Abstract: A method and apparatus are described for assigning mastership of nodes to data blocks. A method involves connecting each session of a plurality of sessions to a particular node of a cluster of nodes based on services associated with the plurality of sessions. Each session of the plurality of sessions is associated with a respective service of a plurality of services. The method also involves collecting service-based access statistics aggregated by service and ranges of data block addresses. Each range corresponds to one or more contiguous subrange of data block addresses. The method further involves assigning mastership of the nodes to the data blocks having addresses within said ranges of data block addresses based on services associated with the nodes and the service-based access statistics.

Abstract: Techniques related to cache recovery for failed database instances are disclosed. A first database instance and a second database instance share a primary persistent storage and a secondary persistent storage. Each database instance stores, in volatile memory, a respective primary cache of a respective set of data stored on the primary persistent storage. Each database instance also stores, in volatile memory, a respective set of header data. Further, each database instance moves the respective set of data from the respective primary cache to a respective secondary cache on the secondary persistent storage. Still further, each database instance stores, on the secondary persistent storage, a respective set of persistent metadata. When the first database instance becomes inoperative, the second database instance retrieves, from the secondary persistent storage, persistent metadata corresponding to data stored in a secondary cache of the first database instance.

Abstract: A method, system, and computer program for high-availability database systems. The method commences by replicating (e.g., from a first server to a second server) a data structure having entries describing resource locks and client states. The replication can be performed to any number of servers. Upon detecting a failure of a connection between the first server and a client to which the first server is connected, the system establishes a new connection between the second server and the client by updating the replicated data structure to describe new connection between the second server and the client and updating the entries of the replicated data structure to reflect the new connection and the then current aspects of the resource locks and client states. The client can be a database instance, and the act of replicating can be accomplished using a broadcast channel. The servers can be organized in a computing cluster.

Abstract: Techniques related to cache recovery for failed database instances are disclosed. A first database instance and a second database instance share a primary persistent storage and a secondary persistent storage. Each database instance stores, in volatile memory, a respective primary cache of a respective set of data stored on the primary persistent storage. Each database instance also stores, in volatile memory, a respective set of header data. Further, each database instance moves the respective set of data from the respective primary cache to a respective secondary cache on the secondary persistent storage. Still further, each database instance stores, on the secondary persistent storage, a respective set of persistent metadata. When the first database instance becomes inoperative, the second database instance retrieves, from the secondary persistent storage, persistent metadata corresponding to data stored in a secondary cache of the first database instance.

Abstract: A method and apparatus are described for assigning mastership of nodes to data blocks. A method involves connecting each session of a plurality of sessions to a particular node of a cluster of nodes based on services associated with the plurality of sessions. Each session of the plurality of sessions is associated with a respective service of a plurality of services. The method also involves collecting service-based access statistics aggregated by service and ranges of data block addresses. Each range corresponds to one or more contiguous subrange of data block addresses. The method further involves assigning mastership of the nodes to the data blocks having addresses within said ranges of data block addresses based on services associated with the nodes and the service-based access statistics.

Abstract: A method, system, and computer program for high-availability database systems. The method commences by replicating (e.g., from a first server to a second server) a data structure having entries describing resource locks and client states. The replication can be performed to any number of servers. Upon detecting a failure of a connection between the first server and a client to which the first server is connected, the system establishes a new connection between the second server and the client by updating the replicated data structure to describe new connection between the second server and the client and updating the entries of the replicated data structure to reflect the new connection and the then current aspects of the resource locks and client states. The client can be a database instance, and the act of replicating can be accomplished using a broadcast channel. The servers can be organized in a computing cluster.