ScyllaDB V Developer Deep Dive Series: Resiliency and Strong Consis...

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

ScyllaDB V Developer Deep Dive
Series: Resiliency and Strong
Consistency via Raft
Konstantin Osipov, Director, Software En...

UPCOMING WEBINAR
August 18
Rust-Based Drivers
and UDFs with
WebAssembly
Performance
Enhancements
+ AWS I4i
Benchmarking
ON...

Brought to you by
VIRTUAL EVENT | OCTOBER 19 + 20
All Things Performance
The event for developers who care about P99
perce...

Poll
Where are you in your NoSQL adoption?

ScyllaDB V Developer Deep Dive
Series: Resiliency and Strong
Consistency via Raft
Konstantin Osipov, Director, Software En...

+ Infoworld 2020 Technology of the Year!
+ Founded by designers of KVM Hypervisor
The Database Built for Gamechangers
6
“S...

7
+400 Gamechangers Leverage ScyllaDB
Seamless experiences
across content + devices
Fast computation of ﬂight
pricing
Corp...

Konstantin Osipov
8
Director of Engineering, ScyllaDB
+ Worked on Consensus Algorithms in
ScyllaDB
+ Crazy about distribut...

Agenda ■ Raft in ScyllaDB
■ Schema and Topology Consistency in ScyllaDB 5.x
■ QA
9

The Problem with Metadata
Eventual Consistency

What is Database Schema?

Replicating Schema Changes
7
7
6
6
5
CREATE KEYSPACE
clicks
WITH { replication … }

Consistency Model of Schema Changes
id ﬁrst last
1 John Doe
Time
Node A: Node B:
id ﬁrst last email
1 John Doe
2 Jenny Smi...

(In)consistency of Schema Changes
cqlsh:test> create table t (a int primary key);
----------------------------------------...

Eventual Consistency of
Topology Changes

What is Topology?
Topology is deﬁned as all of the following:
the set of nodes in the cluster,
location of those nodes in ...

Token Metadata
{A, C}
{C, B}
{B, A}
{C, A}
{A, B}
{B, C}
token ring replication
metadata
create
keyspace …
with {
replicat...

Eventually (In)consistent Topology
node A node B node C
A
B
A
B
Token
Metadata
A
C
B
C
A
B
A
C
B
C
A
B
C

Eventually (In)consistent Topology
“Cannot” happen:
“Before adding the new node,
check the node’s status in the cluster us...

Strongly Consistent Topology
The plan:
+ Make the database responsible for consistency under all conditions
Why:
+ Gives a...

What is Raft?

Raft Intro
Raft is a protocol for state machine replication.
What does it mean?
■ The majority of nodes have the same stat...

How Raft Achieves Consistency
State
machine
State
machine
State
machine
Node A Node B Node C

How Raft Achieves Consistency
State
machine
Log
x←1 y←2 z←3
State
machine
Log
x←1 y←2 z←3
State
machine
Log
x←1 y←2 z←3
No...

How Raft Achieves Consistency
Consensus
module
State
machine
Log
x←1 y←2 z←3
Consensus
module
State
machine
Log
x←1 y←2 z←...

Leader Based Replication
7
6
6
6
6
CREATE KEYSPACE
clicks
WITH { replication … }

Detecting a Leader Failure
🔥
B
C
D
E
��
��
��
��
● Leader regularly pings
followers
● Followers become candidates
when don...

Raft Leadership Changes
Election starts: S1 is a candidate: More candidates: S1 is elected leader:
T i m e

Raft Conﬁguration Changes
x←1
add
node D
y←2 z←3
del
node A
Time
Replicated log

Scylla Raft Extensions
■ Resilience against asymmetric network failures with pre-voting
■ Increased liveness for very larg...

The Balance Between
Consistency and Availability

+ RAFT eagerly replicates to every node
+ Like RF=ALL tables with auto-repair
+ Request coordinators still use the local v...

Split Brain Problem
App
App
App
App
App
App

Solved Issues
■ Concurrent DDL is now safe
■ Safe topology changes enable elasticity
■ still under --experimental-features...

Steps to Stronger Consistency in ScyllaDB
+ Tests, tests and more tests
+ Schema consistency - Experimental in 5.0
+ Topol...

Poll
How much data do you under management of your
transactional database?

Q&A
August 18
Rust-Based
Drivers and
UDFs with
WebAssembly
Resiliency
and Strong
Consistency
via Raft
ON-DEMAND WEBINAR UP...

Thank you
for joining us today.
@scylladb scylladb/
slack.scylladb.com
@scylladb company/scylladb/
scylladb/

Share Slideshare

LinkedIn
Facebook
Twitter

Embed

Size (px)

Show related Slideshows at end

WordPress Shortcode

Link

Share
Email

2024 Trend Updates: What Really Wor... by Search Engine Jou... 1063109 views
Storytelling For The Web: Integrate... by Chiara Aliotta 981811 views
Artificial Intelligence, Data and C... by OECD Directorate ... 923520 views
How to Leverage AI to Boost Employe... by SocialHRCamp 392340 views
2024 State of Marketing Report – by... by Marius Sescu 221896 views
Everything You Need To Know About C... by Expeed Software 237729 views

View on Slideshare

1 of 38 Ad

View on Slideshare

1 of 38 Ad