Axel Rau wrote:
Hi performers,
after following this list for a while, I try to configure a database
server with a limited budget.
Planned are 2 databases
- archiveopteryx - http://www.archiveopteryx.org/sql-schema.html
- ERDB -
https://www.chaos1.de/svn-public/repos/network-tools/ERDB/trunk/database/ERD.pdf
In peak times I expect something like
- 50 inserts
- 20 updates
- 200 selects
per second.
Presumably with multiple clients, not just one extremely busy one?
How big do you expect the databases to get? That'll affect the next point.
Current configuration is:
- Tyan S3992G3NR
- 2 x Opteron 2212 (2GHz)
- 8 GB RAM (DDR2-667)
Depending on the amount of data you've got to deal with, it might be
worth trading disks/cpu for more RAM.
- ARC-1261ML with 1GB and BBU
OK, so you can turn write-caching on. That should let you handle more
updates than you need. You probably don't need so much RAM on board
either, unless each update has a lot of data in it.
- 16 Seagate ST3250820NS (250GB, 7200 rpm, 8GB, with perpendicular
recording)
1 raid 1 for OS (FreeBSD) and WAL
1 raid 0 with 7 raid 1 for tablespace
Can I expect similar performance as 5 drives at 10k rpm (same costs)?
The main question is whether you're going to need to hit the disks
often. If you can get to the stage where the working-set of your DBs are
all in RAM you could sacrifice some disks. If not, disk I/O dominates.
Should I revert to a single-CPU to prevent from oscillating cache
updates between CPUS?
Anybody experience about NUMA stuff with FreeBSD?
Sorry - I know nothing about FreeBSD.
That any use - I didn't bother to reply before because I couldn't help
with the BSD stuff, and it's always guesswork with these sorts of questions.
--
Richard Huxton
Archonet Ltd
