Re: Migrating data from 2 node cluster to a 3 node cluster
Hello everybody, The thread below makes me wonder Does RF matter when using sstable loader.? My assumption was that stable loader will take care of RF when the streaming is done but just wanted to cross check. We are currently moving data from a RF=1 to RF=3 cluster by using sstable loader tool. We will of course be running repair on the destination nodes but was wondering how is the following issue resolved using a repair if my understanding is wrong? If the above assumption is wrong and since we are using Sstableloader which streams relevant parts to of each table to the destination cluster, it means the destination folder will only get one copy only (because origin RF =1 ) ? If that is the case, how will a repair resolve when a data chunk from an empty folder is used as the chosen replica to perform repair ( as it possible that two nearest neighbors are empty in the first place ) . Regards, Ananth From: aaron morton aa...@thelastpickle.commailto:aa...@thelastpickle.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Tuesday, July 9, 2013 3:24 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Migrating data from 2 node cluster to a 3 node cluster Without vnodes the initial_token is stored in the yaml file, as well as the system LocationInfo CF. With vnodes the only place the tokens are stored is in the system KS. So moving a node without it's system KS will cause it to generate new ones which will mean data is moved around. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/07/2013, at 11:23 AM, sankalp kohli kohlisank...@gmail.commailto:kohlisank...@gmail.com wrote: Leaving the system keyspaces behind is OK if you are not using vnodes. Why is it different for vnodes? On Mon, Jul 8, 2013 at 3:37 PM, aaron morton aa...@thelastpickle.commailto:aa...@thelastpickle.com wrote: This might work for user created keyspaces but might not work for system keyspace Leaving the system keyspaces behind is OK if you are not using vnodes. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.comhttp://www.thelastpickle.com/ On 9/07/2013, at 10:03 AM, sankalp kohli kohlisank...@gmail.commailto:kohlisank...@gmail.com wrote: If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. This might work for user created keyspaces but might not work for system keyspace On Mon, Jul 8, 2013 at 2:07 PM, Robert Coli rc...@eventbrite.commailto:rc...@eventbrite.com wrote: On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.commailto:comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
On Tue, Jul 9, 2013 at 12:36 AM, Ananth Gundabattula agundabatt...@threatmetrix.com wrote: The thread below makes me wonder Does RF matter when using sstable loader.? My assumption was that stable loader will take care of RF when the streaming is done but just wanted to cross check. We are currently moving data from a RF=1 to RF=3 cluster by using sstable loader tool. We will of course be running repair on the destination nodes but was wondering how is the following issue resolved using a repair if my understanding is wrong? sstableloader does in fact stream to all endpoints. That's why it's valuable that it has an --ignores option : if you successfully streamed to 2/3 replicas and 1/3 failed, you can --ignores the 2 which completed. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. This might work for user created keyspaces but might not work for system keyspace On Mon, Jul 8, 2013 at 2:07 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
This might work for user created keyspaces but might not work for system keyspace Leaving the system keyspaces behind is OK if you are not using vnodes. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/07/2013, at 10:03 AM, sankalp kohli kohlisank...@gmail.com wrote: If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. This might work for user created keyspaces but might not work for system keyspace On Mon, Jul 8, 2013 at 2:07 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
Leaving the system keyspaces behind is OK if you are not using vnodes. Why is it different for vnodes? On Mon, Jul 8, 2013 at 3:37 PM, aaron morton aa...@thelastpickle.comwrote: This might work for user created keyspaces but might not work for system keyspace Leaving the system keyspaces behind is OK if you are not using vnodes. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/07/2013, at 10:03 AM, sankalp kohli kohlisank...@gmail.com wrote: If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. This might work for user created keyspaces but might not work for system keyspace On Mon, Jul 8, 2013 at 2:07 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
Without vnodes the initial_token is stored in the yaml file, as well as the system LocationInfo CF. With vnodes the only place the tokens are stored is in the system KS. So moving a node without it's system KS will cause it to generate new ones which will mean data is moved around. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/07/2013, at 11:23 AM, sankalp kohli kohlisank...@gmail.com wrote: Leaving the system keyspaces behind is OK if you are not using vnodes. Why is it different for vnodes? On Mon, Jul 8, 2013 at 3:37 PM, aaron morton aa...@thelastpickle.com wrote: This might work for user created keyspaces but might not work for system keyspace Leaving the system keyspaces behind is OK if you are not using vnodes. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/07/2013, at 10:03 AM, sankalp kohli kohlisank...@gmail.com wrote: If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. This might work for user created keyspaces but might not work for system keyspace On Mon, Jul 8, 2013 at 2:07 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Jul 5, 2013 at 7:54 PM, srmore comom...@gmail.com wrote: RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. You have a cluster where RF=3 and N=2? Does it.. work? What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) If RF=N or RFN, you can just copy all SStables to all nodes, watching out for name collision. =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
On Thu, Jul 4, 2013 at 10:03 AM, srmore comom...@gmail.com wrote: We are planning to move data from a 2 node cluster to a 3 node cluster. We are planning to copy the data from the two nodes (snapshot) to the new 2 nodes and hoping that Cassandra will sync it to the third node. Will this work ? are there any other commands to run after we are done migrating, like nodetool repair. What RF are old and new cluster? What are the tokens of old and new nodes? http://www.palominodb.com/blog/2012/09/25/bulk-loading-options-cassandra =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
On Fri, Jul 5, 2013 at 6:08 PM, Robert Coli rc...@eventbrite.com wrote: On Thu, Jul 4, 2013 at 10:03 AM, srmore comom...@gmail.com wrote: We are planning to move data from a 2 node cluster to a 3 node cluster. We are planning to copy the data from the two nodes (snapshot) to the new 2 nodes and hoping that Cassandra will sync it to the third node. Will this work ? are there any other commands to run after we are done migrating, like nodetool repair. What RF are old and new cluster? RF of old and new cluster is the same RF=3. Keyspaces and schema info is also same. What are the tokens of old and new nodes? tokens for old cluster ( 2-node ) node 0 - 0 node 1 - 85070591730234615865843651857942052864 Tokens for new cluster (3-node) node 0 - 0 node 1 - 56713727820156407428984779325531226112 node 2 - 113427455640312814857969558651062452224 http://www.palominodb.com/blog/2012/09/25/bulk-loading-options-cassandra Thanks this helps a lot ! =Rob
Re: Migrating data from 2 node cluster to a 3 node cluster
You should run a nodetool repair after you copy the data over. You could also use the sstable loader, which would stream the data to the proper node. On Thu, Jul 4, 2013 at 10:03 AM, srmore comom...@gmail.com wrote: We are planning to move data from a 2 node cluster to a 3 node cluster. We are planning to copy the data from the two nodes (snapshot) to the new 2 nodes and hoping that Cassandra will sync it to the third node. Will this work ? are there any other commands to run after we are done migrating, like nodetool repair. Thanks all. -- Jon Haddad http://www.rustyrazorblade.com skype: rustyrazorblade
