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From Hannu Kröger <hkro...@gmail.com>
Subject Re: Upgrading 1.1 to 1.2 in-place
Date Mon, 30 Dec 2013 14:17:44 GMT
Hi,

Random Partitioner + VNodes are a supported combo based on DataStax
documentation:
http://www.datastax.com/documentation/cassandra/1.2/webhelp/cassandra/architecture/architecturePartitionerAbout_c.html

How else would you even migrate from 1.1 to Vnodes since migration from one
partitioner to another is such a huge amount of work?

Cheers,
Hannu


2013/12/30 Edward Capriolo <edlinuxguru@gmail.com>

> What is the technical limitation that vnodes need murmer? That seems
> uncool for long time users?
>
>
> On Monday, December 30, 2013, Jean-Armel Luce <jaluce06@gmail.com> wrote:
> > Hi,
> >
> > I don't know how your application works, but I explained during the last
> Cassandra Summit Europe how we did the migration from relational database
> to Cassandra without any interruption of service.
> >
> > You can have a look at the video C* Summit EU 2013: The Cassandra
> Experience at Orange
>
> >
> > And use the mod-dup module https://github.com/Orange-OpenSource/mod_dup
> >
> > For copying data from your Cassandra cluster 1.1 to the Cassandra
> cluster 1.2, you can backup your data and then use sstableloader (in this
> case, you will not have to modify the timestamp as I did for the migration
> from relational to Cassandra).
> >
> > Hope that helps !!
> >
> > Jean Armel
> >
> >
> >
> > 2013/12/30 Tupshin Harper <tupshin@tupshin.com>
> >>
> >> No.  This is not going to work.  The vnodes feature requires the
> murmur3 partitioner which was introduced with Cassandra 1.2.
> >>
> >> Since you are currently using 1.1, you must be using the random
> partitioner, which is not compatible with vnodes.
> >>
> >> Because the partitioner determines the physical layout of all of your
> data on disk and across the cluster, it is not possible to change
> partitioner without taking some downtime to rewrite all of your data.
> >>
> >> You should probably plan on an upgrade to 1.2 but without also
> switching to vnodes at this point.
> >>
> >> -Tupshin
> >>
> >> On Dec 30, 2013 9:46 AM, "Katriel Traum" <katriel@google.com> wrote:
> >>>
> >>> Hello list,
> >>> I have a 2 DC set up with DC1:3, DC2:3 replication factor. DC1 has 6
> nodes, DC2 has 3. This whole setup runs on AWS, running cassandra 1.1.
> >>> Here's my nodetool ring:
> >>> 1.1.1.1  eu-west     1a          Up     Normal  55.07 GB        50.00%
>              0
> >>> 2.2.2.1  us-east     1b          Up     Normal  107.82 GB
> 100.00%             1
> >>> 1.1.1.2  eu-west     1b          Up     Normal  53.98 GB        50.00%
>              28356863910078205288614550619314017622
> >>> 1.1.1.3  eu-west     1c          Up     Normal  54.85 GB        50.00%
>              56713727820156410577229101238628035242
> >>> 2.2.2.2  us-east     1d          Up     Normal  107.25 GB
> 100.00%             56713727820156410577229101238628035243
> >>> 1.1.1.4  eu-west     1a          Up     Normal  54.99 GB        50.00%
>              85070591730234615865843651857942052863
> >>> 1.1.1.5  eu-west     1b          Up     Normal  55.1 GB         50.00%
>              113427455640312821154458202477256070484
> >>> 2.2.2.3  us-east     1e          Up     Normal  106.78 GB
> 100.00%             113427455640312821154458202477256070485
> >>> 1.1.1.6  eu-west     1c          Up     Normal  55.01 GB        50.00%
>              141784319550391026443072753096570088105
> >>>
> >>> I am going to upgrade my machine type, upgrade to 1.2 and change the
> 6-node to 3 nodes. I will have to do it on the live system.
> >>> I'd appreciate any comments about my plan.
> >>> 1. Decommission a 1.1 node.
> >>> 2. Bootstrap a new one in-place, cassandra 1.2, vnodes enabled (I am
> trying to avoid a re-balance later on).
> >>> 3. When done, decommission nodes 4-6 at DC1
> >>> Issues i've spotted:
> >>> 1. I'm guessing I will have an unbalanced cluster for the time period
> where I have 1.2+vnodes and 1.1 mixed.
> >>> 2. Rollback is cumbersome, snapshots won't help here.
> >>> Any feedback appreciated
> >>> Katriel
> >
> >
>
> --
> Sorry this was sent from mobile. Will do less grammar and spell check than
> usual.
>

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