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From Serega Sheypak <>
Subject Re: Multinode Cassandra and sstableloader
Date Tue, 31 Mar 2015 13:32:33 GMT
>I have to ask you if you considered doing an Alter keyspace, change RF
The idea is dead simple:
get data from cluster1,
put it to cluster2
vipe cluster1

I understand drawbacks of streaming sstableloader approach, I need right
now something easy. Later we consider switch to Priam since it does
backup/restore in a right way.

2015-03-31 14:45 GMT+02:00 Alain RODRIGUEZ <>:

> Hi,
> Despite of "I understand that it's not the best solution, I need it for
> testing purposes", I have to ask you if you considered doing an Alter
> keyspace, change RF > 1 for mykeyspace on cluster2 and "nodetool rebuild"
> to add a new DC (your cluster2) ?
> In the case you go your way (sstableloader) also advice you to make a
> snapshot (instead of just flushing) to avoid fails due to compactions on
> your active cluster1.
> To answer your question, sstableloader is supposed to distribute correctly
> data on the new cluster depending on your RF and topology.
> Basically if you run sstable loader just on sstable c1.node1 my guess is
> that you will have all the data present on c1.node1 stored on the new c2
> (each data to corresponding node). So if you have an RF=3 on c1, you should
> have all the data on c2 just by running sstableloader from c1.node1, if you
> are using RF=1 on c1, then you need to load data from c1.each_node. I
> suppose that cluster2.nodeXXX doesn't matter and act as a coordinator.
> I never used the tool, but that's what would be "logical" imho. Wait for a
> confirmation as I wouldn't to lead you to a failure of any kind. Also, I
> don't know if data is also replicated directly with sstableloader or if you
> need to repair c2 after loading data.
> C*heers,
> Alain
> 2015-03-31 13:21 GMT+02:00 Serega Sheypak <>:
>>  Hi, I have a simple question and can't find related info in docs.
>> I have cluster1 with 3 nodes and cluster2 with 5 nodes. I want to
>> transfer whole keyspace named 'mykeyspace' data from cluster1 to cluster2
>> using sstableloader. I understand that it's not the best solution, I need
>> it for testing purposes.
>> What I'm going to do:
>>    1. Recreate keyspace schema on cluster2 using schema from cluster1
>>    2. nodetool flush for mykeyspace.source_table being exported from
>>    cluster1 to cluster2
>>    3.
>>    Run sstableloader for each table on cluster1.node01
>>    sstableloader -d
>>    /var/lib/cassandra/data/mykeyspace/source_table-83f369e0d6e511e4b3a6010e8d2b68af/
>> What should I get as a result on cluster2?
>> *ALL* data from source_table?
>> or
>> Just data stored in *partition of source_table*
>> I'm confused. Doc says I just run this command to export table from
>> cluster1 to cluster2, but I specify path to a part of source_table data,
>> since other parts of table should be on other nodes.

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