Abstract: In one embodiment, two-phase mutation of an ordered tree data structure is performed, wherein a lock can be acquired on a first node in an ordered tree data structure, and an identifier for the first node can be added to a lock path data structure. A second node can also be locked, and an identifier for the second node can be added to the lock path data structure. Subsequently, a set of operations to perform on the ordered tree responsive to a modification of the second node can be determined for each node affected by the modification, and the operation for each node can be stored in the lock path data structure. Once the operations for the nodes have been determined, the operations listed in the lock path can be performed.

Abstract: In one embodiment, two-phase mutation of an ordered tree data structure is performed, wherein a lock can be acquired on a first node in an ordered tree data structure, and an identifier for the first node can be added to a lock path data structure. A second node can also be locked, and an identifier for the second node can be added to the lock path data structure. Subsequently, a set of operations to perform on the ordered tree responsive to a modification of the second node can be determined for each node affected by the modification, and the operation for each node can be stored in the lock path data structure. Once the operations for the nodes have been determined, the operations listed in the lock path can be performed.

Abstract: A method for maintaining an index in multi-tier data structure includes providing a plurality of a storage devices forming the multi-tier data structure, caching an index of key-value pairs across the multi-tier data structure, wherein each of the key-value pairs includes a key, and one of a data value and a data pointer, the key-value pairs stored in the multi-tier data structure, providing a journal for interfacing with the multi-tier data structure, providing a plurality of zone allocators recording which zones of the multi-tier data structure are in used, and providing a plurality of zone managers for controlling access to cache lines of the multi-tier data structure through the journal and zone allocators, wherein each zone manager maintains a header object pointing to data to be stored in an allocated zone.