Re: adding node to cluster
On Thu, Aug 30, 2012 at 10:39 PM, Casey Deccio ca...@deccio.net wrote: In what way are the lookups failing? Is there an exception? No exception--just failing in that the data should be there, but isn't. At ConsistencyLevel.ONE or QUORUM? If you are bootstrapping the node, I would expect there to be no chance of serving blank reads like this. As auto_bootstrap is set to true by default, I presume you are bootstrapping. Which node are you querying to get the no data response? =Rob -- =Robert Coli AIMGTALK - rc...@palominodb.com YAHOO - rcoli.palominob SKYPE - rcoli_palominodb
adding node to cluster
All, I'm adding a new node to an existing cluster that uses ByteOrderedPartitioner. The documentation says that if I don't configure a token, then one will be automatically generated to take load from an existing node. What I'm finding is that when I add a new node, (super) column lookups begin failing (not sure if it was the row lookup failing or the supercolumn lookup failing), and I'm not sure why. I assumed that while the existing node is transitioning data to the new node the affected rows and (super) columns would still be found in the right place. Any idea why these lookups might be failing? When I decommissioned the the new node, the lookups began working again. Any help is appreciated. Regards, Casey
Re: adding node to cluster
On Thu, Aug 30, 2012 at 10:18 AM, Casey Deccio ca...@deccio.net wrote: I'm adding a new node to an existing cluster that uses ByteOrderedPartitioner. The documentation says that if I don't configure a token, then one will be automatically generated to take load from an existing node. What I'm finding is that when I add a new node, (super) column lookups begin failing (not sure if it was the row lookup failing or the supercolumn lookup failing), and I'm not sure why. 1) You almost never actually want BOP. 2) You never want Cassandra to pick a token for you. IMO and the opinion of many others, the fact that it does this is a bug. Specify a token with initial_token. 3) You never want to use Supercolumns. The project does not support them but currently has no plan to deprecate them. Use composite row keys. 4) Unless your existing cluster consists of one node, you almost never want to add only a single new node to a cluster. In general you want to double it. In summary, you are Doing It just about as Wrong as possible... but on to your actual question ... ! :) In what way are the lookups failing? Is there an exception? =Rob -- =Robert Coli AIMGTALK - rc...@palominodb.com YAHOO - rcoli.palominob SKYPE - rcoli_palominodb
Re: adding node to cluster
On Thu, Aug 30, 2012 at 11:21 AM, Rob Coli rc...@palominodb.com wrote: On Thu, Aug 30, 2012 at 10:18 AM, Casey Deccio ca...@deccio.net wrote: I'm adding a new node to an existing cluster that uses ByteOrderedPartitioner. The documentation says that if I don't configure a token, then one will be automatically generated to take load from an existing node. What I'm finding is that when I add a new node, (super) column lookups begin failing (not sure if it was the row lookup failing or the supercolumn lookup failing), and I'm not sure why. 1) You almost never actually want BOP. 2) You never want Cassandra to pick a token for you. IMO and the opinion of many others, the fact that it does this is a bug. Specify a token with initial_token. 3) You never want to use Supercolumns. The project does not support them but currently has no plan to deprecate them. Use composite row keys. 4) Unless your existing cluster consists of one node, you almost never want to add only a single new node to a cluster. In general you want to double it. In summary, you are Doing It just about as Wrong as possible... but on to your actual question ... ! :) Well, at least I'm consistent :) Thanks for the hints. Unfortunately, when I first brought up my system--with the goal of getting it up quickly--I thought BOP and Supercolumns were the way to go. Plus, the small cluster of nodes I was using was on a hodgepodge of hardware. I've since had a chance to think somewhat about redesigning and rearchitecting, but it seems like there's no easy way to convert it properly. Step one was to migrate everything over to a single dedicated node on reasonable hardware, so I could begin the process, which brought me to the issue I initially posted about. But the problem is that this is a live system, so data loss is an issue I'd like to avoid. In what way are the lookups failing? Is there an exception? No exception--just failing in that the data should be there, but isn't. Casey
