This document discusses Continuent Tungsten, a product that provides high availability, performance scaling, and data management for MySQL database clusters. It introduces Continuent and describes how Tungsten uses master-slave replication across multiple database servers to provide high performance, high availability, and transparent read/write access to applications. The document also provides examples of how Tungsten handles transactions, load balancing, failover, and rolling upgrades without downtime.

1. ©Continuent 2014
Harnessing the Power of
Master/Slave Clusters for Data-
Driven Business on MySQL
Robert Hodges, CEO
Giuseppe Maxia, Director of QA

2. ©Continuent 2014 2
Introducing Continuent

3. ©Continuent 2014
Introducing Continuent
3
• The leading provider of clustering and
replication for open source DBMS
• Our Product: Continuent Tungsten
• Clustering - Commercial-grade HA, performance
scaling and data management for MySQL
• Replication - Flexible, high-performance data
movement

4. ©Continuent 2014
Quick Continuent Facts
• Largest Tungsten installation by data volume
processes over 800 million transactions per
day on 225 terabytes of relational data
• Largest installation by transaction volume
handles up to 8 billion transactions daily
• Wide variety of topologies including MySQL,
Oracle, Vertica, and Hadoop in production
• Cross-site topologies widely deployed
4

5. ©Continuent 2014©Continuent 2014
Continuent Tungsten Customers
5
1

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Too Good to Be True

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The Dream: multiple, active DBMS
servers with identical data
7
Server A
Server B
Server C
Transparent
read/write
to any server
Updates
propagated
immediately
High
Performance
High
Availability

8. ©Continuent 2014
Multi-Master Clusters in Action: Galera
8
Group
Ordering and
Delivery
Server A
Server B
Server C
foo
pk=1, v=5
foo
pk=6, v=25
foo
pk=1, v=6
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25

9. ©Continuent 2014
Synchronous Optimistic Locking
9
Group
Ordering and
Delivery
Server A
Server B
Server C
foo
pk=1, v=5
foo
pk=6, v=25
foo
pk=1, v=6
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25
[1] pk=1, v=6
[2] pk=1, v=5
[3] pk=6, v=25
COMMIT
COMMIT
DEADLOCK

10. ©Continuent 2014
Trouble in Paradise
• Transaction failures due to conflicts
• Operations like SELECT FOR UPDATE not
supported
• Slow writes due to synchronous messaging
• Large transactions lock system/cause failures
• Unstable cross-site replication
10

11. ©Continuent 2014
Can Master/Slave Offer Same
Benefits?
11
Server A
Server B Server C
Updates
propagated
immediately?
High
Performance?
High
Availability?
Transparent
read/write
to any server?

12. ©Continuent 2014 12
Tungsten Master/Slave Clusters

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Tungsten Database-as-a-Service
13
Tungsten clusters combine off-
the-shelf open source DBMS
servers into data services with:
!
• 24x7 data access
• Scaling of load on replicas
• Simple management commands
!
...without app changes or data
migration
Amazon
US West
apache
/php
GonzoPortal.com
Connector Connector

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Cluster Architecture
14
Application
Tungsten Connector
Application
Tungsten Connector
Replicator
Db2
Replicator
Db3Db1
Replicator
Slave SlaveMaster
Manager Manager Manager
MonitoringandControl
MonitoringandControl
Data Service: sjc

15. ©Continuent 2014
Tungsten Connector Basics
• Any MySQL client can connect
• Initiates connections using JDBC
15
App Native
protocol
!
COM_QUERY
COM_INIT_DB
COM_DROP_DB
Connector

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Tungsten Connector Basics
• Pass-through operation after connection
• Full transparency & low overhead for clients
16
App
Protocol packet
COM_QUERY
select * from t
Connector
Protocol packet
OK
ResultSet Rows:1

17. ©Continuent 2014
SmartScale Session Load Balancing
17
App
Connect/Write
Connector
Transaction
History Log
Slave
replay
position
Session x
Session y
Slave
DBMS
Master
DBMS
Slave
DBMS
Initial Write

18. ©Continuent 2014
SmartScale Session Load Balancing
18
App
Read
Connector
Transaction
History Log
Slave
replay
position
Session x
Session y
Slave
DBMS
Master
DBMS
Slave
DBMS
Read from master
NO read from slave!

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SmartScale Session Load Balancing
19
App
Read
Connector
Transaction
History Log
Slave
replay
position
Session x
Slave
DBMS
Master
DBMS
Slave
DBMS
Read from master
Read from slave

20. ©Continuent 2014
Connectivity Example
20
Tungsten Connector Tungsten Connector
Db2 Db3Db1
SlaveMasterSlave
(SmartScale) (Strict Consistency)

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Demo: Transparent
Connectivity to Replicas

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Transaction Scaling with
Master/Slave Clusters

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Understanding Replication
23
Master
(Transactions + Metadata)
Slave
THL
DBMS
Logs
Replicator
(Transactions + Metadata)
THLReplicator
Download
transactions
via network
Apply using JDBC

24. ©Continuent 2014
Master Replication Service
24
Extract Filter Apply
Stage
Extract Filter Apply
Stage
Pipeline
MySQL
Master
Transaction
History Log
In-Memory
Queue
Slave
ReplicatorsBinlog
tcp/ip

25. ©Continuent 2014
Slave Service with Parallel Apply
25
Extract Filter Apply
Stage
Extract Filter Apply
Stage
Stage
Pipeline
Transaction
History Log
Parallel
Queue
Slave
DBMS
Extract Filter Apply
Extract Filter Apply
Extract Filter Apply
Master
Replicator
tcp/ip

26. ©Continuent 2014
Understanding Transaction Loads
26
Large
TransactionsSlow
queries
Reports
Db2 Db3Db1
SlaveMasterSlave
Small
Transactions

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Demo: Scalable
Transaction Processing

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Master/Slave Clustering
Across Regions

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Primary/Disaster Recovery Clustering
29
App Server
+ Connector
App Server
+ Connector
Master Slave
San Jose NYC

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Further Cross-Site Topologies
30
Data Warehouse
All
Masters
Fan-In

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Failover and Maintenance

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Automatic Failover
32
Application
Tungsten Connector

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Automatic Failover
33
Application
Tungsten Connector
1. Detect non-
responsive
master
2. Halt master connections

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Automatic Failover
34
Application
Tungsten Connector
3. Select most advanced
slave and wait for pending
transactions to apply

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Automatic Failover
35
Application
Tungsten Connector
4. Promote to master,
reconfigure slave(s), and
re-enable connections

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Automatic Failover
36
Application
Tungsten Connector
5. Recover failed master

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Rolling MySQL maintenance
• Task: change the innodb log file size
• Problem: it requires a database server restart
• Constraint: we do not want to restart
• Solution: rolling maintenance
• shun node2 (slave) - do maintenance - put node online
• shun node3 - do maintenance - put node online
• promote node2 to master
• shun node1 - do maintenance - put node online
• promote again node1 to master
37

38. ©Continuent 2014
Rolling MySQL Maintenance
38
Final UpgradeSwitchSlave Upgrade Slave Upgrade
• Shun slave 1,
run upgrade,
and return to
cluster.
Discard and
recover on
failure
• Upgrade old
master.
Cluster
schema is now
fully upgraded
• Repeat for
additional
slave(s)
• Switch
master to
promote an
upgraded
slave

39. ©Continuent 2014 39
Demo: Zero-Downtime
Upgrade and Failover

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Wrap-Up

41. ©Continuent 2014
Master/Slave Performs Very Well!
41
Server A
Server B Server C
Updates
propagated
without cost
to applications
Very High
Performance
Very High
Availability
Transparent
connectivity
with full SQL
semantics

42. ©Continuent 2014
In Conclusion: Tungsten Offers...
• Transparent access to a highly available cluster of
off-the-shelf MySQL replicas
• High performance transaction processing regardless
of cluster size or distance between nodes
• Zero-downtime maintenance and upgrade of DBMS
and applications
42

43. ©Continuent 2014
www.continuent.com
Follow us on Twitter @continuent
!
Tungsten Replicator:
http://code.google.com/p/tungsten-replicator
Our Blogs:
http://scale-out-blog.blogspot.com
http://datacharmer.org/blog
http://www.continuent.com/news/blogs
http://flyingclusters.blogspot.com/
560 S. Winchester Blvd., Suite 500
San Jose, CA 95128
Tel +1 (866) 998-3642
Fax +1 (408) 668-1009
e-mail: sales@continuent.com