DISCONNECTED OPERATION WITHIN DISTRIBUTED DATABASE SYSTEMS

摘要

Techniques are disclosed for disconnected operation in a distributed database system. In an embodiment, the distributed database system implements a disconnected mode of operation allowing isolated regions of database nodes to provisionally commit transactions, with the global requirements of those transactions later satisfied by a transparent healing process after network connectivity is reestablished between the regions. The healing process, in turn, enables the distributed database system to construct a consistent global state of the database that accounts for the transactions provisionally-committed in each isolated region during the disconnected mode. Once the healing process completes, database clients “see” a healed version of the database that simulates or otherwise closely approximates a state of the database had the distributed database system performed the transactions during a normal, fully-connected, mode of operation.

主权项

1. A system for administering a distributed database including two or more predefined regions communicatively coupled via a communication network, each region including one or more database nodes, the database nodes collectively forming the distributed database, the system comprising:
at least one memory storing executable software instructions; and at least one processor configured to access the at least one memory and to execute the software instructions to:
determine network connectivity status between the two or more predefined regions of database nodes; andin response to determining the connectivity has been restored:
retrieve a transaction log from each predefined region of database nodes; andconstruct a new global state for the distributed database by at least:
traversing each transaction log and committing non-conflicting transactions to the new global state; andcausing conflicting transactions to be aborted such that a particular predefined region of database nodes that provisionally-committed a given conflicting transaction undoes database changes corresponding to the given conflicting transaction.