Re: [PERFORM] Postgres and Ingres R3 / SAN
Folks, Ingres is based off of the same original codebase that PostgreSQL was based upon (a long time ago) This is wrong. According to Andrew Yu and others who date back to the original POSTGRES, development of Postgres involved several of the same team members as INGRES (most notably Stonebraker himself) but the two database systems share no code. So the two systems share some ideas and algorithms, but Postgres is a ground-up rewrite without borrowed code. -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [PERFORM] Postgres and Ingres R3 / SAN
Adding -performance back; you should do a reply-all if you want to reply to list messages. From: Jeremy Haile [mailto:[EMAIL PROTECTED] Can you point us at more info about this? I can't even find a website for Ingres... Ingres is based off of the same original codebase that PostgreSQL was based upon (a long time ago) It is owned by Computer Associates and was open sourced last year. It supports clustering and replication, and I've seen an Ingres install set up as a cluster backed by a SAN before. I just haven't talked to anyone (at least unbiased) who has used this type of setup in production, and I'm not fully aware of the advantages/disadvantages of this type of setup with Ingres. Since this group seems pretty knowledgable about performance advantages (and we are currently running PostgreSQL), I wanted to see if there were any experiences or opinions. Here is a link to their website: http://opensource.ca.com/projects/ingres Perhaps if you posted your performance requirements someone could help point you to a solution that would meet them. This is honestly more of a curiousity question at the moment, so I don't have any specific numbers. We definitely have a requirement for failover in the case of a machine failure, so we at least need Master-Slave replication. However, I wanted to solicit information on clustering alternatives as well, since scalability will likely be a future problem for our database. Ahh, ok... that's likely a much different requirement than true clustering. What a lot of folks do right now is segregate their application into a read-only stream and the more interactive read-write streams, and then use Slony to replicate data to a number of machines for the read-only work. This way anyone who's hitting the site read-only (and can handle some possible delay) will just hit one of the slave machines. People who are doing interactive work (updating data) will hit the master. Since most applications do far more reading than they do writing, this is a pretty good way to load-balance. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.comwork: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---(end of broadcast)--- TIP 6: explain analyze is your friend
Re: [PERFORM] Postgres and Ingres R3 / SAN
Please don't steal threds; post a new email rather than replying to an existing thread. On Mon, Mar 06, 2006 at 02:58:32PM -0500, Jeremy Haile wrote: Clustering solutions for PostgreSQL are currently pretty limited. Slony could be a good option in the future, but it currently only supports Master-Slave replication (not true clustering) and in my experience is a pain to set up and administer. Bizgres MPP has a lot of promise, especially for data warehouses, but it currently doesn't have the best OLTP database performance. So, I had a couple of questions: 1) I have heard bad things from people on this list regarding SANs - but is there a better alternative for a high performance database cluster? (both for redundancy and performance) I've heard internal storage touted before, but then you have to do something like master-master replication to get horizontal scalability and write performance will suffer. PostgreSQL on a SAN won't buy you what I think you think it will. It's essentially impossible to safely run two PostgreSQL installs off the same data files without destroying your data. What a SAN can buy you is disk-level replication, but I've no experience with that. 2) Has anyone on this list had experience using Ingres R3 in a clustered environment? I am considering using Ingres R3's built-in clustering support with a SAN, but am interested to know other people's experiences before we start toying with this possibility. Any experience with the Ingres support from Computer Associates? Good/bad? Can you point us at more info about this? I can't even find a website for Ingress... I'd be careful about OSS-based clusters. Everyone I've seen has some limitations, some of which are pretty serious. There are some that are command-based clustering/replication, but that raises some serious potential issues with non-deterministic functions among other things. Continuent seems to have done a good job dealing with this, but there's still some gotchas you need to be aware of. Then there's things like MySQL cluster, which requires that the entire database fits in memory. Well, if the database is in memory, it's going to be pretty dang fast to begin with, so you're unlikely to need scaleability across machines. Basically, truely enterprise-class clustering (and replication) are extremely hard to do, which is why this is pretty much exclusively the realm of the 'big 3' at this point. Slony-II could seriously change things when it comes out, though it still won't give you the data guarantees that a true syncronous multi-master setup does. But it will hopefully offer multi-master syncronous type behavior with the performance of an async database, which would be a huge leap forward. Perhaps if you posted your performance requirements someone could help point you to a solution that would meet them. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.comwork: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [PERFORM] Postgres and Ingres R3 / SAN
On Tue, 2006-03-07 at 13:00 -0600, Jim C. Nasby wrote: ... PostgreSQL on a SAN won't buy you what I think you think it will. It's essentially impossible to safely run two PostgreSQL installs off the same data files without destroying your data. What a SAN can buy you is disk-level replication, but I've no experience with that. It is possible to run two instances against the same SAN using tools such as RedHat's Cluster Suite. We use that in-house as a cheap alternative for Oracle clustering, although we're not using it for our PostgreSQL servers yet. It's not for load balancing, just active/passive fault tolerance. -- Mark Lewis ---(end of broadcast)--- TIP 6: explain analyze is your friend
Re: [PERFORM] Postgres and Ingres R3 / SAN
On Tue, Mar 07, 2006 at 11:20:50AM -0800, Mark Lewis wrote: On Tue, 2006-03-07 at 13:00 -0600, Jim C. Nasby wrote: ... PostgreSQL on a SAN won't buy you what I think you think it will. It's essentially impossible to safely run two PostgreSQL installs off the same data files without destroying your data. What a SAN can buy you is disk-level replication, but I've no experience with that. It is possible to run two instances against the same SAN using tools such as RedHat's Cluster Suite. We use that in-house as a cheap alternative for Oracle clustering, although we're not using it for our PostgreSQL servers yet. It's not for load balancing, just active/passive fault tolerance. True, but the OP was talking about scaleability, which is not something you get with this setup. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.comwork: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
[PERFORM] Postgres and Ingres R3 / SAN
Clustering solutions for PostgreSQL are currently pretty limited. Slony could be a good option in the future, but it currently only supports Master-Slave replication (not true clustering) and in my experience is a pain to set up and administer. Bizgres MPP has a lot of promise, especially for data warehouses, but it currently doesn't have the best OLTP database performance. So, I had a couple of questions: 1) I have heard bad things from people on this list regarding SANs - but is there a better alternative for a high performance database cluster? (both for redundancy and performance) I've heard internal storage touted before, but then you have to do something like master-master replication to get horizontal scalability and write performance will suffer. 2) Has anyone on this list had experience using Ingres R3 in a clustered environment? I am considering using Ingres R3's built-in clustering support with a SAN, but am interested to know other people's experiences before we start toying with this possibility. Any experience with the Ingres support from Computer Associates? Good/bad? Jeremy ---(end of broadcast)--- TIP 6: explain analyze is your friend
