Next Generation Cassandra

Tom WilkieFounder & VP Engineering, Acunu

Cassandra needs a team

• Installing, configuring and deploying

• Automating management operations

• Monitoring and alerting

• Testing and fixing bugs

• Tuning the garbage collector

• Tweaking the storage engine

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Acunu: your enterprise Cassandra Appliance

Commodity Hardware

Apache Cassandra

Acunu Storage Engine

Control Center

Data driven applications Web UI

Configured and tuned OS

4

Storage Engineaka Castle

Castle: Built for Big Data

• Storage engine optimized for large slow disks, many cores, Big Data workloads

• Enterprise density on commodity hardware

• Lightning disk rebuilds:10x faster than RAID

Acunu Kernel

Userspace

Doubling Arrays

arrays range

querieskey

insert

insertqueues

Bloom filters

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user

spac

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g a

rray

map

ping

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"Extent" layerextent

allocatorfreespacemanager

btreerange

queries

key get

key insert

Version tree

Streaming interfacekey

insertkey get

bufferedvalue get

bufferedvalue insert

range queries

Cache

flusher

extent blockcache

prefetcher

In-kernel workloads

shared buffersasync, sharedmemory ring

Shared memory interfacekeys

values

Arrays

value arrays

btree

key get

arraysmanagement

merges

• Opensource (GPLv2, MIT for user libraries)

• http://bitbucket.org/acunu

• Loadable Kernel Module, targeting CentOS’s 2.6.18

• http://www.acunu.com/blogs/andy-twigg/why-

Castle

http://goo.gl/gzihe

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0

1

2

3

4

5

RAID10, 8 Disks RAID5, 8 Disks RDA, 8 Disks RDA, 15 Disks

Re

bu

ild

Tim

e (

Ho

urs

)

Rebuild time

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Control Center

9

Control Center

The new UI has been critical in helping us work out what is wrong in our code

“The new UI has been critical in helping us work out what is wrong in our code”

- Matt Miller, TellyBug

Breaking System

13,000 tests per day

1.1 million tests per release

3.5k machine days of testing

for each release

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13

Short, unit tests

Data integrity tests

Distributed tests

Failure simulation

Tests for common, long running operations (bootstrap, decommission, backup, restore etc)

Resource usage tests (checking memory and cpu consumption)

Long running performance tests

“Turnkey Cassandra”

No need to master the internalsNo tuning required

No need for a committer on staff