Slashdot Mirror
Are There Large RDBMS Using Linux?
Jason Perlow of Linux Magazine writes:"
With all of the recent computer press coverage of Amazon and Intel converting their
web servers and other front end application servers to Linux, many of these stories
neglect to mention that the back end systems these companies use still rely on
commercial Unixes like Solaris, AIX and HPUX to host their RDBMSes (Oracle, DB2,
Sybase, Informix) for their mission critical transactional applications and data
mining.
Are there any companies out there actively using Linux to host a mission-critical
RDBMS ? or looking to replace UNIX with Linux for this purpose?"
Ok, maybe they are not huge, but Prada (Italian fashion designer and sponsor of "Luna Rossa" at the last America's Cup), uses Oracle running on RedHat stored on a pair of EMC Clariions for their datawarehouse.
I don't know what size the database is, but the Clariions had 400GB each worth of disks.
--
The world is divided in two categories:
those with a loaded gun and those who dig. You dig.
As distributions like SuSE continue pushing ahead with high-end features (like logical volume managers, which SuSE already has), usage of these products on Linux will undoubtedly increase. Part of the situation here is cost. When Oracle Enterprise Edition costs $40,000 per CPU, plus another $8,000 or so per year for support, who cares about spending a little more for high end Sun or IBM systems?
Also, Oracle 8i, while supported on Linux, did not offer a couple of features found in Oracle 8i for other systems. In particular, full interMedia support for full-text searches of all sorts of documents (especially from software made in Redmond) was not available in the 8i Linux version. The new 9i does support this feature under Linux.
Our company, a custom e-solutions provider, uses Oracle 9i on Linux almost exclusively because of Oracle's reliability and the fact that we have the resources in-house to support it. There is a caveat to this, though.
At $5,250 for just a 2-year. single processor standard edition license, 9i is not cheap and
most companies who already have an infrastructure built on it will not always realize a signifigant cost savings by moving to a Linux platform. 9i
Enterprise Edition is a cool $45K per processor so it is easy to see how the difference between $20K and $100K for an 8-way Intel versus an 8-way Sun
machine may not always be the determining factor in a platform decision for a system with a 5+ year time horizon.
In addition to the links above, most of the big database systems have active Linux ports. Any Oracle, Sybase, Informix or DB2, InterSystems, Poet, or Versant customer is a potential Linux customer.
If you are running a VLDB on Oracle, you want a 64-bit system; otherwise the SGA is limited to 2GIG.
Oracle only supports Linux x86, with all of its 32-bit memory constraints. Does Linux implement memory windows like 32-bit HP-UX?
Also, at linux.sybase.com, you can download for free the Alpha-axp version of Sybase ASE 11.0.3.3 - this is probably the most available commercial 64-bit database for Linux.
Really, the Linux and WinNT versions of Oracle are at the low end of the food chain.
We have four linux machines using Oracle 9i RAC for our database. The boxes are penguin computing 200x Relions each with qlogic 2200 fibre channel cards and an Intel 10/100 dual nic card, which ties into our SAN'd up Clariion 4500 disk processor/array. The three nics (including the onboard) gives us a frontend/app network, backup network, and an oracle IPC interface.
We have had success using Redhat 7.1 (upgraded kernel to use LVM) and Suse 7.2 (comes w/LVM) for the linux distribution. Do not attempt RAC or OPS without an LVM of some sort. It can be done, but it shouldn't.
The biggest expense you will have is the disk array, and you should not skimp on this. Buy fast reliable maintained disk.
The Linux solution beats out Sun solutions in price hands down. You are talking $30,000 per box for the minimal Sun allowed hardware requirement for the Sun Cluster software with the Oracle Parallel DB runtime licenses (this has changed with v3 and so have the hw requirements). The Sun Cluster software requires an extensive review process by Sun which basically insures your company has two extra of everything and can be onsite to help Sun with their software and hardware in 4 hours. If your company doesn't have it's shit together, Sun and the few vendors that even know what Sun Cluster is aren't even going to bother talking to you about it.
This Linux solutions beats out a Windows NT solution in reliablity over the simple fact that the disk and volume management is clumsy. There is no easy way to create labeled raw devices on a Windows machine. The process as I remembered it was creating unlabeled logic partitions for each disk space and then maintaining a file pointing to the value of the related registry key to map out the tablespaces. As soon as you added a partition, modified a partition, or even used another node to look at the partition table, you and the database were screwed (i.e. restore). This problem with managing shared disk may have been fixed in 2000.
The weakest point in the entire Oracle 9i RAC is the cluster software layer. Whether you are using Sun's Cluster Software, the Oracle supplied cluster manager for Linux, or the hardware vendor supplied OSD layer for Windows. Be prepared to spend serious time in monitoring and getting it under control with appropriate patches.
Once you have fought your way through all of this you can reap in the rewards that multiple nodes with shared data gives you. The greatest benefit is the ability to partition your data and your application which allows you more opportunities to scale. If your data does not partition by some logical means (date, timezone, city, planet, etc) forget about it. Just get a big honking database machine (especially you SAP/Peoplesoft poor SOBs).
No.
At the company I work for (which will remain unnamed because I am not in a position to speak on its behalf - but it is an old and large american company with a single character stock symbol) we use Oracle 8i on Compaq Proliants running Red Hat Linux - not only that but it's RH6.2 with all of the limitations of that line of kernels.
None of the databases are gigantic - 80Gb is the largest, but we haven't had any problems at all. If anything, most of these databases used to be on True64 (Digital Unix before that) and we had a lot of problems (although they were probably hardware related). Also - users have reported that performance is better (not that it was a real issue before) but we've never bothered/attempted to document that.
I can't say that the main factor for the move was money (although it was a factor) - after all, if you can afford the Oracle licenses you probably should not be cheap with the hardware/OS but we've had a whole lot of RH Linux for other applications and it just made sense to consolidate.
I run avidgamers.com, a community hosting service currently hosting around 7000 communities. We have 1.2 million records getting an average of 20 queries per second, ranging from sigle-record results to large summarizing queries. (With a fairly large part leaning towards the latter, tallying the number of replies to each thread in message boards.)
Running MySQL 3.23.40 on a 1.4GHz Athlon with 1GB of RAM and an 18GB 15krpm SCSI drive, the system is doing ok, but it's starting to feel the load peaks. I'll be upgrading to RAID fairly soon, which should help things.
All in all, I'm very happy with MySQL, but I'm strongly considering a move to Postgres, because the lack of row-level locking is starting to become a problem. Stability has been no problem... no crashes, no data corruption, nothing.
I'm sure this is in no way one of the largest installations of free software databases, but I thought I'd post my experiences anyway.
-- If no truths are spoken then no lies can hide --
"support. (who gives 24/7 support on postgress, and send out tech support guys giving consultations, will come on site on a sunday at 4am?)"
RedHat either already does or will soon.
"what OpenSource rdbms provide true mutli language support (we have records in cryllic, japanese, american, german, etc)?"
PostgreSQL.
"high availablity (i dont know the current state of HA functionality in the linux kernel)"
Why not look it up?
Become a FSF associate member before the low #s are used