[This is a repost of my original blog on Oracle blog from about a year ago.]
Lets look at a relatively new feature in EM that has generated significant interest in a very short time – EM 12c DBaaS Snap Clone.
The ‘Oracle Cloud Management Pack for Oracle Database’ a.k.a
the Database as a Service (DBaaS) feature in EM 12c has grown tremendously
since its release two years ago. It started with basic single instance and RAC database provisioning, a technical service catalog, an out of box self service portal, metering and chargeback, etc. But since then we have added provisioning of schemas and pluggable databases, add/remove of Dataguard standby databases, full clones using RMAN backups, and Snap Clone. This video showcases the various EM12c DBaaS features.
This blog will cover one of the most exciting and popular features – Snap Clone. In one line, Snap Clone is a self service approach to creating rapid and space
efficient clones of large (~TB) databases.
Self Service – empowers the end users (developers, testers, data analysts, etc) to get access to database clones whenever they need it.
Rapid – implies the time it takes to clone the database. This is in minutes and not hours, days, or weeks.
Space Efficient – represents the significant reduction in storage (>90%) required for cloning databases
To best explain the benefits of Snap Clone, let’s look at a Banking customer scenario:
- 5 production databases total 30 TB of storage
- All 5 production databases have a standby
- Clones of the production database are required for data analysis and reporting
- 6 total clones across different teams every quarter
- For security reasons, sensitive data has to be masked prior to cloning
Based on the above scenario, the storage required, if using traditional cloning techniques, can be calculated as follows:
5 Prod DB = 30 TB
5 Standby DB = 30 TB
5 Masked DB = 30 TB (These will be used for creating clones)
6 Clones (6 * 30 TB) = 180 TB
Total = 270 TB
Time = days to weeks
As the numbers indicate, this is quite horrible. Not only 30 TB turn into 270 TB, creating 6 clones of all production databases would take forever. In addition to this, there are other issues with data cloning like:
- Lack of automation. Scripts are good but often not a long term solution.
- Traditional cloning techniques are slow while, existing storage vendor solutions are DBA unfriendly
- Data explosion often outpaces storage capacity and hurts ITs ability to provide clones for dev and testing
- Archaic processes that require multiple users to share a single clone, or only supports fixed refresh cycles
- Different priorities between DBAs and Storage admins
Snap Clone to the Rescue
All of the above issues lead to slow turnaround times, and users have to wait for days and weeks to get access to their databases. Basically, we end up with competing priorities and requirements, where the user demands self service access, rapid cloning, and the ability to revert data changes, while IT demands standardization, better control, reduction in storage and administrative overhead, better visibility into the database stack, etc.
EM 12c DBaaS Snap Clone tries to address all these issues. It provides:
- Rapid and space efficient cloning of databases by leveraging storage copy-on-write (or similar) technology
- Supports all database versions from 10g to 12c
- Supports various storage vendors and configurations NAS and SAN
- Lineage and association tracking between clone master and its various clones and snapshots
- ‘Time Travel’ capability to restore and access past data
- Deep visibility into storage, OS, and database layer for easy triage of performance and configuration issues
- Simplified access for end user via out-of-the-box self service portal
- RESTful APIs to integrate with custom portals and third party products
- Ability to meter and charge back on the clone databases
So how does Snap Clone work?
The secret sauce lies in the Storage Management Framework (SMF) plug-in. This plug-in sits between the storage system and the DBA, and provides the much needed layer of abstraction required to shield DBAs and users from the nuances of the different storage systems. At the storage level, Snap Clone makes use of storage copy-on-write (or similar) technology. There are two options in terms of using and interacting with storage:
1. Direct connection to storage: Here storage admins can register NetApp and ZFS storage appliance with EM, and then EM directly connects to the storage appliance and performs all required snapshot and clone operations. This approach requires you to license the relevant options on the storage appliance, but is the easiest and the most efficient and fault tolerant approach.
2. Connection to storage via Solaris file system (ZFS): This is a storage vendor agnostic solution and can be used by any customer. Here instead of connecting to storage, the storage admin mounts the volumes to a Solaris server and format it with ZFS file system. Now all snapshot and clone operations required on the storage are conducted via ZFS file system,. The good thing about this approach is that it does not require thin cloning options to be licensed on the storage since ZFS file system provides these capabilities.
For more details on how to setup and use Snap Clone, refer to a previous blog post.
Now, lets go back to our Banking customer scenario and see how Snap Clone helped then reduce their storage cost and time to clone.
5 Prod DB = 30 TB
5 Standby DB = 30 TB
5 Masked DB = 30 TB
6 Clones (6 * 30 TB) = 180 TB
6 Clones (6 * 5 * 2 GB) = 60 GB
270 TB 90 TB
days to weeks minutes
Assuming the clone databases will have minimal writes, we allocate about 2GB of write space per clone. For 5 production databases and 6 clones, this totals to just 60GB in required storage space. This is a whopping 99.97% savings in storage. Plus, these clones are created in matter of minutes and not the usual days or weeks. The product has out-of-the-box charts that show the storage savings across all storage devices and cloned databases. See the screenshot below.
Where can you use Snap Clone databases?
As i said earlier, Snap Clone is most effective when cloning large databases (~TBs). Common scenarios we see our customers best use Snap Clone are:
- Application upgrade testing. For example, EBusiness suite upgrade to R12.
- Functional testing. For example, testing using production datasets.
- Agile development. For example, run parallel development sprints by giving each sprint its own cloned database.
- Data Analysis and Reporting. For example, stock market analysis at the close of market everyday.
Its obvious that Snap Clone has a strong affinity to applications, since its application data that you want to clone and use. Hence it is important to add that the Snap Clone feature when combined with EM12c middleware-as-a-service (MWaaS) can provide a complete end-to-end self service application deployment experience. If you have existing portals or need to integrate Snap Clone with existing processes, then use our RESTful APIs for easy integration with third party systems.
In summary, Snap Clone is a new and exciting way of dealing with data cloning challenges. It shields DBAs from the nuances of different storage systems, while allowing end users to request and use clones in a rapid and self service fashion. All of this while saving storage costs. So try this feature out today, and your development and test teams will thank you forever.
Cloud Management Page on OTN
Cloud Administration Guide (Documentation)
Enterprise Manager 12c Database-as-a-Service Snap Clone Overview (Presentation)