Abstract: Techniques are described for providing service availability zones for computing-related services provided by a cloud provider network. According to some embodiments, the use of service availability zones enables users to achieve greater availability assurance for workloads sensitive to downtime or outages. The sensitivity of such workloads to downtime may be due to financial, regulatory, safety, or other reasons. Such availability-sensitive applications may in some cases be configured to run in multiple regions of a cloud provider network to increase their availability compared to running in a single availability zone. However, for some applications, the implementation of an application across multiple regions may not be feasible or desirable. The use of service availability zones provides user-visible fault domains within a single region of a cloud provider network, thereby enabling users to readily and reliably achieve application layer availability of approximately 99.

Abstract: Systems and methods are disclosed to implement a real-time data validation system that prevents problematic updates from being replicated from a primary database to a replica database. In embodiments, the data validation system injects a time delay into the replication process, so that when an update in a replication stream fails a specified data validation, the data validation system will prevent the update from being applied to the replica. In embodiments, the replication process is halted, a snapshot of the replica database is taken during the halt, and replication to the replica is resumed. Accordingly, if the problematic update is later confirmed to be invalid, the replica database can be rolled back to a point before the problematic update. Advantageously, the disclosed system can be used to implement a variety of data validations on top of a database replication process to protect the replica database from receiving undesired updates.

Abstract: Systems and methods are disclosed to implement a real-time data validation system that prevents problematic updates from being replicated from a primary database to a replica database. In embodiments, the data validation system injects a time delay into the replication process, so that when an update in a replication stream fails a specified data validation, the data validation system will prevent the update from being applied to the replica. In embodiments, the replication process is halted, a snapshot of the replica database is taken during the halt, and replication to the replica is resumed. Accordingly, if the problematic update is later confirmed to be invalid, the replica database can be rolled back to a point before the problematic update. Advantageously, the disclosed system can be used to implement a variety of data validations on top of a database replication process to protect the replica database from receiving undesired updates.