LoggerDaisy software platform designed with high availability in mind. High availability is a characteristic of a system, which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. Modernization has resulted in an increased reliance on these systems. For example, hospitals and data centers require high availability of their systems to perform routine daily activities. Availability refers to the ability of the user community to obtain a service or good, access the system, whether to submit new work, update or alter existing work, or collect the results of previous work. If a user cannot access the system, it is - from the users point of view - unavailable. Generally, the term downtime is used to refer to periods when a system is unavailable.WHAT IS A HIGH AVAILABILITY DATABASE?
High availability databases use an architecture that is designed to continue to function normally even when there are hardware or network failures within the system. They have emerged as an alternative to traditional relational databases, which are generally built to be deployed on a single server and rely on a master/replica architecture to provide availability. In the master/replica model, only the master is available for data updates unless it fails, at which time a replica is elected as a new master to take over. In theory, this model addresses the issue of availability, but in practice, there are still potential single points of failure. Architectural complexity can create issues in the transfer of the master role during failover and result in downtime.
High availability databases are built to eliminate single points of failure and are optimized to ensure that the end user does not experience an interruption in service or a degradation in user experience when hardware or networks fail. They are generally designed to make it easier and less complex to ensure high availability in a multiple node and cluster environment than is possible with a relational database. This is often accomplished through a masterless architecture that uses clustering, in which multiple servers are grouped together. Because there is no master, any server within a cluster can respond to read or write requests. Data is then replicated across all servers in the cluster, providing system redundancy and minimizing the possibility of downtime.