Dell Products Inc.

Emc IP Holding Company LLC

Jason E Raff

Vikram A Prabhakar

Socheavy D Heng

Shari Vietry

David Bernard

Vladimir Shveidel

Vamsi K Vankamamidi

Bar David

Mayank Ajmera

Ben Beauregard

A technique is directed to sharing a page of memory among a first processing node and a second processing node. The technique includes provisioning the first processing node with a first queue and the second processing node with a second queue. The technique further includes configuring the first processing node to enqueue, within the first queue, local lock requests to assign lock ownership of the page to the first processing node and peer lock requests to assign lock ownership of the page to the second processing node. The technique further includes configuring the second processing node to enqueue, within the second queue, the peer lock requests to provide lock ownership coordination of the page among the first processing node and the second processing node.

Locking in multi-node environments

A technique is directed to servicing a read request. The technique includes establishing a set of write indicators corresponding to a set of storage locations designated by the read request. The technique further includes, while the set of write indicators is accessible to a possible write operation that designates the set of storage locations to be written to, buffering data from the set of storage locations. The technique further includes, after buffering the data from the set of storage locations, checking the set of write indicators to ascertain whether the set of storage locations has been designated to be written to since establishing the set of write indicators.

Servicing read requests

A method, computer program product, and computing system for receiving a metadata input/output (IO) request on a first storage node of a storage system. The metadata IO request may be partitioned into a plurality of metadata pages. The plurality of metadata pages may include a plurality of logical metadata pages and a plurality of virtual metadata pages. A family identifier may be obtained for each logical metadata page. The family identifier is a unique identifier assigned to a group of related metadata elements that share data, and is stored in a family identifier locking table. At least one of the plurality of metadata pages may be locked from access by a second storage node using the family identifier. The metadata IO request may be processed on the plurality of metadata pages by loading the at least one of the plurality of metadata pages into a memory of the first storage node.

System and method for managing metadata access locking in cache

Improved techniques are directed to managing a cache in an electronic environment in which a first processing core is configured to utilize a first set of queues to reclaim the pages of the cache and a second processing core is configured to utilize a second set of queues to reclaim the pages of the cache. The techniques include adding, to a queue in the first set of queues, an entry identifying access information of a page of the cache. The techniques further include accessing the page by a second processing core. The techniques further include, while the entry is in the first set of queues, updating the access information by the second processing core to indicate accessing the page by the second processing core.

Managing caches using access information of cache pages

A technique of managing locks in a transaction cache includes opening, in the transactional cache, a first transaction identifying a first plurality of pages to be accessed and a second transaction identifying a second plurality of pages to be accessed, where the first plurality of pages has at least one page in common with the second plurality of pages. The technique further includes selecting a target page that is highest in a predefined page ordering out of the at least one page in common. The second plurality of pages includes a lower-ordered page that is lower in the predefined page ordering than the target page. The technique further includes, while the first transaction is open, inserting a first lock request of the second transaction into a queue of the target page and preventing insertion of a second lock request of the second transaction into a queue of the lower-ordered page.

Managing locks in a transactional cache

A method, computer program product, and computer system for acquiring, by a first node, local locks of the first node associated with a metadata log transaction, wherein the first node acquires the local locks of the first node prior to sending a commit message to a second node. The second node may acquire local locks of the second node associated with the metadata log transaction, wherein the second node acquires the local locks of the second node based upon, at least in part, receiving the commit message from the first node.

System and method for consistent metadata access based on local locks semantics in a multi-node cluster

Techniques for in-band locking of extents containing multiple pages of shared non-volatile data storage are disclosed in which inter-node lock request messages indicate both an individual page for which a lock is requested and the multi-page extent that contains that page. A page lock or an extent lock is granted to the requesting node based on the time since the last access to the extent by the node to which the request was sent. A generation number may be maintained in each node and stored in the per-extent lock table entries and per-page lock table entries such that pages accessed by a node within an extent while the extent is in extent-locked access mode may subsequently be accessed by the node during a page-locked access mode for the extent occurring after the extent-locked access mode ends based on page locks created by the node during the extent-locked access mode.

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Bedford, NH, United States of America

Jason E Raff