Comprehensive and Detailed In-Depth Explanation:
High Availability (HA) in Appian Cloud is designed to ensure that applications remain operational and data integrity is maintained even in the face of hardware failures, network issues, or other disruptions. Appian’s Cloud Architecture and HA documentation outline the benefits, focusing on redundancy, minimal downtime, and data protection. The question asks for two advantages, and the options must align with these core principles.
Option B (Data and transactions are continuously replicated across the active nodes to achieve redundancy and avoid single points of failure):This is a key advantage of HA. Appian Cloud HA instances use multiple active nodes to replicate data and transactions in real-time across the cluster. This redundancy ensures that if one node fails, others can take over without data loss, eliminating single points of failure. This is a fundamental feature of Appian’s HA setup, leveraging distributed architecture to enhance reliability, as detailed in the Appian Cloud High Availability Guide.
Option D (In the event of a system failure, your Appian instance will be restored and available to your users in less than 15 minutes, having lost no more than the last 1 minute worth of data):This is another significant advantage. Appian Cloud HA is engineered to provide rapid recovery and minimal data loss. The Service Level Agreement (SLA) and HA documentation specify that in the case of a failure, the system failover is designed to complete within a short timeframe (typically under 15 minutes), with data loss limited to the last minute due to synchronous replication. This ensures business continuity and meets stringent uptime and data integrity requirements.
Option A (An Appian Cloud HA instance is composed of multiple active nodes running in different availability zones in different regions):This is a description of the HA architecture rather than an advantage. While running nodes across different availability zones and regions enhances fault tolerance, the benefit is the resulting redundancy and availability, which are captured in Options B and D. This option is more about implementation than a direct user or operational advantage.
Option C (A typical Appian Cloud HA instance is composed of two active nodes):This is a factual statement about the architecture but not an advantage. The number of nodes (typically two or more, depending on configuration) is a design detail, not a benefit. The advantage lies in what this setup enables (e.g., redundancy and quick recovery), as covered by B and D.
The two advantages—continuous replication for redundancy (B) and fast recovery with minimal data loss (D)—reflect the primary value propositions of Appian Cloud HA, ensuring both operational resilience and data integrity for users.
[References: Appian Documentation - Appian Cloud High Availability Guide, Appian Cloud Service Level Agreement (SLA), Appian Lead Developer Training - Cloud Architecture., , The two advantages of having High Availability (HA) for Appian Cloud applications are:, B. Data and transactions are continuously replicated across the active nodes to achieve redundancy and avoid single points of failure. This is an advantage of having HA, as it ensures that there is always a backup copy of data and transactions in case one of the nodes fails or becomes unavailable. This also improves data integrity and consistency across the nodes, as any changes made to one node are automatically propagated to the other node., D. In the event of a system failure, your Appian instance will be restored and available to your users in less than 15 minutes, having lost no more than the last 1 minute worth of data. This is an advantage of having HA, as it guarantees a high level of service availability and reliability for your Appian instance. If one of the nodes fails or becomes unavailable, the other node will take over and continue to serve requests without any noticeable downtime or data loss for your users., The other options are incorrect for the following reasons:, A. An Appian Cloud HA instance is composed of multiple active nodes running in different availability zones in different regions. This is not an advantage of having HA, but rather a description of how HA works in Appian Cloud. An Appian Cloud HA instance consists of two active nodes running in different availability zones within the same region, not different regions., C. A typical Appian Cloud HA instance is composed of two active nodes. This is not an advantage of having HA, but rather a description of how HA works in Appian Cloud. A typical Appian Cloud HA instance consists of two active nodes running in different availability zones within the same region, but this does not necessarily provide any benefit over having one active node. Verified References: Appian Documentation, section “High Availability”., , , ]
