Bilal Mehdi, senior consultant at GlassHouse Technologies (UK) discusses the benefits of new database virtualisation and active/active databases.
Today’s datacenter environments, typical enterprise applications are heavily reliant on the availability of data. Standard architectures of enterprise applications can have a single point of failure and a performance bottleneck at the database tier.
The database typically consists of a large SMP system that has been architected for peak load and can only be scaled vertically by adding additional resources to the SMP system (e.g. adding additional CPUs or memory).
Availability considerations for the database typically consist of an identical – and normally idle – backup database system with data synchronisation between the systems.
Recently the market has seen a new raft of products and solutions become available, which provide both uni-directional and bi-directional replication between the database management systems and platforms.
These solutions provide low-latency, scalability, selectivity, and enhanced data transformation as well as mapping when required.
These data replication and database virtualisation technologies provide the highest level of disaster tolerance available. This enables two or more simultaneously active systems at geographically dispersed locations, each with its own copy of the database, within the architecture.
This means that applications and databases are scalable across multiple physical nodes to create one logical system that can scale linearly and survive the failure of an entire node.
These active/active database and data replication technologies for database environments support various architectures that can avoid data collisions, as well as provide for data collision identification and resolution using various algorithms.
These solutions provides continuous processing solutions for Oracle, MySQL, DB2, SQL Server, Sybase, and HP NonStop databases on UNIX, Linux, Windows, and NonStop platforms.
The following benefits can be achieved from the database virtualisation solutions available in the market:
• Continuous Availability
In a horizontal grid of servers, one or more systems may fail without affecting the availability of the service. For the data tier, this enables continuous data access during planned and unplanned outages. Administrators can perform rolling upgrades and other maintenance tasks, which previously required planned outages while the application remained available
• On-Demand Scalability
Additional servers can be easily added or removed on-demand to ensure sufficient processing power for SLAs without the overhead of having low resource utilisation rates.
• Lower Costs
Lower cost commodity servers are well suited for horizontally scaled architectures. This provides a significantly lower capital and operating cost compared to SMP systems.
• Business Agility
Centrally managed pool of active/active databases provide enterprises with enhanced ability to change applications more quickly to meet business requirements, to change deployment characteristics and to provision new databases based on application need.