Oracle databases to Azure - Data Management and Innovation at same place

Keeping focus on Data Strategy and culture to meet operational excellence with innovation , I would like to share a key component of Digital Transformation and Cloud Migrations. Lots of customers I come across, face a a very critical task of modernization applications which uses Oracle as backend . Oracle being one of the top RDBMS ruled the market for years and over all these years stored massive data and business logic on them . They became so big and important that many are really scared to disturb these systems. Many of legacy apps are just sitting on prem because they don't have visible modernization plans for these .

In this article I will try to take you on a journey of possible paths for this migration. Azure being one of the top cloud solution provider also provides you with variety of options in database . The following decision tree can be used to choose path of your target new modernize DB solution . Oracle Cloud and Azure are offering a strong platform as well , you can find OCI Related all updated Information here : Azure and OCI Announcement

Lifting and shifting an existing Oracle Database workload requires many important decisions like deciding the networking topology, availability architecture, picking the right compute and storage solution that fits for the customers workload requirements. To begin with the envision phase and making decision that is right for your business and help you to stay compliant, use the following decision tree to design your own path. Hosting Oracle on Azure will provide you with opportunity to modernize and make use of latest data trends like combining your all legacy data , operational data with new data types involved in real time streaming data , social media data as well as IoT Data.

Oracle Licensing Considerations

Working as Azure advisor, I can guarantee one thing we take compliance and regulation very very seriously for all our customers . Hence One of the most frequently question is related to Oracle on Azure Migrations is : Licensing.

Deployment of Oracle applications in Azure is based on a "Bring Your Own License (BYOL)" model. It is assumed that the customer is properly licensed to use Oracle software and has a current support agreement in place with Oracle. Oracle has guaranteed license mobility from on-premises to Azure. But the terms should always be discussed and handshaked with Oracle by the customer.

When calculating Oracle Core Processor license requirements in "Authorized Cloud Environments", the?Oracle Processor Core Factor Table?that is used to calculate the required licenses for a specific HW on premises is not applicable. Instead, the?Licensing Oracle Software in the Cloud Computing Environment?document should be considered. According to this document, for the purposes of licensing Oracle programs in an Authorized Cloud Environment (Azure), customers are required to calculate as follows:

• 2 virtual CPU (vCPU) per 1 Oracle Processor license if hyper-threading enabled
• 1 virtual CPU (vCPU) per 1 Oracle Processor license if hyper-threading not enabled

In addition to that,

• Licensing Metrics include primarily Named User Plus or Processor metric,
• Add-on products such as the Enterprise Options and Management Packs must match the number of licenses of the associated product,
• Functional dependencies may exists among products. Such dependencies must be licensed separately as prerequisite products,

For further information, see the Oracle documentation for?Price List?and the?Database Licensing Documents

Moving Database hosted on Exadata to Azure

Now coming to most costly and important workloads for customer s where they have invested millions in hosting and maintaining their super large or highly critical workloads on Oracle Exadata hardware . You will be surprised to learn that many customers actually do not use all the exadata features for their applications for which they end up paying huge amounts . So its important to do a complete assessment for every workload before starting migration plan to understand what will be the impact and how best it should be handled.

Below is summary of my work done for many exadata migration and key things to keep in mind while planning the migration .

Exadata is a very high performant database offering of Oracle, an Engineered System Appliance with special software and hardware. It offloads a reasonable amount of the data filtering and fetching operations to the storage firmware and hardware hence creates a lot of saving in Read IOPs, Memory usage and CPU. Since it is an HW & SW Appliance, no third-party cloud including Azure does cannot host an Exadata Hardware. However, this won’t stop customers to gain same performance power by utilizing the right Azure VM SKU and Storage and optimizing Oracle Database configuration.

Below it can be seen some of the key features which will not be same when Oracle Database is migrated from Exadata to Azure IaaS.?

Recommendation

It can be suggested to the customers to Capture Performance details with application by disabling Exadata Features to Get a true picture of resource utilization .?Disable some Exadata specific features, if their workload allows it, and run the workload under that settings to capture the statistics in the Active Session History(ASH). With that method the customer can capture extra details which can become very useful for planning any infrastructure other than Exadata including the Azure VM.

These feature changes are stopping offload to cell nodes, disable bloom filters and disable storage indexes. Below commands can be used to accomplish the task:

ALTER SYSTEM SET cell_offload_processing=false;
ALTER SYSTEM SET _bloom_filter_enabled=false;

ALTER SYSTEM SET _kcfis_storageidx_disabled=true;        

Thinking about High Availability

I started my career in early 2000s and always being a heterogeneous Data Consultant gives me advantage on working on best features and compare them side by side to other competitions as well . But I found many people confused Highly scalable solution (RAC) to High available solution . In this section we will focus on High availability solution i.e. Data Guard and GoldenGate solutions from Oracle . Good news is : Its same as you are using today on Prem ! Azure Provides all the help required to achieve desired RTO and RPO.

Disaster recovery and high availability options Help your business to keep doing business—even during major IT outages with the following features:

• DBA’s can configure Oracle Data Guard, Active Data Guard, or Oracle GoldenGate on Azure infrastructure in conjunction with availability zones.
• Customers can utilize Azure Site Recovery to orchestrate and manage disaster recovery for their Oracle Linux VMs in Azure and their on-premises or physical servers.
• Use Oracle Database Cloud Services (Autonomous Database, RAC, Exadata, DBaaS, Single Node) in conjunction with Oracle applications running in Azure.
• Oracle Sharding (available for Oracle DB 12.2 and higher) (explained in below link in detail )
• Oracle Golden Gate bi-directional replication
• The below link is having detail of many possible architecture that you can use on Azure .

Reference architectures for Oracle databases on Azure - Azure Virtual Machines | Microsoft Docs?

Oracle RAC consideration

One of the key feature which any critical Oracle Database implements today on Prem is Oracle RAC . This is a high scalability solution from Oracle . However It's not critical for running the workloads with required RTO and RPO .

Oracle RAC is currently not supported on any third-party cloud. For more details you can check the?Oracle Real Application Clusters (RAC) Support on Third-Party Clouds?document.

Many customers do use Flashgrid and Cloudsimple Technologies to enable RAC on Azure. Follow the blog post?here?for how that is implemented.

?Backup Solution for Oracle on Azure

Nothing gets Complete for any database if we don't have a strong Backup plan available. So , to give familiar feeling to our users , Azure provides a similar experience as well as an advanced way of taking backups for Oracle databases . RMAN backups , Azure Backup , ASR all the great initiatives are available for customer to deign their own backup strategy . Below are key consideration for your design :

• Schedule automatic backups of your Oracle Database with Oracle RMAN &?Azure Backup for application-consistent backups.
• Optionally use?Azure Blob Fuse?to mount a?highly redundant Azure Blob Storage account?and write your RMAN backups to it for added resiliency.
• Use Azure Site Recovery in conjunction with Azure Backups to manage replication, failover and failback of your Azure VMs.
• Backup for Oracle Guidelines - https://techcommunity.microsoft.com/t5/data-architecture-blog/backup-scenarios-for-oracle-on-azure-iaas/ba-p/1554022
• Details with commands for Oracle backup strategies -?Oracle Database in Azure Virtual Machines backup strategies - Azure Virtual Machines | Microsoft Docs

?Oracle Monitoring solutions

Meeting your operational excellency by proactive monitoring and advance monitoring provided by Azure can be combined to design an amazing Monitoring solution for Oracle workloads too . Following can help you to design and customize your own Monitoring or use advanced monitoring features provided by Azure across the platform .

• OEM /Cloud Control from Oracle hosted on VM : https://dbakevlar.com/2019/12/tools-to-monitor-and-work-with-oracle-on-azure/
• Azure VM monitoring can give you all the details related to VM?- https://docs.microsoft.com/en-us/azure/azure-monitor/vm/monitor-vm-azure

?Hope this article helps you to understand basics of migration Oracle to Azure . There are already great suggestions for designing target platform on Azure is available on Microsoft docs but feel free to reach out if you need further help as working on Oracle on Azure is one of my Favorite tasks !