Delphix versus Oracle Snap Clone for Oracle Database Logical Recovery

Background

More frequently than we care to imagine, customers require to be able to recover quickly from scenarios where a database table or data is lost from production either through physical storage corruption or logical mistakes.  Due to the size and complexity of the environments these issues can take a long time to recover from.  Frequently we find that a customer's recovery time objective is challenging to meet.

Many customers use storage replication for HA and DR, however this does not protect against physical storage corruption nor logical mistakes.  Any such corruption would be replicated intact.  Corruption issues can be identified by application users but frequently they are identified much later during backups using RMAN block validation.

An Oracle standby database using database flashback still does not solve the problem because of the time taken to flashback a database and the administration overhead of managing flashback recovery areas.

Customers require a solution that can start up a clone or virtual copy database in minutes, from a specific point in time, to quickly source a database object that can be used to restore the production copy.

Most of the end-to-end recovery time is consumed locating, restoring and recovering the right version of the database.  It is an iterative process to find the most recent non-corrupted database copy.

Both Delphix and Oracle Snap Clone could be viewed as alternative solutions to implement Logical Recovery.

Key Requirements for Logical Recovery

There are three key requirements to implement a logical recovery solution.

1.    Synchronising with Source Database(s)

This solution requires that you have access to a continuous rolling window of backups since you will need to restore database objects (usually tables) from a version of the production database immediately prior to the corruption or fault occurring.  You want to restore the latest good copy of the database object(s).

2.    Provisioning Database Copies

The solution must also be able to provision a database copy to a point-in-time extremely quickly as this may have to be performed several times before the most up-to-date ‘good’ version of the object is located.

3.    Simplicity

The entire recovery process must be automated, easy to use and fast.  Recovery scenarios are stressful events and intuitive ease of use avoids artificial delays during the recovery process itself.

Oracle EM 12c DBaaS Snap Clone for Logical Recovery

1.    Synchronising with Source Database(s)

For continuous synchronisation with a source database Oracle requires a replication method to maintain an up-to-date Test Master from which all clones will be provisioned.

The replication method is typically an Oracle Data Guard physical standby.

The storage on which the standby is running is limited to Sun Storage, NetApp or EMC.  You can use any other storage as long as you have a server running Solaris to create and manage a ZFS file system on that storage.

Challenges

1.     Requires a licensed database server to run the standby database instance

2.     Enough storage for a full physical copy of the source databases

3.     Administration overhead managing the standby database, for example, synchronising nologging operations on the source database and physical changes including datafile addition and deletion

4.     Limited set of storage options

5.     Additional licenses are required if using 3^rd party, NetApp or EMC, snapshots capabilities 

2.    Provisioning Database Copies

Oracle Snap Clone can provision point-in-time clones of the Test Master from storage snapshots.

Challenges

1.     All target servers where clones are deployed must be licensed with

·       Oracle Database Lifecycle Management Pack

·       Cloud Management Pack

3.    Simplicity

Even customers who are familiar with Enterprise Manager may find that installing, configuring and managing DBaaS Snap Clone is non-trivial.

Delphix for Logical Recovery

1.    Synchronising with Source Database(s)

Delphix synchronises with source database seamlessly using an RMAN initial full backup and incremental forever backups including transaction log files.  All the ingested data is compressed to typically 50% of the size.  The compression saves storage for the source and virtual copies but more importantly improves the IO performance of virtual copies.

When we perform an incremental synchronisation (SnapSync) we can also validate the integrity of the database using validated synchronisation.  This will ensure that the backup copy we have can be used for recovery and the data is intact.  It also speeds up the process of provisioning a virtual copy.  The validated SnapSync could be run as frequently as required to support the recovery time objective.

Advantages

• With Delphix there is no requirement for a Standby Database
• Synchronisation is automatic regardless of any database changes (nologging, physical etc)
• Easy to define a retention policy for the span of time you want to keep backups
• Validated Sync can continuously check for corruptions and recoverability of the Delphix database copy
• No additional Oracle licenses required

2.    Provisioning Database Copies

Delphix can provision a virtual copy of a database in minutes to any point-in-time within the retention period of the source copy.  Provisioning can be performed via the GUI, CLI or API.  You can also provision as many copies as you want concurrently, from independent points in time to accelerate the time to restore service.

3.    Simplicity

                       

Delphix is easy to install, has automated discovery of source systems, once synchronisation is established with a retention period and one or more target servers are configured to provision virtual databases to there is very little monitoring or maintenance required.

Key advantages of Delphix over Oracle DBaaS Snap Clone 

1.     Easy to install and configure

2.     Complete automation of restore and recover process

3.     No requirement for multiple standby environments, avoiding setup, maintenance, monitoring, server capacity and licenses.

4.     Continuous validation and recovery of ingested backups as a further safeguard against corruptions and providing early detection of issues.

5.     Reduced Storage requirement

6.     Lower maintenance

7.     Minimal Licensing, with no additional licenses required if want to expand usage for provisioning non-production database copies

8.     More References

Why you should Deploy Delphix Now

Yadda, Yadda, Yadda

We are all tired of hearing about enterprise software which is

“Cost reducing, revenue expanding, investment returning, risk avoiding, cloud enabling, breath taking, productivity improving, agility accelerating, complexity taming, career enhancing, …”

We already have so much of that stuff we should be making money in spite of ourselves,  … wait a minute.

All customers have a finite budget, finite resources and an infinite to do list, which means that everyone has to prioritize.   For some customers, access to data without delay has made it onto the high priority, must do next, list.  For all other customers it seems like it would be beneficial but there are bigger fish to fry right now.

Brace yourselves, here comes the sales pitch

Delphix hits the ground running, from day one you will start releasing resources to then attack your highest priorities.    Delphix will automate tasks that currently consume valuable operational time allowing members of those teams to focus on what’s more important for your company right now.

Delphix is a fully automated data provisioning system and is packaged to be easily and quickly deployed.  Here are the steps.

1.    Import Delphix Virtual Machine into Hypervisor

2.    Allocate a network address to Delphix

3.    Allocate around 10-20% of the total non-production storage you would typically need (without Delphix)

4.    Register production or standby source servers with Delphix.

5.    Instruct Delphix to ingest selected databases, this starts a fully automated, policy driven, continuous synchronisation process

6.    Register non-production dev and test database servers with Delphix.

7.    Create and assign virtual database copies for your dev and test community in minutes

8.    Finished

All non-production database provisioning, versioning, refreshing, rewinding, achiving and general manipulation requests can now be delegated to Delphix.

Delphix without Delay

When trying to fix a complex problem, a key technique is to break down the problem into problems you can fix.  Deploying Delphix will fix your data access issues, but more importantly if your IT priorities lie elsewhere you can use Delphix to free up capacity to focus on those priorities.

Deploy Delphix Now

 

Agile Copy Data Management

Delphix Agile Copy Data Management

Copy Data Management

Whilst there has been a gradual evolution in agile infrastructure (IaaS) and software stack provisioning architectures (PaaS), Delphix provides the missing piece in the agile architecture jigsaw by addressing Data as a Service (DaaS) through agile Copy Data Management.

Copy Data Management is generally defined as a solution which takes care of the curation, provisioning and security of all non-production database copies for Development, Analytics, Operations and Data Protection.

Networked Storage

Storage was the first component targeted by outsourcers to consolidate.  Moving from siloed, dedicated, Direct Attached Storage (DAS) to networked storage allowed overall storage consumption to be reduced by consolidating unused capacity and also allowed storage to be managed centrally.  However one of the downsides was that networked storage, typically Storage Area Networks (SANs), required a dedicated fibre channel data network to ensure performance for the high volumes of data traffic moving between database servers and the networked storage arrays.

In today’s world of agile infrastructure where resources are pooled, and allocated using virtualization technologies, having a dedicated network is an anachronism.   A dedicated resource means that unused capacity cannot be used by other workloads and the dedicated resource itself cannot expand or burst out to use capacity from elsewhere.

A move from siloed networks requires high bandwidth networks where capacity can be appropriately partitioned and allocated to accommodate multiple workloads. The throughput and capacity of Ethernet networks are evolving extremely fast allowing a single team of network administrators to manage all network traffic.  High throughput Ethernet allows the network itself to be a pooled resource with all the flexibility, agility and cost advantages that brings.

Storage Snapshots

Storage Snapshots have been around for many years and were originally designed to enable consistent backups of active database systems.  A backup takes a long time and most database systems cannot be suspended for the entire duration of a backup.  Storage snapshots allow a database to be queisced for a brief duration whilst the snapshot is taken.  The database can then be un-queisced allowing transactions to proceed and a consistent backup of the database can then be taken asynchronously via the snapshot.

Clones of snapshots can be taken to provision database copies. However supporting clones has an impact on storage performance and hence clones are usually driven off a full copy of production maintained on a separate storage server.  This mitigates the performance impact of clones on the production storage array at the cost of maintaining a replication method and additional storage.

Unfortunately the performance of cloned storage snapshots also degrades quite rapidly over time with IOPS dropping by up to 50% and latency spikes of 20ms.

Like most technologies storage snapshots are great when used for what they were originally designed for but start to disintegrate for non-primary use cases.

Virtual Data

Virtualising a shared resource is a pre-requisite for IT agility, which is why Delphix virtualizes data.  Delphix virtual data allows many users to share the same copy of data with the appearance of having their very own private, dedicated, full sized, read-write copy.  Delphix compression and de-duplication allow Delphix to store a sequential timeline of multiple database versions spanning long retention periods.  Delphix compression also increases performance by reducing physical IO requests and expands the effective size of the Delphix data cache which further reduces the number of physical IO requests.  These are two of the primary reasons why Delphix virtual data is often faster than purely physical storage based solutions.

Designed for Agility

Delphix itself is deployed as a Virtual Machine to leverage the easier deployment, management, scalability and HA of a hypervisor environment.  Almost every customer has skills in managing Virtual Machine environments.

Delphix is storage agnostic and leverages the flexibility and high performance of Ethernet to provision access to shared database versions over the network using NFS and iSCSI. 

The final key ingredient for agility is automation.  Any manual process involved in common workflows becomes a constraint and renders a solution unpredictable and non-scalable.  Delphix automates the entire data capture, curation, provisioning and versioning processes.

Access to Delphix database version control is available out-of-the box through self-service automation providing GIT like capabilities for databases of any size.

We call this Agile Copy Data Management.