NoSQL and NewSQL: Tradeoffs between Scalable Performance & Consistency

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

NoSQL and NewSQL
Tradeoffs Between Scalable
Performance & Consistency
Avishai Ish-Shalom

2
A brief history of databases
2
1970s
Mainframes:
inception of the
relational model
1990s
LAN age:
replication, external
...

3
Umbrella term for everything NOT SQL
NoSQL – Not Only SQL
Simplicity Power
K/V stores
“Wide rows”
Document stores
Also, ...

4
Traditional RDBMS had severe scaling limitations
+ Cost
+ Scalability
+ Performance
+ Simplicity, predictability
Why NoS...

5
Distributed relational database with SQL support
+ OLTP workloads
+ Distributed transactions
+ ACID guarantees
NewSQL

6
+ Compatibility, familiar model
+ Better scalability than traditional RDBMS
+ Rich, powerful query language
Why NewSQL?

Data modeling
7
Relationships are hard

8
SQL is based on “relational algebra” (with some deviations)
+ Tables are relations between columns
+ Tables relate to ea...

9
Normalization
Foreign key
SELECT * FROM Companies
JOIN Employees ON
Companies.CompanyID =
Employees.CompanyID WHERE
Comp...

10
+ Keep the data together
+ Minimal constraints on data structure
+ Possible duplication of values
+ Minimal reshaping o...

11
Data models comparison
Normalized Denormalized
Data shaping On the ﬂy, read-time Pre-shape, write-time
Joins On the ﬂy,...

solation - transactions do not impact each other
12
A
C
I
D
ACID
tomicity - no intermediate states. Transactions complete ...

13
ACID is about concurrency, mutability
+ Pessimistic model
+ Predates distributed databases
+ Designed for monolithic da...

14
+ Poorly deﬁned and understood (A Critique of ANSI SQL Isolation Levels)
+ Still allows for anomalies (unless using Ser...

15
There’s a tradeoff between availability and consistency
+ Normally, Latency/Consistency tradeoff
+ Trade offs, not dich...

NoSQL – By availability vs consistency
16
Pick Two
Availability
Partition Tolerance
Consistency

Poll time!
17

18
+ ACID cannot be available (for isolation > READ COMMITTED)
+ CAP doesn’t actually apply to transactions (HAT not CAP)
...

(New)SQL is about semantics
NoSQL is about dynamics
19

20
Semantics – the “what”
+ What data
+ What shape
+ Schema
Focus on query power, integrity
Semantics vs dynamics
Dynamics...

21
NewSQL
+ SQL abstracts over scale
+ No semantics for
yield/harvest
+ Joins conﬂicts with sharding
+ Consistency elevate...

22
NewSQL
+ Ad-hoc
+ Mix reads and writes
+ Let the database worry
Performance hints, but limited
Query semantics
NoSQL
+ ...

23
Performance
YCSB workload A: 50% reads, 50% updates; high contention

24
Performance
YCSB workload D: 95% reads, 5% inserts; no contention

25
Performance
YCSB workload F: 50% reads, 50% read-modify-write updates; pseudo transactional

26
+ NoSQL designed for simple, fast queries
+ Consistency is expensive
+ Contention is expensive
+ Complex query processi...

27
Poll time!

28
NewSQL crunches the CPU
+ Compute results from storage
+ On the ﬂy - each query
+ Indexed writes
+ Constraints veriﬁcat...

20 years of hardware
evolution in 2 slides
29

30
RAM price by year

31
35 years of microprocessor trend data

What happened?
32
+ Per thread performance plateaued
+ Cores: 1 => 256
+ RAM: 2GB => 2TB
+ Disk space: 10GB => 10TB
+ Disk...

We have lots of cores,
disks, machines
33
But can we use them?

34
Three major strategies:
+ Larger/faster hardware
+ Replicate data (increase throughput => CAP/PACELC)
+ Shard data (inc...

35
Coherency,
consensus,
synchronization
Row/partition
contention,
locks,
transactions
Universal Scalability Law

Avoid cross shard/replica
interactions at all costs
36

37
+ In reality there are very few cases requiring atomic transactions
+ No, ﬁnances mostly don’t need transactions - e.g....

38
NewSQL
+ Generic data model
+ Strong consistency
+ Transactions
+ Limited scalability
+ Slow
Choosing between apples an...

United States
2445 Faber St, Suite #200
Palo Alto, CA USA 94303
Israel
Maskit 4
Herzliya, Israel 4673304
www.scylladb.com
...

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... 1024759 views
Storytelling For The Web: Integrate... by Chiara Aliotta 934642 views
Artificial Intelligence, Data and C... by OECD Directorate ... 848885 views
How to Leverage AI to Boost Employe... by SocialHRCamp 355199 views
2024 State of Marketing Report – by... by Marius Sescu 202124 views
Everything You Need To Know About C... by Expeed Software 223622 views

View on Slideshare

1 of 39 Ad

View on Slideshare

1 of 39 Ad