Transcript Document
Big Data Without Big Change
SemTech West 2012
Michael Lang
Revelytix
Discussion Points
Review the RDBMS, ETL, and data warehouse
data management paradigms
Compare those paradigms to data
virtualization and Big Data
Propose “Bigger Data” in support of radically
better analytic capability
The Last Forty Years
In 1970, E.F. Codd, with the IBM Research Laboratory in San Jose,
California, wrote a paper published in ACM,
“A Relational Model of Data for Large Shared Data Banks”
Codd wrote, “The problems treated here are those of data
independence – the independence of application programs from
the growth in data types and changes in data representation...”
This paper set in motion the architecture for data management
systems for the next forty years. These systems are known as
relational database management systems (RDBMS)
The Last Forty Years
Siloed Information Management Systems
–
All data in a single shared databank
–
Rigid schemas
–
Data and metadata are different types of things
–
Query processor only knows about its local data
expressed in a fixed schema
–
Excellent ACID / CRUD capability
The Age of
Virtualization
DIMS
Distributed Information
Management System
Virtualization
Hardware and operating system virtualization
became available in 2004 and brought great
value to IT infrastructure
–
Cloud-based deployment
–
Extreme flexibility
–
Efficient use of hardware resources
–
Independence from operating systems
Leading to an enormous ROI for large enterprises
EDM
Hardware virtualization did not help with the
problems associated with Enterprise Data
Management
–
Data remains distributed over many silos, even in
cloud-based environments
–
Meaning of data in independent silos is still obscure
–
Schema are still disparate
Data Virtualization
The advent of RDF, OWL, and SPARQL have
created the technical foundation for building a
completely virtualized data infrastructure
–
All information can be managed in the same data
model
–
Any domain can be described at the schema level
–
SPARQL provides a distributed query and
transformation language
–
R2RML provides mappings from native schema to
RDF schema
–
Standards-based data virtualization is here to stay
Data Virtualization
This paradigm assumes data is completely
distributed, and that anyone/anything should
be able to find it and use it
–
RDF is the data model
–
OWL is the schema model
–
SPARQL is the query language
–
URI provide a unique identifiers
–
URL provides the location
Data Abstraction
A RDBMS is an abstraction layer above an
OS-based file systems
–
Made it vastly simpler to work with local data
Data Virtualization is an abstraction layer above
multiple RDBMS and/or other sources of data
–
vastly simpler to work with distributed data
–
Distributed Information Management System
Caveats
Data virtualization technologies are not as
performant as locally managed data
Data virtualization depends on sophisticated
transformation of complex and unstructured
data
Bigger Data: Hadoop
and Virtual Data
DIMS
Distributed Information
Management System
NoSQL / Big Data
Another seminal paper:
Copyright 2003 ACM
“The Google File System”
Sanjay Ghemawat, Howard Gobioff, and Shun-Tak Leung
• These data processing systems are highly distributed but,
…
• Each NoSQL database is a “large shared databank”
• Data cannot be combined for analytics across NoSQL
databases
• NoSQL is an evolutionary step in data storage; it is not a
paradigm shift in information management
Big Data
Hadoop is an excellent technology to use for
transforming data of varying structures to
formats useful for analytics
Hadoop also excels at handling very large
amounts of disparate data
Virtual data needs a place to be materialized
Data Virtualization technologies provide a
common structure and access methodology for
disparate sets of data
Data Virtualization
SPARQL
(data output)
Rules
(RIF)
Inferred Data
SPARQL
(data input)
SPARQL
(data input)
SPARQL
Data Validation
& Analysis
Domain
Ontology
SPARQL
SPARQL
Mappings
(R2RML)
RDB Schema
(Source
Ontology)
Mappings
(R2RML)
RDB
RDB
RDB Schema
(Source
Ontology)
Hadoop
The RDF-based technology implementing a virtual
data infrastructure is useful for Hadoop data
transformations using MapReduce
–
All of the disparate data sets in a Hadoop cluster can
be organized with a common set of semantics
provided by an R2RML map and a Domain Ontology
–
Data transformations are made using a series of
MapReduce jobs
–
ETL becomes ELT
ELT
Extract, Load, and Transform is a fundamentally
new paradigm facilitating enterprise analytics
–
Data can be loaded in its native formats and
structures
–
Transformation activities take place after the data is
loaded into a Hadoop cluster
–
Hadoop and MapReduce are excellent technologies
for data transformations at scale
Query Engine = Transformation Engine
Need to transform structure
–
Relational -> RDF
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HDFS/HBase -> Tuples
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Merge data from multiple sets (federate)
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Basic query processing: join, aggregation, etc
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Execute arbitrary user-defined analytical functions (UDFs)
Revelytix query engines already do these
–
Spinner – federation, query processing, Hadoop-to-tuples
–
Spyder – relational-to-RDF, query processing
Transforming Data in Hadoop
Source Data
Hadoop/Cloud Infrastructure
Data
Triples
Load,
Index
Relational
Database
Triples
HDFS
Files
Extract
HBase
Transform
The big win is to leave the data in situ, and define networked pipelines of
transformations to move data through various processing stages.
Relational
Database
Distributed Pipelined Processing
Processing Pipeline
Design
Configure execution environments for parts of pipeline
local
Dataflow
Pipeline
Definition
X1
X6
a
X6
b
cloud
S1a
S1b
S6
S5
X5
Execution
X8
Query
S8
S4
S7
‘endpoints’
S2
D2
S3
D3
F1
Data Flow
T
Mix of materialized and
virtual data sets…
inter-linked by a set of
transformations
D1
T
T
T
T
T
Query Processing in
Hadoop
Hadoop and SPARQL
Once the data sets have been transformed to a
common set of semantics, SPARQL queries can
be executed as a set of distributed MapReduce
jobs
We must know the relationships between data
sets
The descriptions of the relations need to be
available at query time
Query Execution in the Cloud
Hadoop/Cloud Infrastructure
Data
Query
Client
Query
Processor
Query
Query
Query
Query
Processor
Processor
Processor
Processor
HDFS
Files
HBase
Query processor is shipped to all Hadoop nodes for parallel
processing, using the Hadoop MapReduce framework.
Query Processing
Hadoop/Cloud Infrastructure
Data
Spinner
•
•
•
Spinner
HDFS
Files
Hadoop
Adapter
Hadoop/Cloud Infrastructure
HBase
Data
HDFS
Spyder
Hadoop
Adapter
Files
HBase
Query processing can be done locally, remotely (in cloud), or mix
Many types of transformations can be done
•
Basic query processing (SPARQL or SQL)
•
Relational to graph (R2RML) transformations
•
Federation over multiple sources or data sets
•
Hadoop HDFS-to-Tuple and HBase-to-Tuple transformations
We can plan and optimize across all these for maximum performance
Hadoop and RIF
Once the data sets have been transformed to a
common set of semantics, RIF rules can be
executed as a set of distributed MapReduce
jobs
–
Inference
–
Classification
–
Validation
–
Compliance
Why Use
Hadoop?
Enable access to large volumes of data
Warehouse-style access
Enable a ‘processing pipeline’ in the cloud
Push processing into Map-Reduce infrastructure
Parallelize query execution
–
Extreme scalability
Architectural flexibility
Future Directions
27
Hadoop and Solr
Integration between Hadoop, Data
Virtualization, and Solr provides massively
scalable faceted search
–
The common set of semantics, applied over
disparate unstructured data sets provides a
powerful paradigm for searching with facets over
massive amounts of data
What Are We Offering?
Seamless integration of virtual data and Hadoop
Linkage (relationships) between data sets, yielding…
–
Provenance/traceability/lineage
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Metadata management and data visibility/understanding
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Powerful analytics infrastructure
Common data model, enabling…
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Mixing of relational and graph-based data
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Mixing of SQL and SPARQL queries
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Access to all cloud-based data
Optimization across heterogeneous data systems
The Shift is On
Distributed Information
Management System
DIMS is available now
Questions
Revelytix.com for much additional information
Thank You