PostgreSQL on FreeBSD

Transcription

1 2ndQuadrant US 05/12/2010

2 About this presentation The master source for these slides is Slides are released under the Creative Commons Attribution 3.0 United States License

3 What do I know? 2ndQuadrant supports PostgreSQL installs all over the world PostgreSQL contributor specializing in performance tuning Worked on rewrites of checkpoint and background writer code in PostgreSQL 8.3 (2007) Focus on high write volume environments Ran an ISP, wrote a Linux wireless driver

4 PostgreSQL dog food eaten from FreeBSD bowl postgresql.org run in FreeBSD jails hub.org: ISP run by a PostgreSQL core member Lots of personal developer systems running FreeBSD before everyone got Macs

5 Observed operating systems for PostgreSQL Rough estimates based on recent personal work I ve done Linux: 60%, stable Solaris: 15%, shrinking Windows: 10%, growing FreeBSD: 10%, stable OS X and other UNIXes: 5%, shrinking Serious business database systems are heavily UNIX biased Windows dramatically more popular in general PostgreSQL community Solaris systems used to include some SPARC, databases I ve seen recently have all moved to x86

6 Hardware Vendors for Linux Systems More rough estimates based on recent work Dell: 60% White box: 20% HP: 15% Sun: 5% IBM Linux systems don t really have the right controller/disk mix for database work

7 Drivers that database apps care about RAID controllers, specifically need battery-backed cache for fast fsync Sometimes even use software RAID or ZFS with RAID controllers in JBOD mode Basic network card support

8 Dell RAID compatibility PERC6 (mfi): rebranded LSI Logic, well supported, cards very fast PERC H700, H800: Newer LSI card. Not well tested, LSI driver shouldn t take much work PERC H200: Newer and different LSI card, not useful for databases

9 HP RAID compatibility P400, P600, P800 (ciss): Stable driver, speed scales based on card

10 White box vendors LSI MegaRAID (amr): Stable driver, very fast AMCC/3ware (twa): Stable driver and popular, medium speed Areca (arcmsr): Not well tested on latest cards, fast Management utilities often use Linux compatibility

11 High-end systems with Fiber Channel SANs popular for mission critical applications: EMC etc. For good performance, must use fiber channel Emulex is considered the leader for FC cards No FreeBSD driver for Emulex QLogic is main alternative Administrators are split over which card is better, those preferring Emulex can t consider FreeBSD Blocker for many FreeBSD deployments in large companies and smaller ones that plan to scale upward

12 Corporate FUD: choose Linux instead of FreeBSD Missing obvious and large commercial support vendor, Linux has RedHat, SuSE, Canonical Hardware vendors don t certify systems, hardware may not be supported Smaller user base UFS2 uses soft updates instead of journaling ZFS implementation isn t solid enough yet compared to Solaris

13 Plenty of PostgreSQL issues on Linux Filesystem implementations are terrible fsync implementation very course O SYNC writes known to quietly fail Most portable database implementation details almost deprecated No respect for processes and shared memory Out of memory killer targets database server No optimizing write cache for latency instead of throughput

14 Even more PostgreSQL issues on Solaris Oracle owns Sun

15 Features PostgreSQL Likes in FreeBSD ZFS block checksums and snapshots DTrace compatibility, database is already filled with probes Good control over filesystem read and write cache: UFS2 vfs.hirunningspace is easy to understand Stable APIs, POSIX compliance BSD License, community driven

16 A Great Future for FreeBSD and PostgreSQL? Preinstalled on hardware from vendors like Dell, HP Performance/stability lab on popular platforms Drivers for small to large systems Innovation on top of the features from Solaris Plenty of profitable support companies with little work to do Serious committers on both sides with full dog bowls

17 Questions? : greg@2ndquadrant.com PostgreSQL mailing lists