Hi Tony, I don't know of any such plans at this time. At least some of us are trying to steer clear of full support for distributed query as it is a very hard problem that gets you deeply enmeshed in the details of particular databases and their SQL dialects, not to mention distributed query optimization. I therefore do not foresee this as a feature of Sequoia any time soon.
Cheers, Robert On 2/26/08 10:46 AM, "Anthony J. Biacco" <[EMAIL PROTECTED]> wrote: > > Also, is there any plans to inplement distributed joins for raid b-2? > Perhaps through a query parser in the controller, which detects a > join-type statement, then contacts a global catalog db/table on the db > servers that contains a list of the nodes that contain the table > requested? > > -Tony > --------------------------- > Manager, IT Operations > Format Dynamics, Inc. > 303-573-1800x27 > [EMAIL PROTECTED] > http://www.formatdynamics.com > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Anthony > J. Biacco > Sent: Tuesday, February 26, 2008 9:54 AM > To: Sequoia general mailing list > Subject: RE: [Sequoia] still being developed? (questions) > > > Thanx you for your answers Emmanuel. > My hesitation to use b-0 is the same as you pointed out, the distributed > joins. And being that it is the same for b-2 also, i'm not sure just > using b-1 (without a SAN) would work for us, as we plan to scale to a > larger database. probably 2TB+. Even being that disk space is cheap > these days, i'm not sure if doing 2TB in each node with a small number > of disk spindles is the right way to go. Especially, as i increase the > number of nodes and transactions. > I may end of going with the paralleldb option, san, and see how MySQL > w/GFS performs with a single storage instance. > > -Tony > --------------------------- > Manager, IT Operations > Format Dynamics, Inc. > 303-573-1800x27 > [EMAIL PROTECTED] > http://www.formatdynamics.com > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Emmanuel Cecchet > Sent: Tuesday, February 26, 2008 4:22 AM > To: Sequoia general mailing list > Subject: Re: [Sequoia] still being developed? (questions) > > Hi Anthony, >> 1. I understand that using sequoia kind of assumes a shared-nothing > disk >> architecture. But is it possible to use it with a SAN instead of > RAIDed? >> > If you use a SAN it means that your database supports shared-disk > clustering (like Oracle RAC) and already deals with the proper locking > and replication mechanism. >> Can you even specify no RAID level? > If your database readily supports replication (e.g. using a SAN), then > you can use the ParallelDB load balancer that just forwards requests to > your database cluster. In this case, Sequoia brings you load balancing, > transparent failover and eventuelly request caching. >> If so, does sequoia then have >> nothing to do with this and all the reading/writing would just fall > back >> to MySQL's standards and locking along with whatever filesystem i'd be >> using (probably GFS)? Would this even be possible or plausible? >> > Just to make sure that this is clear, Sequoia just relies on the > capabilities of the underlying databases. So if you try to use a SAN > with a database that has no support for it, Sequoia will not help in any > > way. >> 2. In trying to understand the RAIDed architecture in regards to >> sequoia, i'm not sure i understand something about the b-2 level. Does >> sequoia determine which tables go on which servers? Or would I > determine >> that schema? What happens when an extra database server is introduced >> into the mix? Does the schema re-partition the data automatically? > Does >> this need to be done manually? >> > In RAIDb-2, Sequoia will fetch the schema that is available on each > replica and proceed from there. If you want to force only specific > tables on each node, this can be specified manually in the virtual > database configuration file. The same thing applies when a new table > needs to be created, you can specify policies to create that table on a > specific set of nodes or choose dynamically nodes among a pool to select > > the less loaded ones. >> 3. For nested raid (b-0-1/b-1-0), is this a common config, and if so, >> can someone comment on how well this works in the real world, in > regards >> to performance and ease of recovery? >> > No this is not a common config and RAIDb-0 is rarely used because it > does not support distributed joins. If table A is on node 1 and table B > on node 2 and you try something like SELECT * FROM A,B you will get an > error that no node has both tables and the query cannot be executed. >> 4. In regards to the controller, where is this recommended to be > placed? >> on the app servers (tomcat), or the database servers? >> > There is no single answer to that. It depends how many app servers or > DBs you have. Sometimes you can collocate everything Tomcat/Sequoia/DB > and sometimes you use even dedicated machines for Sequoia controllers. > So all combinations are possible. > > Thanks for your interest in Sequoia, > Emmanuel -- Robert Hodges, CTO, Continuent, Inc. Email: [EMAIL PROTECTED] Mobile: +1-510-501-3728 Skype: hodgesrm _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia
