into "Leaving GlusterFS" mode, I
> > > > > > thought I
> > > > > > would give my two cents.
> > > > > >
> > > > > >
> > > > > > While being partially an HPC shop with a few Lustre
> > > > > > filesystems,
> > > > > > we chose GlusterFS for an archiving solution (2-3
> > > > > > PB), because we
> > > > > > could find files in the underlying ZFS filesystems if
> > > > > > GlusterFS
> > > > > > went sour.
> > > > > > We have used the access to the underlying files plenty,
> > > > > > because
> > > > > > of the continuous instability of GlusterFS'.
> > > > > > Meanwhile, Lustre
> > > > > > have been almost effortless to run and mainly for
> > > > > > that reason we
> > > > > > are planning to move away from GlusterFS.
> > > > > > Reading this proposal kind of underlined that "Leaving
> > > > > > GluserFS"
> > > > > > is the right thing to do. While I never understood
> > > > > > why GlusterFS
> > > > > > has been in feature crazy mode instead of stabilizing
> > > > > > mode, taking
> > > > > > away crucial features I don't get. With RoCE, RDMA is
> > > > > > getting
> > > > > > mainstream. Quotas are very useful, even though the
> > > > > > current
> > > > > > implementation are not perfect. Tiering also makes so
> > > > > > much sense,
> > > > > > but, for large files, not on a per-file level.
> > > > > > To be honest we only use quotas. We got scared of
> > > > > > trying out new
> > > > > > performance features that potentially would open up a
> > > > > > new back of
> > > > > > issues.
> > > > > > Sorry for being such a buzzkill. I really wanted it to
> > > > > > be
> > > > > > different.
> > > > > >
> > > > > >
> > > > > > Cheers,
> > > > > >
> > > > > > Hans Henrik
> > > > > >
> > > > > >
> > > > > > On 19/07/2018 08.56, Amar Tumballi
> > > > > > wrote:
> > > > > >
> > > > > >
> > > > > >
> > > > > > >
> > > > > > >
> > > > > > > Hi all,
> > > > > > > Over last 12 years of Gluster, we have
> > > > > > > developed many features, and continue to support most of
> > > > > > > it till now. But along the way, we have figured out
> > > > > > > better methods of doing things. Also we are not actively
> > > > > > > maintaining some of these features.
> > > > > > > We are now thinking of cleaning up some of
> > > > > > > these ‘unsupported’ features, and mark them as ‘SunSet’
> > > > > > > (i.e., would be totally taken out of codebase in
> > > > > > > following releases) in next upcoming release, v5.0. The
> > > > > > > release notes will provide options for smoothly migrating
> > > > > > > to the supported configurations.
> > > > > > > If you are using any of these features, do let
> > > > > > > us know, so that we can help you with ‘migration’.. Also,
> > > > > > > we are happy to guide new developers to work on those
> > > > > > > components which are not actively being maintained by
> > > > > > > current set of developers.
> > > > > > > List of features hitting sunset:
> > > > > > > ‘cluster/stripe’ translator:
> > > > > > > This translator was developed very early in the
> > > > > > > evolution of GlusterFS, and addressed one of the very
> > > > > > > common question of Distributed FS, which is “What happens
> > > > > > > if one of my file is bigger than the available brick.
> > > > > > > Say, I have 2 TB hard drive, exported in glusterfs, my
> > > > > > > file is 3 TB”. While it solved the purpose, it was very
> > > > > > > hard to handle failure scenarios, and give a real good
> > > > > > > experience to our users with this feature. Over the time,
> > > > > > > Gluster solved the problem with it’s ‘Shard’ feature,
> > > > > > > which solves the problem in much better way, and provides
> > > > > > > much better solution with existing well supported stack.
> > > > > > > Hence the proposal for Deprecation.
> > > > > > > If you are using this feature, then do write to
> > > > > > > us, as it needs a proper migration from existing volume
> > > > > > > to a new full supported volume type before you upgrade.
> > > > > > > ‘storage/bd’ translator:
> > > > > > > This feature got into the code base 5 years
> > > > > > > back with this patch[1]. Plan was to use a block device
> > > > > > > directly as a brick, which would help to handle disk-
> > > > > > > image storage much easily in glusterfs.
> > > > > > > As the feature is not getting more
> > > > > > > contribution, and we are not seeing any user traction on
> > > > > > > this, would like to propose for Deprecation.
> > > > > > > If you are using the feature, plan to move to a
> > > > > > > supported gluster volume configuration, and have your
> > > > > > > setup ‘supported’ before upgrading to your new gluster
> > > > > > > version.
> > > > > > > ‘RDMA’ transport support:
> > > > > > > Gluster started supporting RDMA while ib-verbs
> > > > > > > was still new, and very high-end infra around that time
> > > > > > > were using Infiniband. Engineers did work with Mellanox,
> > > > > > > and got the technology into GlusterFS for better data
> > > > > > > migration, data copy. While current day kernels support
> > > > > > > very good speed with IPoIB module itself, and there are
> > > > > > > no more bandwidth for experts in these area to maintain
> > > > > > > the feature, we recommend migrating over to TCP (IP
> > > > > > > based) network for your volume.
> > > > > > > If you are successfully using RDMA transport,
> > > > > > > do get in touch with us to prioritize the migration plan
> > > > > > > for your volume. Plan is to work on this after the
> > > > > > > release, so by version 6.0, we will have a cleaner
> > > > > > > transport code, which just needs to support one type.
> > > > > > > ‘Tiering’ feature
> > > > > > > Gluster’s tiering feature which was planned to
> > > > > > > be providing an option to keep your ‘hot’ data in
> > > > > > > different location than your cold data, so one can get
> > > > > > > better performance. While we saw some users for the
> > > > > > > feature, it needs much more attention to be completely
> > > > > > > bug free. At the time, we are not having any active
> > > > > > > maintainers for the feature, and hence suggesting to take
> > > > > > > it out of the ‘supported’ tag.
> > > > > > > If you are willing to take it up, and maintain
> > > > > > > it, do let us know, and we are happy to assist you.
> > > > > > > If you are already using tiering feature,
> > > > > > > before upgrading, make sure to do gluster volume tier
> > > > > > > detach all the bricks before upgrading to next release.
> > > > > > > Also, we recommend you to use features like dmcache on
> > > > > > > your LVM setup to get best performance from bricks.
> > > > > > > ‘Quota’
> > > > > > > This is a call out for ‘Quota’ feature, to let
> > > > > > > you all know that it will be ‘no new development’ state.
> > > > > > > While this feature is ‘actively’ in use by many people,
> > > > > > > the challenges we have in accounting mechanisms involved,
> > > > > > > has made it hard to achieve good performance with the
> > > > > > > feature. Also, the amount of extended attribute get/set
> > > > > > > operations while using the feature is not very ideal.
> > > > > > > Hence we recommend our users to move towards setting
> > > > > > > quota on backend bricks directly (ie, XFS project quota),
> > > > > > > or to use different volumes for different directories
> > > > > > > etc.
> > > > > > > As the feature wouldn’t be deprecated
> > > > > > > immediately, the feature doesn’t need a migration plan
> > > > > > > when you upgrade to newer version, but if you are a new
> > > > > > > user, we wouldn’t recommend setting quota feature. By the
> > > > > > > release dates, we will be publishing our best
> > > > > > > alternatives guide for gluster’s current quota feature.
> > > > > > > Note that if you want to contribute to the
> > > > > > > feature, we have project quota based issue open[2] Happy
> > > > > > > to get contributions, and help in getting a newer
> > > > > > > approach to Quota.
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > These are our set of initial features which we
> > > > > > > propose to take out of ‘fully’ supported features. While
> > > > > > > we are in the process of making the user/developer
> > > > > > > experience of the project much better with providing well
> > > > > > > maintained codebase, we may come up with few more set of
> > > > > > > features which we may possibly consider to move out of
> > > > > > > support, and hence keep watching this space.
> > > > > > > [1] - http://review.gluster.org/4809
> > > > > > > [2] -
> > > > > > > https://github.com/gluster/glusterfs/issues/184
> > > > > > >
> > > > > > > Regards,
> > > > > > >
> > > > > > > Vijay, Shyam, Amar
> > > > > > >
> > > > > > >
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> > > > > > >
> > > > > > > _______________________________________________Glus
> > > > > > > ter-users mailing listGluster-users at gluster.org
> > > > > > > https://lists.glus
> > > > > > > --
> > > > > > > Sent from my Android device with K-9 Mail. All tyopes are
> > > > > > > thumb related and reflect
> > > > > > > authenticity.ter.org/mailman/listinfo/gluster-users
> > > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> > > --
> > > James P. Kinney III
> > > Every time you stop a school, you will have to build a jail. What
> > > yougain at one end you lose at the other. It's like feeding a dog
> > > on hisown tail. It won't fatten the dog.- Speech 11/23/1900 Mark
> > > Twain
> > > http://heretothereideas.blogspot.com/
> > --
> > James P. Kinney III
> > Every time you stop a school, you will have to build a jail. What
> > yougain at one end you lose at the other. It's like feeding a dog
> > on hisown tail. It won't fatten the dog.- Speech 11/23/1900 Mark
> > Twain
> > http://heretothereideas.blogspot.com/
> >
> >
> > _______________________________________________
> >
> > Gluster-users mailing list
> >
> > Gluster-users at gluster.org
> >
> > https://lists.gluster.org/mailman/listinfo/gluster-users
>
>
--
James P. Kinney III
Every time you stop a school, you will have to build a jail. What you
gain at one end you lose at the other. It's like feeding a dog on his
own tail. It won't fatten the dog.
- Speech 11/23/1900 Mark Twain
http://heretothereideas.blogspot.com/
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