Titan SiliconServer for 9i Abstract Challenges facing deployment include the ever-growing size of the database and performance scalability. Enterprise businesses rely heavily on databases for day-to-day business transactions and for business decision systems. In today s information age, databases form the core of enterprise business processing & information systems, with the load on databases and their size growing exponentially. This requires an everexpanding quantity of storage and fast access to data, and necessitates demanding backup schedules and disaster recovery procedures. This technology brief addresses technical issues and considerations for deploying 9i database on BlueArc s Titan SiliconServer. Author: Vicky Chau, Senior Architect
Challenges In today s competitive marketplace, the manageability and availability of a company s database is crucial. For many companies, their database is their lifeblood and therefore, a robust infrastructure built to support this application is a requirement. New advances in server and storage technologies provide customers with new opportunities to accelerate business and ensure reliability and anytime access to data. Traditionally, databases have been hosted on locally attached storage, putting severe constraints on the growth of the server and precluding use of the storage pool by other servers and applications. Growth of the database then stresses the local disk subsystems, resulting in the need for frequent upgrades and migration of the application servers. As the database grows, it becomes dramatically more difficult to reliably backup multiple servers each day, further challenging performance and the recoverability in case of a disaster. In the event of corruption of the database, business requirements demand database restoration with minimal down time. Yet by utilizing tape as the backup media, this restoration process can be hours or even days - hardly minimal downtime. An alternative solution must be found. BlueArc s Titan SiliconServer The high speed, high availability, and recoverability of BlueArc s Titan SiliconServer make it the ideal candidate for hosting databases. The Titan s built-in snapshot feature is designed with enterprise database deployment in mind and makes the backup and restoration of an databases simple and painless. While the SiliconServer Architecture provides unmatched serving speeds for backend database files, the system s 256 terabyte capacity satisfies growth needs for even the most demanding enterprise database development and production environments easily accommodating future growth. Titan SiliconServer 9i Production Development Archive Logs Snap Snap Snap and Snapshot Data Protection Page 1
Protocol Support Titan supports standard industry protocols such as NFSv2, NFSv3, CIFS, FTP, iscsi, and NDMP, enabling seamless integration in true heterogeneous environments. The consolidation of storage results in lower total cost of ownership (TCO), and provides convenient centralized backup and restoration. Offloading Disk I/O from Servers The high throughput and capacity of Titan allows for the consolidation of multiple server databases onto a single system, thus increasing availability and productivity. By offloading database I/O to the Titan, the existing application servers can now handle a greater user load without requiring upgrades, thus providing a lower TCO. Fast Disk for Multiple s and Application Servers For environments such as development, staging and QA, many databases could be needed, each requiring multiple instances. Titan s SiliconServer Architecture ensures that each instance and server receives the highest attainable level of performance. Additionally, Titan is a network attached storage (NAS) device, so there is no need to add high-speed local disk to each server, or expensive HBA s, as one would when deploying a storage area network (SAN). This allows users to deploy servers on demand, because no high-speed local disk is required. Not only can IT and development deploy many servers more quickly, but this strategy also ensures that in the event of a server s hardware failure, the same database can be mounted using a second, identical server providing cold standby capability, without tying data to local hardware. Instant Painless Backup The Titan s snapshot capabilities shorten the backup window for the database backup from a matter of hours or days down to a few seconds, virtually eliminating the need for a backup window. Restoration from snapshots is equally rapid, reducing this time to a few minutes, instead of several hours or days needed when restoring from tape. Depending on the organization s requirements, the DBA can opt for either cold or hot backup of the database files. Hot Backups Hot backups allow the database to stay open during the backup, ensuring uninterrupted access to data by applications & users and 24x7 availability. At the same time, hot backups provide uncompromising 100% point-in-time recovery, should the need arise to restore the database in case of an incident. Also, as the database instance is not shut down, memory used by the instance is not reset, allowing database to maintain performance levels through continued use of cache, without incurring any additional I/O to the disk. Hot Backup Mode Snapshot Normal Mode To enable hot backups, the database must be in ARCHIVELOG mode. Once in ARCHIVELOG mode, all transactions taking place on the database are logged and online redo logs are archived. Each database has multiple redo log files which are written sequentially by in a cyclic fashion. will write to the first redo log file, and when it is filled, it will start Page 2
writing to the second redo log file. In the meantime, it will make a copy of the first redo log file and archive it at the specified destination for safekeeping, should it be required for database recovery. Taking the snapshot backup of the database is a three-step process. Here is a simple example script you will need to accomplish a hot backup. STEP1: Put the tablespaces in the Hot-backup mode: ALTER TABLESPACE USER BEGIN BACKUP; ALTER TABLESPACE SALES BEGIN BACKUP; ALTER TABLESPACE MARKETING BEGIN BACKUP; ALTER TABLESPACE ENGINEERING BEGIN BACKUP; STEP2: Take a snapshot of the database hosted on the Titan: sictrl.exe -u username -p password 192.168.10.5 /fs/snapshot mk -r SnapshotQue STEP3: Put the tablespaces in normal mode: ALTER TABLESPACE USER END BACKUP; ALTER TABLESPACE SALES END BACKUP; ALTER TABLESPACE MARKETING END BACKUP; ALTER TABLESPACE ENGINEERING END BACKUP; ALTER SYSTEM DATABASE ARCHIVE LOG CURRENT; ALTER DATABASE BACKUP CONTROLFILE TO O:\ORA\CTRLBKUP.CTL ; ALTER DATABASE BACKUP CONTROLFILE TO TRACE; At this point, a checkpoint is forced to switch and archive the current redo log file to Archivelog. The final two commands in step 3 require a copy of the control file to another location in the file system and backing it up to the trace. Some DBAs prefer to use ALTER SYSTEM SUSPEND, after putting the tablespace in backup mode and before a snapshot is taken. This suspends all I/O activity to the control files, datafiles, and file headers, effectively temporarily freezing the database. This allows the snapshot backup on still data, without any transactions in progress and without shutting down the database. The ALTER DATABASE RESUME command takes the database out of suspend mode for normal operations. The BEGIN BACKUP command does not affect the accessibility of the tablespace by users and applications. While the backup is in progress, you cannot take the table space offline or shut down the instance. A typical backup of a tablespace may take several hours, depending on the size of the tablespace and the throughput of the backup device. Snapshots on Titan only take a few seconds to complete, returning control back to you almost immediately for other administrative tasks. Should an instance failure occur, or if the "SHUTDOWN ABORT" command is given after you have issued the BEGIN BACKUP command on a table space, the database presumes that the media recovery is required on this table space at the next instance startup. Media recovery may possibly require access to the archived redo logs to recover the tablespace. Backup using the snapshot feature of Titan takes only a few seconds, shrinking this time window to near-elimination. While the tablespace is in read-only mode, commands such as BEGIN BACKUP and END BACKUP will not work. Additionally, these two commands cannot be used with temporary locallymanaged tablespace. Page 3
Cold Backups Cold backups require that the database be shut down in a consistent state while database files are sent to the backup media. During the cold backup period, the database is not available to its users and applications. Cold backups of the database can be scheduled during the maintenance window. Typically, cold backups can take up to several hours depending upon the speed of the backup device. Businesses, which do not have maintenance window of several hours every day, can take advantage of snapshots to complete the cold backup in a few seconds and bring back the database online without compromising their productivity and backup policy. Once the snapshot is taken, database files can be backed up to the backup device from the snapshot without effecting the database operations. Ready to Serve Replication Shutdown Snapshot Startup In multiple instance environments, an active/active Titan cluster can be deployed to provide a highly available Ready-to-use database architecture without adding complexity to configuration or incurring any additional license fees. The Ready-to-use replicated database architecture is transparent to and works with any existing implementation. Titan Active-Active Cluster 9i Server One Snapshot of Two Two Snapshot of One 9i Server Ready to serve Replicated Architecture As shown in the figure above, two BlueArc Titans are deployed, each with its independent storage. Two separate instances host their production databases on Titan one and Titan two respectively. Snapshots are created, using one of the preferred backup methods (either hot or cold). After the creation of the snapshots, the snapshoted database files of the first instance are copied from the snapshot directory on the first Titan to a volume on the second. Similarly, the Page 4
snapshoted database files from the second instance are copied from the second Titan to a volume on the first. In the event of database corruption, or accidental deletion of data, the database instance can be reconfigured to start and point to the second set of database files available from the second Titan. Up to the minute archived redo logs will need to be applied to this copy of the database to bring it to the desired transaction level before brining it online - ensuring nearly zero downtime without investing in an expensive, complex synchronous software/hardware solution and the associated administrative costs. Titan SiliconServer 9i Production Server Developers Workstations 9i Development Server Production Copy of Production Instances and Hosting Multiple s Sharing an with Another Instance In enterprise environments, a copy of the database may be required for development and other purposes. Usually this is a lengthy process, requiring the creation of a complete backup of the database and restoration from this backup to the development database server. Using Titan, this can easily be accomplished in a very short time. First, a snapshot is taken of the production database on Titan, and using BlueArc s Accelerated Data Copy (ADC) the database is copied from a production volume snapshot to the development volume in a very short time. Once the database is copied to the development volume, development servers can point to this copy of the database. Page 5
Conclusion Challenges facing deployment include the ever-growing size of the database and performance scalability. In today s information age, databases form the core of enterprise business processing & information systems, with the load on databases and their size growing exponentially. Titan SiliconServer with 9i offers the most scalable network storage available for customers, allowing them to easily deploy data-intensive enterprise applications critical to business success. Titan speeds database operation by offloading file system workload and data backup operations into advanced Silicon-based technology, allowing a single system to manage more database services, avoiding the cost and administration problems of server proliferation reducing management complexity and total cost of ownership. Contact BlueArc today at 1-866-864-1040 to learn more, or visit www.bluearc.com BlueArc Contact Information BlueArc Corporation BlueArc UK Ltd. Corporate Headquarters Queensgate House 225 Baypointe Parkway Cookham Road San Jose, CA 95134 Bracknell RG12 1RB USA United Kingdom info@bluearc.com uk_info@bluearc.com T 408 576 6600 T +44 (0) 1344 408 200 F 408 576 6601 F +44 (0) 1344 408 202 Or visit our Web site at: http://www.bluearc.com Page 6