ebab7d0da53c51438720d60c6e2e467c - /page/wikibook/entry.mu

Micron Document

Livres et Wikis | Archives | Info

🔍Search

Oracle NoSQL Database

22.3 KB · ⇊ 7 parts · ⤓ Micron 22.3 KB · ⤓ HTML 52.2 KB

layout: Wide · Narrow · Centered

──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

top

Oracle NoSQL Database is a NoSQL-type distributed key-value database

from Oracle Corporation.cite-ref-1[1]cite-ref-2[2]cite-ref-iw-3-0[3]cite-ref-4[4] It provides transactional semantics

for data manipulation, horizontal scalability, and simple administration

and monitoring.

Oracle NoSQL Database Cloud Service is a managed cloud service for

applications that require low latency, flexible data models, and elastic

scaling for dynamic workloads.

Developers focus on application development and data store requirements

rather than managing back-end servers, storage expansion, cluster

deployments, topology, software installation/patches/upgrades, backup,

operating systems, and availability. NoSQL database scales to meet

dynamic application workloads and throughput requirements.

Users create tables to store their application data and perform database

operations. A NoSQL table is similar to a relational table with

additional properties including provisioned write units, read units, and

storage capacity. Users provision the throughput and storage capacity in

each table based on anticipated workloads. NoSQL Database resources are

allocated and scaled accordingly to meet workload requirements. Users

are billed hourly based on the capacity provisioned.

NoSQL Database supports tabular model. Each row is identified by a

unique key, and has a value, of arbitrary length, which is interpreted

by the application. The application can manipulate (insert, delete,

update, read) a single row in a transaction. The application can also

perform an iterative, non-transactional scan of all the rows in the

database.

Contents

• Licensing

• Main features

• Architecture

• Administration and system monitoring

• Fault tolerance

• Database features

• Integration

• Oracle integration

• Enterprise security

• Performance

• See also

• References

Licensing

Oracle Corporation distributes the Oracle NoSQL Database in three

editions:

• Oracle NoSQL Database Server Community Edition under an

Apache License, Version 2.0

• Oracle NoSQL Enterprise Edition under the Oracle Commercial License

• Oracle NoSQL Basic Edition

Oracle NoSQL Database is licensed using a freemium model: open-source

versions of Oracle NoSQL Community Edition are available, but end-users

can purchase additional features and support via the Oracle Store.cite-ref-5[5]

Oracle NoSQL Database drivers,cite-ref-6[6] licensed pursuant to the

Apache 2.0 License, are used with both the community and enterprise

editions.cite-ref-7[7]

Main features

Architecture

Oracle NoSQL Database is built upon the Oracle Berkeley DB Java Edition

high-availability storage engine. It adds services to provide a

distributed, highly available key/value store, suited for large-volume,

latency-sensitive applications.cite-ref-8[8]

Sharding and replication

Oracle NoSQL Database is a client-server, sharded, shared-nothing

system. The data in each shard are replicated on each of the nodes that

comprise the shard. The major key for a record is hashed to identify the

shard that the record belongs to. Oracle NoSQL Database is designed to

support changing the number of shards dynamically in response to

availability of additional hardware. If the number of shards changes,

key-value pairs are redistributed across the new set of shards

dynamically, without requiring a system shutdown and restart. A shard is

made up of a single electable master node to serve read and write

requests, and several replicas (usually two or more) that can serve read

requests. Replicas are kept up to date using streaming replication. Each

change on the master node is committed locally to disk and also

propagated to the replicas.

High availability and fault-tolerance

Oracle NoSQL Database provides single-master, multi-replica

database replication.cite-ref-9[9] Transactional data is delivered to all replica

nodes with flexible durability policies per transaction. In the event

the master replica node fails, a consensus-based PAXOS-based automated

fail-over election process minimizes downtime. As soon as the failed

node is repaired, it rejoins the shard, updated and then becomes

available for processing read requests. Thus, Oracle NoSQL Database

applications can tolerate failures of nodes within a shard and also

multiple failures of nodes in distinct shards.

Proper placement of masters and replicas on server hardware (racks and

interconnect switches) by Oracle NoSQL Database is intended to increase

availability on commodity servers.

Transparent load balancing

Oracle NoSQL Database Drivercite-ref-10[10] partitions the data in real time and

evenly distributes it across the storage nodes. It is network topology

and latency-aware, routing read and write operations to the most

appropriate storage node in order to optimize load distribution and

performance.

Administration and system monitoring

Oracle NoSQL Database's administration service can be accessed from a

web console or a command-line interface. This service supports

functionality such as the ability to configure, start, stop and monitor

a storage node, without requiring configuration files, shell scripts, or

explicit database operations. It allows Java Management Extensions (JMX)

or Simple Network Management Protocol (SNMP) agents to be available for

monitoring. This allows management clients to poll information about the

status, performance metrics and operational parameters of a storage node

and its managed services.cite-ref-11[11]

Elastic configuration

"Elasticity" refers to dynamic online expansion of the deployed

cluster.cite-ref-12[12] Adding storage nodes increases capacity, performance and

reliability. Oracle NoSQL Database includes a topology planning feature,

with which an administrator can modify the configuration of a NoSQL

database while the database is online. The administrator can:

• Increase data distribution: by increasing number of shards in the

cluster, which increases write throughput.

• Increase replication factor: by assigning additional replication nodes

to each shard, which increases read throughput and system availability.

• Rebalance data store: by modifying the capacity of storage nodes, the

system can be rebalanced, re-allocating replication nodes to storage

nodescite-ref-13[13] as appropriate.

Administrators can move replication nodes and/or partitions from

over-utilized nodes onto underutilized storage nodes or vice versa.

Multi-zone deployment

Oracle NoSQL Database supports multiple zones to intelligently allocate

replication of processes and data, in order to improve reliability

during hardware, network and power-related failure modes. The two types

of zones are: primary zones that contain nodes that can serve as masters

or replicas and are typically connected by fast interconnects. Secondary

zones contain nodes that can only serve as replicas. Secondary zones can

be used to provide low latency read access to data at a distant

location, or to offload read-only workloads such as analytics, report

generation and data exchange for improved workload management.

JSON data format

Oracle NoSQL Database supports Avrocite-ref-14[14] data serialization, which

provides a compact, schema-based binary data format. Schemas are defined

using JSON. Oracle NoSQL Database supports schema evolution.

Configurable Smart Topology System administrators indicate how much

capacity is available on a given storage node, allowing more capable

nodes to host multiple replication nodes. Once the system knows about

the capacity for the storage nodes in a configuration, it automatically

allocates replication nodes intelligently. This is intended for better

load balancing, better use of system resources and minimizing system

impact in the event of storage node failure. Smart Topology supports

data centers, ensuring that a full set of replicas is initially

allocated to each data center.

Online rolling upgrade

Oracle NoSQL Database provides facilities to perform a rolling upgrade,

allowing a system administrator to upgrade cluster nodes while the

database remains available.cite-ref-15[15]

Fault tolerance

Oracle NoSQL Database is configurable to be either C/P or A/P in

CAP.cite-ref-16[16] In particular, if writes are configured to be performed

synchronously to all replicas, it is C/P in CAP i.e. a partition or node

failure causes the system to be unavailable for writes. If replication

is performed asynchronously, and reads are configured to be served from

any replica, it is A/P in CAP i.e. the system is always available, but

there is no guarantee of consistency.

Database features

Table data model

Release 3.0 introduced tabular data structure, which simplifies

application data modeling by leveraging existing schema design concepts.

Table model is layered on top of the distributed key-value structure,

inheriting all its advantages and simplifying application design by

enabling seamless integration with familiar SQL-based applications

Secondary index

Primary key only based indexing limits the number of low latency access

paths. Sometimes applications need a non-primary-key based paths to

support specific application requirements. OND supports secondary index

on any value field.cite-ref-17[17]

Large object support

Oracle NoSQL Database EE Stream based APIs allow reading and writing

large objects (LOBs) such as audio and video files, without having to

materialize the entire file in memory. This is intended to decrease the

latency of operations across mixed workloads of objects of varying

sizes.cite-ref-18[18]

ACID compliant transaction

Oracle NoSQL Database provides ACID compliant transactions for full

create, read, update and delete (CRUD) operations, with adjustable

durability and consistency transaction guarantees. A sequence of

operations can operate as a single atomic unit as long as all the

affected records share the same major key path.cite-ref-19[19]

Integration

Oracle NoSQL Database includes support for Java, C, Python, C# and REST

APIs. These allow the application developer to perform CRUD operations.

These libraries include Avro support, so that developers can serialize

key-value records and de-serialize key-value records interchangeably

between C and Java applications.cite-ref-20[20]

Oracle RESTful Services

Oracle NoSQL Database supports Oracle REST Data Services (ORDS).cite-ref-21[21]

This allows customers to build a REST-based application that can access

data in either Oracle Database or OND.

GeoJSON

Supports spatial queries on RFC7946 compliant GeoJSON data. Spatial

functions and indexing for GeoJSON data are supported.

Apache Hadoop

KVAvroInputFormat and KVInputFormatcite-ref-22[22] classes are available to read

data from OND natively into Hadoop MapReduce jobs. One use for this

class is to read NoSQL database records into Oracle Loader for

Hadoop.cite-ref-23[23]

Oracle integration

Oracle Big Data SQL and Hive

Oracle Big Data SQL is a common SQL access layer to data stored in

Hadoop, HDFS, Hive and OND. This allows customers to query Oracle NoSQL

Data from Hive or Oracle Database. Users can run MapReduce jobs against

data stored in OND that is configured for secure access. The latest

release also supports both primitive and complex data types

Oracle Database

Oracle NoSQL Database EE supports external table allows fetching Oracle

NoSQL data from Oracle database using SQL statements such as Select,

Select Count(*) etc. Once NoSQL data is exposed through external tables,

one can access the data via standard JDBC drivers and/or visualize it

through enterprise business intelligence tools.

Other Oracle products

Oracle Event Processing (OEP) provides read access to Oracle NoSQL

Database via the NoSQL Database cartridge. Once the cartridge is

configured, CQL queries can be used. Oracle Semantic Graph includes a

Jena Adapter for Oracle NoSQL Databasecite-ref-24[24] to store large volumes of RDF

data (as triplets/quadruplets). This adapter enables fast access to

graph data stored in OND via SPARQL queries. Integration with

Oracle Coherence allows OND to be used as a cache for Oracle Coherence

applications, allowing applications to directly access cached data from

OND.

Enterprise security

Oracle NoSQL Database EE supports OS-independent, cluster-wide

password-based user authentication and Oracle Wallet integration and

enables greater protectioncite-ref-25[25] from unauthorized access to sensitive

data. Additionally, session-level Secure Sockets Layer (SSL) encryption

and network port restrictions improve protection from network intrusion.

Performance

The Oracle NoSQL Database team has worked with several key Oracle

partners, including Intel and Cisco,cite-ref-26[26] performing

Yahoo! Cloud Serving Benchmarks (YCSB) on various hardware

configurations, and published its results. For example, in 2012 Oracle

reported that Oracle NoSQL Database exceeded 1 million mixed YCSB

Ops/Sec.cite-ref-27[27]