Saturday, 27 February 2016

Oracle Database Cloud Service vs Amazon Relational Database Service

How to compare Oracle’s Database Public Cloud with Amazon’s Relational Database Service (RDS) for enterprise usage? Let us have a look.

Oracle’s Database has 4 editions: Personal Edition, Express Edition (XE): free of charge and used by very small businesses and students, Standard Edition (SE): light version of Enterprise Edition and purpose designed to lack most features needed for running production grade workloads and Enterprise Edition (EE): provides the performance, availability, scalability, and security required for mission-critical applications.

In the comparison in this post, we will evaluate Oracle and Amazon in relation to the Enterprise Edition of Oracle’s database.

Oracle Database Cloud Service vs Amazon Relational Database Service

Oracle Public Database Cloud consists of 4 DB Cloud offerings: DBaaS, Virtual Image, Schema Service and Exadata Service. Here are few characterizations:

– Oracle supports Exadata, RAC & all DB options
– Simple pricing structure with published costs representing actual costs (unlimited I/Os, etc.)
– Hourly, Monthly & Annual pricing options
– Lowest cloud storage pricing across all major IaaS vendors

Amazon RDS for Oracle Database supports two different licensing models – “License Included” and “Bring-Your-Own-License (BYOL)”. In the “License Included” service model, you do not need separately purchased Oracle licenses. Here are few characterizations:

– Enterprise Edition supports only db.r3.large and larger instance classes, up to db.r3.8xlarge
– Need to choose between Single-AZ (= Availability Zone) Deployment and Multi-AZ Deployment
– For Multi-AZ Deployment, Amazon RDS will automatically provision and manage a “standby” replica in a different Availability Zone (prior to failover you cannot directly access the standby, and it cannot be used to serve read traffic)
– Only 2 instance types support 10 Gigabit network: db.m4.10xlarge and db.r3.8xlarge
– Amazon RDS for Oracle is an exciting option for small to medium-sized clients and includes Oracle Database Standard Edition in it’s pricing
– Several application with limited requirements might find Amazon RDS to be a suitable platform for hosting a database
– As the enterprise requirements and resulting degree of complexity of the database solution increase, RDS is gradually ruled out as an option

So, here is high level comparison:

Oracle Database Cloud Service vs Amazon Relational Database Service


Notes:

– Oracle’s price includes the EE license with all options
– Amazon AWS is BYOL for EE
– Prices above are based on the EU (Frankfurt) region
– Amazon’s Oracle database hour prices vary from $0.290 to $4.555 for Single AZ Deplyoments and from $0.575 to $9.105 for Multi-AZ Deployments
– Oracle’s database hour prices vary from $0.672 to $8.569

So, Amazon RDS is not an option if you need any of the following: Real Application Clusters (RAC), Real Application Testing, Data Guard / Active Data Guard, Oracle Enterprise Manager Grid Control, Automated Storage Management, Database Vault, Streams, Java Support, Locator, Oracle Label Security, Spatial, Oracle XML DB Protocol Server or Network access utilities such as utl_http, utl_tcp, utl_smtp, and utl_mail.

Tuesday, 16 February 2016

ASM Proxy: New Instance Type in Oracle 12c

Prior to Oracle Database 12c, an ASM instance ran on every node in the cluster and ASM Cluster File System (ACFS) Service on a node connected to the local ASM instance running on the same host to fetch the required metadata. If the ASM instance on a node were to fail, then ACFS file systems could no longer be accessed on that node.

With introduction of Flex ASM in Oracle 12c, hard dependency between ASM and its clients has been relaxed and only a smaller number of ASM instances need run on a subset of servers in a cluster. In such a scenario, in order to make ACFS services available on nodes without an ASM instance, a new instance type has been introduced by Flex ASM: the ASM-proxy instance which works on behalf of a real ASM instance. ASM Proxy instance fetches the metadata about ACFS volumes and file systems from an ASM instance and caches it. If ASM instance is not available locally, ASM proxy instance connects to other ASM instances over the network to fetch the metadata. Additionally, if the local ASM instance fails, then ASM proxy instance can failover to another surviving ASM instance on a different server resulting in uninterrupted availability of shared storage and ACFS file systems.