Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Tuning Linux for Databases
Search
Alexey Lesovsky
October 15, 2016
Education
0
49
Tuning Linux for Databases
Slides from my talk at HDConf 2016 Minsk, Belarus
Alexey Lesovsky
October 15, 2016
Tweet
Share
More Decks by Alexey Lesovsky
See All by Alexey Lesovsky
PostgreSQL Scaling Usecases
lesovsky
0
100
Patroni failure stories, or How to crash yout PostgreSQL cluster
lesovsky
0
420
PostgreSQL High Availability in 2019
lesovsky
0
360
Top developer's mistakes when working with PostgreSQL
lesovsky
1
140
Let's Pull the Plug On the Autovacuum (EN)
lesovsky
0
1.2k
Troubleshooting PostgreSQL for Developers (RU)
lesovsky
2
350
Troubleshooting PostgreSQL Streaming Replication
lesovsky
0
970
Call of Postgres: Advanced Operations. Part I.
lesovsky
0
64
Call of Postgres: Advanced Operations. Part II.
lesovsky
0
78
Other Decks in Education
See All in Education
サンキッズゾーン 春日井駅前 ご案内
sanyohomes
0
900
社外コミュニティの歩き方
masakiokuda
2
180
Transición del Management al Neuromanagement
jvpcubias
0
200
2025年度春学期 統計学 第9回 確からしさを記述する ー 確率 (2025. 6. 5)
akiraasano
PRO
0
150
DIP_1_Introduction
hachama
0
120
探査機自作ゼミ2025スライド
sksat
3
760
万博非公式マップとFOSS4G
barsaka2
0
1.1k
Sponsor the Conference | VizChitra 2025
vizchitra
0
620
核燃料政策を問う─英国の決断と日本
hide2kano
0
180
Dashboards - Lecture 11 - Information Visualisation (4019538FNR)
signer
PRO
1
2.1k
20250807_がんばらないコミュニティ運営
ponponmikankan
0
160
みんなのコード 2024年度活動報告書/ 2025年度活動計画書
codeforeveryone
0
280
Featured
See All Featured
Gamification - CAS2011
davidbonilla
81
5.4k
Java REST API Framework Comparison - PWX 2021
mraible
33
8.8k
I Don’t Have Time: Getting Over the Fear to Launch Your Podcast
jcasabona
33
2.4k
Become a Pro
speakerdeck
PRO
29
5.5k
Stop Working from a Prison Cell
hatefulcrawdad
271
21k
A designer walks into a library…
pauljervisheath
207
24k
Building a Scalable Design System with Sketch
lauravandoore
462
33k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
34
6k
Designing for Performance
lara
610
69k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
8
520
Docker and Python
trallard
45
3.6k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
31
2.2k
Transcript
None
About PostgreSQL DBA. Linux system administrator. PostgreSQL-Consulting.com: • 24/7 support.
• Audit, performance optimizations. • Consulting and Training. • Monitoring and Emergency. • Capacity planning. Slides: https://goo.gl/awmZ2H
Agenda RDBMS on Linux, why? Databases and Resources. OS subsystems.
CPU, Process scheduling, Power saving policies. Memory, VM, NUMA, Huge pages. Storage, File Systems, Input/Output. Other misc.
Why Linux? Linux is a good choice: • Active development
& Community support. • A lot of features & Fast implementation. • Stable & Mature & Durable.
Databases & Resources Concurrency Query speed Sort, group, hash,... OS
page cache DB buffer pool Local process cache DB data files Transaction Log Cold start CPU Memory Storage
Databases & Resources CPU Scheduling NUMA Power Saving Virtual Memory
NUMA Huge Pages File Systems Storage I/O CPU Memory Storage
Resources CPU scheduler. Virtual memory and NUMA. Huge pages. File
systems. Storage IO. Power saving policy. Others.
CPU scheduling CPU scheduler responsible for proper processes planning: Sysctl:
• kernel.sched_migration_cost_ns = 5000000 (default: 500000). • kernel.sched_autogroup_enabled = 0 (default: 1). http://www.postgresql.org/message-id/
[email protected]
http://kernelnewbies.org/Linux_2_6_38#head-59575a6aeafa38490226a560ee02de89829a5b20
CPU scheduling CPU scheduler responsible for proper processes planning: Sysctl:
• kernel.sched_migration_cost_ns = 5000000 (default: 500000). • kernel.sched_autogroup_enabled = 0 (default: 1). http://www.postgresql.org/message-id/
[email protected]
http://kernelnewbies.org/Linux_2_6_38#head-59575a6aeafa38490226a560ee02de89829a5b20 Be aware on Ubuntu: 12.04 #1055222 and 14.04 #1422016. Use noautogroup kernel param instead of sysctl.conf.
Virtual Memory What is it? Allocator, Caching, Dirty pages and
Writeback.
Virtual Memory
Virtual Memory Sysctl: vm.dirty_background_ratio & vm.dirty_ratio = disable it. vm.dirty_background_bytes
& vm.dirty_bytes = depends on ... RAID cache size, 64MB/128MB otherwise
Virtual Memory Out-of-memory & OOM-Killer Sysctl: vm.swappiness = 1 (default:
60)
NUMA S — Socket C — CPU core M —
Memory bank
NUMA BIOS: enable memory node interleaving. Kernel boot: numa=off. numactl
utility. Sysctl: • vm.zone_reclaim_mode = 0 (default: 0). • kernel.numa_balancing = 0 (default: 0).
Huge Pages Huge pages vs. Transparent huge pages. Huge pages
are supported by many RDBMS. Always disable transparent huge pages.
Huge Pages Huge pages vs. Transparent huge pages. Huge pages
are supported by many RDBMS. Always disable transparent huge pages. /etc/rc.local: • echo never > /sys/kernel/mm/transparent_hugepage/enabled • echo never > /sys/kernel/mm/transparent_hugepage/defrag
Filesystems Ext3 vs Ext4 vs XFS: what is better? Filesystem
Barriers.
Filesystems Ext3 vs Ext4 vs XFS: what is better? Filesystem
Barriers. Disable Write Cache: • hdparm -W0 /dev/device • MegaCli64 -LDSetProp -DisDskCache -Lall -aALL
Filesystems Ext3 vs Ext4 vs XFS: what is better? Filesystem
Barriers. Disable Write Cache: • hdparm -W0 /dev/device • MegaCli64 -LDSetProp -DisDskCache -Lall -aALL Hardware RAID + BBU = barrier=0 (disable). Software RAID = barrier=1 (enable).
Filesystems Ext3 vs Ext4 vs XFS: what is better? Filesystem
Barriers. Disable Write Cache: • hdparm -W0 /dev/device • MegaCli64 -LDSetProp -DisDskCache -Lall -aALL Hardware RAID + BBU = barrier=0 (disable). Software RAID = barrier=1 (enable). Enterprise SSD with Power Loss Protection = barrier=0 (disable).
Storage IO SATA/SAS vs SSD. IO elevators.
Storage IO SATA/SAS vs SSD. IO elevators: • noop: SSD,
PCIe SSD, hi-end storages. • deadline: RAID, SATA/SAS. • cfq: good default. • none (multi-queue block IO): SSD, PCIe SSD.
Storage IO SATA/SAS vs SSD. IO elevators: • noop: SSD,
PCIe SSD, hi-end storages. • deadline: RAID, SATA/SAS. • cfq: good default. • none (multi-queue block IO): SSD, PCIe SSD. # echo 'elevator_name' > /sys/block/<device>/queue/scheduler kernel boot: elevator=<name> /sys/block/*/queue/: rotational, rq_affinity, read_ahead_kb
Power Saving Policy Drivers: acpi_cpufreq vs. intel_pstate. scaling_governor.
Power Saving Policy Drivers: acpi_cpufreq vs. intel_pstate. scaling_governor: • /sys/devices/system/cpu/cpuX/cpufreq/scaling_available_governors
• /sys/devices/system/cpu/cpuX/cpufreq/scaling_governor
Power Saving Policy Drivers: acpi_cpufreq vs. intel_pstate. scaling_governor: • /sys/devices/system/cpu/cpuX/cpufreq/scaling_available_governors
• /sys/devices/system/cpu/cpuX/cpufreq/scaling_governor acpi_cpufreq + performance. intel_pstate + powersave.
Misc: Clocksources What is clocksource? acpi_pm vs. hpet vs. tsc.
/sys/devices/system/clocksource/clocksource0/available_clocksource. /sys/devices/system/clocksource/clocksource0/current_clocksource.
Summary Linux is a good choice for RDBMS: Modern, Universal,
Flexible, Stable. Adapt Linux for your workloads. Test → Change → Test → Commit/Rollback.
Questions? Alexey Lesovsky
[email protected]
PostgreSQL-Consulting.com: Data maintenance at its best
https://postgresql-consulting.com