An introduction to Google Spanner

1
Google Spanner

• What is it ?
• How does it work ?
• Future Scale
• Architecture
• Terms

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2
Google Spanner What is it ?

• The world's largest distributed database
• Internally used by Google
• Has a true time API to avoid latency problems
• Supports Google's Advertising business
• It is fault tolerant to large scale outages
• Offers very high availability and latency
• Aiming for 99 and 50 ms

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3
Google Spanner How does it work ?

• Has a true time API
• Atomic clocks
• GPS Clocks
• Locally determine accurate time
• No need for global time sync
• One single global name space
• Data stored globally via directory namespace
• Uses a Paxos algorithm

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4
Google Spanner Scale

• How big is it , what are they aiming for ?
• Aiming for 107 machines
• 1013 directories
• 1018 bytes of storage
• 1000's of storage locations
• 109 clients
• Current data centres up to 100 ms apart

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5
Google Spanner Architecture

• A zonemaster has 100's of spanservers
• Zonemasters assign data to spanservers which
  serve clients
• Location proxies help clients locate spanservers
• Universe master displays zone status information
• Placement driver automates data zone movement

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6
Google Spanner Architecture
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7
Google Spanner Architecture

• Each spanserver manages 100's of tablets
• Each spanserver has a paxos machine
• Paxos machine supports replication
• Lead replica has lock table
• Lead replica has transaction manager
• For transactions over multiple paxis groups
• 2 phase commit used
• For control of transactions
• Coordinator leader
• Coordinator slaves used

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8
Google Spanner Terms

• NewSQL
• A modern RDBMS that scales like NoSQL but offers
  OLTP ACID guarantees
• BigTable
• Google's storage system built on GFS
• Google F1
• Google RDBMS for the Adwords system
• Paxos
• An algorithm for determining concensus in a
  network of unreliable processors

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9
Google Spanner Terms

• RDBMS
• Relational Database Management System
• NoSQL
• A highly optimized database for large storage
  volumes, it offers a less constrained consistency
  model than traditional rdbms's
• ACID
• ACID (Atomicity, Consistency, Isolation,
  Durability) is a set of properties that guarantee
  that database transactions are processed reliably
• OLTP
• Online transaction processing

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.co.nz
10
Google Spanner Terms

• Time Synchronisation
• The coordination of events to operate a system in
  unison
• Global Consistency
• Ensuring global users have a consistent view of
  data
• Atomic clock
• Clocks based upon atomic physics principles
• GPS clock
• Clocks that use GPS to determine time from
  multiple satellite atomic clocks

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.co.nz
11
Contact Us

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• www.semtech-solutions.co.nz
• info_at_semtech-solutions.co.nz
• We offer IT project consultancy
• We are happy to hear about your problems
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• To solve your problems