Database High Availability Services

Database High-Availability Services Overview
Database availability is the degree to which an application, service or function using a database is available on demand. Availability is measured by the perception of an application's end user. Business users, who want their systems to be ready to serve them at all times, need high availability.

Jaggy offers database high-availability design and implementation services for Oracle, MySQL, SQL Server, and DB2 databases.

Oracle Database Maximum Availability
Oracle High-Availability Oracle MAA (Maximum Availability Architecture) is Oracle's best practices blueprint based on proven high availability and recommendations. The goal of MAA is to achieve the optimal high availability architecture at the lowest cost and complexity. MAA best practices span across Oracle Database, Oracle Application Server, Oracle Applications and Grid Control.

  • Oracle RAC (Real Application Clusters) - If you are using Oracle databases, and you aren't already working with Oracle Real Application Cluster (RAC) databases, it's likely only a matter of time before you are. Oracle RAC databases can be used as a platform to provide scalability and high availability for Oracle databases, and this technology is being widely adopted as recent versions have demonstrated that Oracle delivers on these promises.
  • Oracle Data Guard - Oracle's Data Guard technology, formerly called Standby database in previous versions, provides a rolling copy of your production database. The standby database is started in read-only mode, constantly receiving change data, sent over from the production database, keeping it always in sync at all times, and at most only a few minutes behind. Were the production server to fail, that server could take over in less than the time the DNS change or IP swap would take. What's more the standby copy can be at another datacenter, or on another continent.
  • Oracle RAC and Data Guard - You can achieve the highest level of availability when using Oracle RAC and Oracle Data Guard and there is no need to make application changes to use these Oracle Database features. The combination of Oracle RAC and Oracle Data Guard provide the most comprehensive architecture for reducing downtime for scheduled outages and preventing, detecting, and recovering from unscheduled outages.
  • Oracle Golden Gate - Similar to using Oracle Data Guard in SQL Apply mode, Oracle GoldenGate can capture database changes, propagate them to destinations, and apply the changes at these destinations. Oracle GoldenGate is optimized for replicating data. Oracle GoldenGate can capture changes at a source database, and the captured changes can be propagated asynchronously to replica databases. A logical copy configured and maintained using Oracle GoldenGate is called a replica, not a logical standby database, because it provides many capabilities that are beyond the scope of the normal definition of a standby database.

Microsoft SQL Server High-Availability

  • SQL Server Failover Cluster - A SQL Server failover cluster is a single SQL Server instance installed across Windows Server Failover Clustering (WSFC) nodes. A SQL Server failover cluster leverages WSFC functionality to provide high availability through redundancy at the instance level—a Failover Cluster Instance (FCI). An FCI appears on the network as a single computer, but has functionality that provides failover from one node to another if the current node becomes unavailable.
  • AlwaysOn Availability Groups - AlwaysOn Availability Groups is an enterprise-level high-availability and disaster recovery solution introduced in Microsoft SQL Server 2012 to enable you to maximize availability for one or more user databases. AlwaysOn Availability Groups requires that the SQL Server instances reside on Windows Server Failover Clustering (WSFC) nodes.
  • Database Mirroring - Database mirroring is primarily a software solution to increase database availability by supporting almost instantaneous failover. Database mirroring can be used to maintain a single standby database, or mirror database, for a corresponding production database that is referred to as the principal database.
  • Log Shipping - Log shipping operates at the database level. You can use log shipping to maintain one or more warm standby databases (referred to as secondary databases) for a single production database that is referred to as the primary database.
  • Replication - Replication uses a publish-subscribe model. This lets a primary server, referred to as the Publisher, distribute data to one or more secondary servers, or Subscribers. Replication enables real-time availability and scalability across these servers. It supports filtering to provide a subset of data at Subscribers, and also allows for partitioned updates. Subscribers are online and available for reporting or other functions, without query recovery. SQL Server offers three types of replication: snapshot, transactional, and merge. Transactional replication provides the lowest latency and is usually used for high availability.

MySQL Server High-Availability

  • MySQL Cluster - MySQL Cluster enables organizations to deliver 5 Nines (99.999%) availability using a distributed, shared-nothing, multi-master architecture with no single point of failure that can be scaled out on commodity hardware. MySQL Cluster can be configured as in-memory and disk-based storage engine that synchronously replicates data to all data nodes in the cluster. This results in sub-second response time and extremely fast failover. Auto-sharding (partitioning), fail-over, and recovery are all automatically handled by MySQL Cluster, in addition to the ability to perform administrative functions online, including adding nodes, modifying schema, upgrades and back-ups, all without downtime.
  • MySQL with Windows Server Failover Clustering - With the certification and support of MySQL with Windows Server Failover Clustering (WSFC), organizations can safely deploy business-critical applications demanding high levels of availability, powered by MySQL Enterprise Edition and using native Windows Clustering services.
  • Oracle VM Template - Integrating MySQL Enterprise Edition with Oracle VM and Oracle Linux, the Oracle VM Template for MySQL is the fastest, easiest and most reliable way to provision virtualized and highly available MySQL databases. The Oracle VM Template for MySQL Enterprise Edition ensures rapid deployment and helps eliminate configuration efforts and risks by providing a pre-installed and pre-configured virtualized software image, taking advantage of Oracle VM's mechanisms to deliver high availability.

IBM DB2 High-Availability

  • IBM DB2 Clustering - To provide a high availability DB2® configuration, you can create a DB2 cluster across computers. In this configuration, the metadata repository database is shared between nodes in the cluster. If a failover occurs, another node in the cluster provides DB2 functionality.
  • IBM DB2 HADR - To provide high availability at the DB2® database level, you can create a DB2 high availability disaster recovery (HADR) configuration. In this configuration, a complete, separate copy of the database is maintained on a standby node at a local or remote location. The primary DB2 database processes transactions. It uses internal HADR processes to replicate transaction logs to the standby node, where the logs are stored. A process at the standby node then replays the logged transactions directly to the standby database. The two copies are maintained in synchronization or near-synchronization with each other.

Please contact us for pricing and additional information on Jaggy' Database High-Availability services.