In terms of dealing with performance, scalability and also reliability issues within web systems and its software infrastructure it is necessary to observe several topics. This includes everything ranging from web protocols as well as content distribution systems to the architecture of large-scale systems used for web data serving, analysis, and cloud computing and storage as well. Since some of these characteristics like performance, scalability, and HA (high availability) are often used interchangeably, it is possible to have some confusion about them. That can result in unrealistic metrics as well as in deployment delays. For that reason, it is significant to invest some time and find the differences between these approaches.
Performance represents a system that is throughput under a given workload in a particular timeframe. It is validated through the process of testing both the scalability and the reliability of hardware, software, and network as well. This is a continuous process and not a final result. Performance requirements experience massive changes since features and functionalities are always added and eliminated in order to accommodate evolving business requirements.
Scalability refers to the ability of a system or an application to handle a massive volume of workload, or on the other hand expand in response to the increased demand for access to the database, as well as its processing, networking, or system resources.
High availability is the characteristic which allows your apps remain available and accessible without any possible interruptions. HA is accomplished in case your database cluster continues to operate even during some unpredictable complications like in case one or more servers are blown up, shut down, or simply disengaged from the rest of the network. Many factors can affect the high availability, and in order to prevent any issues with applications and system it is necessary to ensure that:
- The same components need to be deployed to every command within the cluster
- Your failover mechanism must concern the availability of nodes in a particular cluster together with their exact location
- The failover mechanism must track the progress of all current tasks in order to ensure a roll back at the time when a given operation has failed
If one of the servers in a cluster unexpectedly fails, database load balancing software with the help of a failover mechanism has the opportunity to ensure seamless rerouting of requests while preventing troubles to the other users who try to access the rest of the cluster.