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Disposable Environments at Scale

or: How I Learned to Stop Worrying and Love ZFS

Eric Sproul

Build EngineerSysadmin

Consultant

Twitter:@eirescot

Recipe for Success

enablement (n): the act of providing (someone)with adequate power, means, opportunity or authority(to do something)

This is a story of how ZFS enabled business success

Background

Etsy is the world's handmade marketplace

Experiencing rapid growth

Every department needed to understandhow the business was evolving

Asked OmniTI for help

The Situation

No data warehouse

Analytical queries againstPostgreSQL OLTP

Large initial size (~250 GB)

Forecast to reach 1 TB+within a year

Problems

Long-running queries to OLTPdestroy web performance

Re-running reportsproduces different results

Inflexible reporting interface

Requirements

Relieve pressure fromOLTP database

Make production datacontinuously available

Enable correlationof other sources

Flexible reporting UI

Solution

Create separate BI analytics DB

Build it on ZFS

Initial Capabilities

ETL to collate table-level datafrom multiple databases

Run deep analytic querieswithout impacting website

New web UI enables ad-hoc reporting

Reaping the Benefits of ZFS

Snapshots

Faster backups

Simple replica creation

Reaping the Benefits of ZFS

CompressionExtend usable life of storage:

PgSQL logical: 1.3TOn-disk: 653G (2.0x)

Intelligent resilverShorter rebuilds ==

Reduced risk of data loss

We Want More!

Monthly reports now on BI system

Occasional problems requirere-running reports

Still get different results,same as before

We Want More!

Need to test report changes

Fine to dev with small mock-up

Staging requires somethingthat looks like production

The Next Level

Disposable environments

Run on slave replica

R/W copy of BI data

Discard when finished

Disposable Environment

Use a non-global zone

set zonepath=/zones/bistageset autoboot=trueset limitpriv=default,dtrace_proc,dtrace_userset ip-type=sharedadd netset address=10.1.2.3set physical=bnx0endadd datasetset name=bi01tank/stageend

Disposable Environment

Starting state: ZFS datasets

bi01tank/pgsql/databi01tank/pgsql/data/91bi01tank/pgsql/wal_archivebi01tank/pgsql/wal_archive/91

Disposable Environment

Take snapshots

bi01tank/pgsql/data@stagebi01tank/pgsql/data/91@stagebi01tank/pgsql/wal_archive@stagebi01tank/pgsql/wal_archive/91@stage

zfs snapshot -r bi01tank/pgsql/data@stage

Disposable Environment

Create clones

bi01tank/pgsql/data@stagebi01tank/pgsql/data/91@stagebi01tank/pgsql/wal_archive@stagebi01tank/pgsql/wal_archive/91@stage

bi01tank/stage/databi01tank/stage/data/91bi01tank/stage/wal_archivebi01tank/stage/wal_archive/91

zfs clone <src_dataset>@stage <dst_dataset>

Disposable Environment

Zone now sees a full, writable copy of data

Unchanged data is referenced to origin

Changes accumulate to clone

Disposable Environment

pgsql/data/91 pgsql/data/91@stage stage/data/91

Change accountedto clone

Unchanged datareferenced fromsnapshot

Live FS Snapshot Clone

Next-Level Results

Any report can be re-runon the same data

Massage existing data orbring more in for ad-hoc report

Test changes to reports and web UI

Next-Level Results

When finished with the environment:

Shut down zone

Delete clone & origin snap

Return on Investment

BI database runs on 2 machines

OLTP database lifetime extendedtwo years past expectation

Faster, more granular, and ad-hoc reportingenables better decisions by management

Bonus!

With the same technique,we can safely test:

PostgreSQL upgrades

Schema changes

Thank You

ZFS, Zones and much moreare available to the community via

illumos and its distributions

Go forth and enable your business!