high availability: All content tagged as high availability in NoSQL databases and polyglot persistence
The recent announcement of the Microsoft SQL Server 2012 release emphasized the high availability features added to this version. Here is what I could find after some digging through the documentation:
AlwaysOn Failover Cluster Instances: As part of the SQL Server AlwaysOn offering, AlwaysOn Failover Cluster Instances leverages Windows Server Failover Clustering (WSFC) functionality to provide local high availability through redundancy at the server-instance level—a failover cluster instance (FCI). An FCI is a single instance of SQL Server that is installed across Windows Server Failover Clustering (WSFC) nodes and, possibly, across multiple subnets. On the network, an FCI appears to be an instance of SQL Server running on a single computer, but the FCI provides failover from one WSFC node to another if the current node becomes unavailable.
This is explained in more detail on AlwaysOn Failover Cluster Instances (SQL Server).
AlwaysOn Availability Groups: The AlwaysOn Availability Groups feature is a high-availability and disaster-recovery solution that provides an enterprise-level alternative to database mirroring. Introduced in SQL Server 2012, AlwaysOn Availability Groups maximizes the availability of a set of user databases for an enterprise. An availability group supports a failover environment for a discrete set of user databases, known as availability databases, that fail over together. An availability group supports a set of read-write primary databases and one to four sets of corresponding secondary databases. Optionally, secondary databases can be made available for read-only access and/or some backup operations.
More documentation about AlwaysOn Availability groups can be found here.
Database mirroring: This feature will be removed in a future version of Microsoft SQL Server.
Log shipping: SQL Server Log shipping allows you to automatically send transaction log backups from a primary database on a primary server instance to one or more secondary databases on separate secondary server instances.
This is the well-known master-slave setup. More details can be found here.
Also worth checking the availability of these feature per SQL Server 2012 editions:
Original title and link: Microsoft SQL Server 2012 High Availability Solutions ( ©myNoSQL)
Xeround is a new MySQL storage engine offered as Database-as-a-Service.
What it promises sounds (a bit?) too good to be true (nb this list have been extracted from their site):
- seamless replacement of existing MySQL database
- high availability (including schema changes)
- automatic fault-detection and recovery
- full consistency with low latency
What’s the catch?
Original title and link: Xeround: MySQL Elastic, Always-on Storage Engine for the Cloud (NoSQL databases © myNoSQL)