Tuesday, July 21, 2015

Snap Cloning Databases on Exadata using Enterprise Manager

By Subhadeep Sengupta (Oracle)
Historically, Exadata has mostly been deployed for heavy, production workloads, leaving cheap commodity hardware and third-party storage to perform as infrastructure for Development and Testing. From the viewpoint of Enterprise Manager, we have seen customers clone production databases running on Exadata to secondary storage such as ZFS Storage Appliance or even third-party NAS or SAN for the purpose of testing. Customers mainly used RMAN (with or without Enterprise Manager) to clone the databases. While the master clones (often referred to as Test Master) could be further cloned via storage efficient snapshots, there were significant limitations to the approach.
  • First of all, the testing on non-like systems from Exadata (both compute and storage) often yielded erroneous inferences. 
  • Second, both the compute and storage on existing Exadata racks often remained underutilized.
Most surveys establish that there are several Dev/Test copies for every Production database, and leaving Dev/Test outside the realm of Exadata can only yield partial usage of engineered systems. 

Two recent advancements in Exadata break this existing barrier. First of all, the compute nodes on Exadata can now be virtualized. Consolidated environments can now use Oracle Virtual Machine (OVM) on X5-2, X4-2, X3-2, and X2-2 database servers to deliver higher levels of consolidation and isolation between workloads. The Virtual machines can be configured on demand with the appropriate number of Virtual CPUs (vCPUs) for iterative testing. Second, with Oracle Database 12c Release 1 (12.1) release BP5 or later, space-efficient database snapshots can now be quickly created for test and development purposes on Exadata.

Snapshots start with a shared read-only copy of the production database (referred to as the Test Master in Enterprise Manager Parlance) that has been masked and/or cleansed of any sensitive information. Snapshot technology as deployed on Exadata is "allocate on first write", not copy on write. As changes are made, each snapshot writes the changed blocks to a sparse disk group. Multiple users can create independent snapshots from the same base database, therefore multiple test and development environments can share space while maintaining independent databases for each task. The base database must remain read-only during the usable lifespan of snapshots that are created from that base database. If there is a need to create another set of snapshots from a more recent copy of production data, a new read-only base from a production database needs to be created.

Enterprise Manager 12cR5 leverages the capabilities of Exadata to extend the Snap Clone capabilities for Exadata Sparse clones. As shown in this tutorial, with Snap Clone, Enterprise Manager can create a Test Master using either Dataguard technology or RMAN preceded by data masking. The Test Master can be created either on the same Exadata rack or on a different one. Once the Test Master has been created, snapshots can then be created on the sparse disk groups using the Deployment Procedures. The Deployment Procedures also automate the post-cloning discovery and promotion of the cloned targets, making them fully managed right from inception. Internal testing confirms that for cloning a Terabyte of database with a complete discovery of all its components takes less than a minute.

Enterprise Manager also helps DBAs track the lineage of the clones by providing a report on the production database, the Test Master and its clones. Enterprise Manager Snap Clone on Exadata supports both regular as well as pluggable databases with optional ACFS configuration. In addition to support for Exadata sparse clones, Snap Clone continues to support NAS (ZFS Storage Appliance and NetApp) and SAN (certain EMC storage arrays), in case users want to deploy these for their Dev-Test environments. 
Further Reading Resources
  • To learn more about Database as a Service visit the otn page.
  • Prerequisites for setting up Exadata Snapshots are documented here.
  • Watch the video, Snap Clone Multitenant (Pluggable Database) on Exadata here.
--Subhadeep Sengupta (@Subh_here

Saturday, July 4, 2015

Managing Oracle Database 12c with Enterprise Manager – Part XVI

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we were exploring the Activity tab in the Performance Hub of Enterprise Manager Database Express 12c. Let us move to the Monitored SQL Tab.
This is the Real-time SQL Monitoring feature of the Diagnostics pack. This screen shows all the long running SQL statements (that have consumed 5 seconds or more of combined CPU and I/O time in a single execution, or are using parallel query).
Ever wondered why that report was taking so long? It is possible to drill down and see the plan steps executing for the SQL statement, as can be seen in the following screenshot. This helps considerably in analyzing long-running SQL statements.
The next two tabs of the Performance Hub show ADDM (Automatic Database Diagnostics Monitor) and its results, including Real-time ADDM which was previously used for emergency database issues, but now runs proactively to catch database issues before they cause a real problem.
For example, the following real-time ADDM report shows library cache contention, and the “Show Reasons” button suggests that the system is CPU bound.
Real-time ADDM runs in the database automatically every 3 seconds, and in this way is able to detect transient performance issues. The performance data in memory is examined, and any performance spikes are detected. The administrator is then informed of the spike and its root cause.
This blog post was originally published at this link.

Managing Oracle Database 12c with Enterprise Manager – Part XV

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we started to look into the Performance Hub of Enterprise Manager Database Express 12c. Let us move to the Activity tab.
The red line shows the CPU cores used by this VBOX image, and obviously at a point of time this line has been exceeded. The total CPU wait class can be seen in green, the red part shows the concurrency wait class and so on.
We can drill down to the actual SQL Id and user session at this point of time. However, we can also change the top dimensions of this graph to the actual wait event, as seen below.
Notice that the graph has now changed to display the individual wait events such as db file sequential read, log file parallel write, row cache lock and so on. You can drill down further on any of these wait events and find the actual SQL and session causing the events. 
You can also change the lower dimension, here we have drilled down on the wait event: db file sequential read, and changed the lower dimension to “object” – this displays the objects causing this wait event, and also the SQL below. Pretty powerful.
You can select a number of other dimensions such as SQL ID, object, Instance, PDB, Service, User ID, and so on in this graph.
This blog post was originally published at this link.

Thursday, May 21, 2015

Managing Oracle Database 12c with Enterprise Manager – Part XIV

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we discussed the new Enterprise Manager Database Express 12c, which is the replacement for the earlier Database Control (used in previous versions of the Oracle database such as 11g and 10g, to manage a single database).
One of the menu options in Database Express 12c is the Database Performance Hub. This gives a single view of DB performance - including ADDM, SQL Tuning, Real-Time SQL Monitoring, and ASH Analytics. It supports both a real-time & historical mode. There is a dedicated tab for RAC, if a RAC database is being used. It also has a historical view of SQL Monitoring reports.
Select Performance.. Performance Hub from the Database Express menu, the following page appears:
At the top, you can slide and select the time of interest. The information in the graphs below the slider changes accordingly. You can see the CPU load at the Host level, the total memory used by the database and its breakdown, the IO requests, and the Active sessions, foreground and background.
Before moving to the other tabs, click on the top PerfHub Report. This shows:
This is an Active Report that you are generating to hand over to your developers, so select the third option – All, which will save all the details including SQL statements.
The data is retrieved for the Active report, this takes a minute or so, and then the collection is completed.
Save the Active report as a file “perfhub_rt_10190900.html”. When you open up this file, the performance hub is seen as saved as a whole, including the various tabs.
Here we have moved to the Activity tab, which we will discuss in the next blog post.
This blog spot was originally published at this link.

Managing Oracle Database 12c with Enterprise Manager – Part XIII - Database Express 12c

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we briefly looked at the changes for Metering and Chargeback. We will now look at the new Database Express 12c.
Oracle Database 12c introduces “Enterprise Manager Database Express 12c” instead of Enterprise Manager Database Control that was available with previous versions of the database, such as 11g and 10g. The important thing to remember is that both Database control, and Database Express, can only be used to manage a single database as opposed to Enterprise Manager 12c Cloud Control.
As we can see, Enterprise Manager Database Express 12c provides basic administrator support for storage management(tablespaces, archive logs, control files, redo logs, undo tablespaces), security management (users, roles profiles),configuration management (initialization parameters, memory, database properties, feature usage), and performance diagnostics and tuning (Performance Hub and SQL Tuning Advisor).
For licensing purposes, the performance components require the Diagnostics and Tuning pack for Database 12c Enterprise Edition (EE). However the basic administration pieces can be used for free and also are accessible in Database 12c Standard Edition (SE).
Database Express 12c supports single instance or RAC databases, and Standard Edition (SE) or Enterprise Edition (EE). Since the administration activities supported are basic, the DBA will need to use a centralized Enterprise Manager Cloud Control installation for more advanced DBA activities on the database – such as setting up RMAN backups, Data Guard standbys, Database Resource Manager, Data Redaction and so on. These tasks obviously cannot be performed in Database Express 12c.
Database Express 12c can be installed along with the database (such as when the database is created using the Database Configuration Assistant (dbca)), in the same manner as Database Control 11g/10g. However, the difference between Database Control and Database Express, is that the latter runs inside the database and there are no extra Middleware components installed on the database server. The XDB server inside the database is used for web services. This itself is a welcome change.
Due to the improved and streamlined architecture, the disk space used is approximately only 20MB or so, and the CPU and memory overhead is also greatly reduced. 100% of the UI rendering for the screens is performed in the browser, and the database server only runs SQL - in contrast to the previous version of Database Control.
In the next blog post, we will take a closer look at the Database Performance Hub component of Database Express 12c.
This blog spot was originally published at this link.

Wednesday, April 22, 2015

Managing Oracle Database 12c with Enterprise Manager – Part XII

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we looked at how the Self-Service console would appear to the Self-Service Application (SSA) user, with the ability to provision databases, schemas or PDBs on the fly.
Metering and Chargeback is an important feature of the cloud. Due to the agile self-service nature of the cloud, it is important to set up quotas for the consumers, as well as meter the usage of the cloud, and use calculated dollar costs for showback or chargeback, so that the cloud is not exploited by over-usage by the consumers. This would also serve as a way for an internal IT department to show its value to the other business units, by putting an internal cost to its services – at least for showback purposes.
The “Chargeback and Capacity Planning Plug-in” (from EM12c Release 3) started to provide support for Oracle Pluggable Databases (12c PDBs). This enabled the Chargeback administrator to add a Container Database (CDB) to Chargeback, and assign each Pluggable Database (PDB) individually to a cost center.
This plug-in is now renamed to the latest available “Oracle Consolidation Planning and Chargeback” as can be seen via Setup.. Extensibility.. Plug-ins from the Enterprise Manager console.
A friend recently asked me: “Can I use showback / chargeback for an already existent database, that is, without the need to create a database as a service?”
My answer was that you cannot use chargeback unless you fully license the DBLM pack and Cloud Management pack and add the database as a resource to a zone with a charge plan. You don’t need to set up the full Database-as-a-service and enable self-service, it will just calculate the usage for an existing database if it is added in this way.
For more information on setting up chargeback, refer to the documentation here.
This blog post was originally published at this link.

Managing Oracle Database 12c with Enterprise Manager – Part XI

We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we looked at “Database as a Service” and “Schema-as-a-Service”, and also talked about “Pluggable database (PDB) as a Service (PDBaaS)”.
The “Schema as a Service” capability was introduced since the Cloud plug-in “Enterprise Manager for Oracle Cloud (SSA)”. The renamed plug-in “Oracle Cloud Application” was later released in October 2013. This added the capability of the Pluggable Database as a Service, i.e. PDBaaS.
Note that the current plug-in version available is Oracle Cloud Application To check your version, go to Setup.. Extensibility.. Plug-ins from the Enterprise Manager console.  
If your plug-in version is not equivalent to the above, you may need to update your plug-in using Setup.. Extensibility.. Self Update. For more information on the self update process, please see the documentation here. You will need to be on Enteprrise Manager 12c Release 4 ( in order to use the latest plug-in. If you are on an earlier release of Enterprise Manager, you will not be able to update the plug-in to the latest version.
The final aim of the Cloud Administrator, on setting up the database pools, service catalog, quotas and chargeback plans, is to provide the self-service capability to the SSA (Self-Service Application) user as can be seen below – the ability to ask for and get databases, schemas and PDBs via self-service.

More in the next blog post. 
This blog post was originally published at this link.


Opinions expressed in this blog are entirely the opinions of the writers of this blog, and do not reflect the position of Oracle corporation. No responsiblity will be taken for any resulting effects if any of the instructions or notes in the blog are followed. It is at the reader's own risk and liability.

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