Hitachi Data Systems Corporation

Archivas, Inc.

Hitachi Vantara Corporation

Benjamin K D Bernhard

David M Shaw

Andres Rodriguez

Jack A Orenstein

Robert S Mason, Jr

An archive cluster application runs across a redundant array of independent nodes. Each node runs an archive cluster application instance comprising a set of software processes: a request manager, a storage manager, a metadata manager, and a policy manager. The request manager manages requests for data, the storage manager manages data read/write functions, and the metadata manager facilitates metadata transactions and recovery. The policy manager implements policies, which are operations that determine the behavior of an 'archive object' within the cluster. The archive cluster application provides object-based storage. It associates metadata and policies with the raw archived data, which together comprise an archive object. Object policies govern the object's behavior in the archive. The archive manages itself independently of client applications, acting automatically to ensure that object policies are valid.

Policy-based management of a redundant array of independent nodes

An archive cluster application runs in a distributed manner across a redundant array of independent nodes. Each node preferably runs a complete archive cluster application instance. A given nodes provides a data repository, which stores up to a large amount (e.g., a terabyte) of data, while also acting as a portal that enables access to archive files. Each symmetric node has a set of software processes, e.g., a request manager, a storage manager, a metadata manager, and a policy manager. The request manager manages requests to the node for data (i.e., file data), the storage manager manages data read/write functions from a disk associated with the node, and the metadata manager facilitates metadata transactions and recovery across the distributed database. The policy manager implements one or more policies, which are operations that determine the behavior of an 'archive object' within the cluster. The archive cluster application provides object-based storage. Preferably, the application permanently associates metadata and policies with the raw archived data, which together comprise an archive object. Object policies govern the object's behavior in the archive. As a result, the archive manages itself independently of client applications, acting automatically to ensure that all object policies are valid.

A cluster recovery process is implemented across a set of distributed archives, where each individual archive is a storage cluster of preferably symmetric nodes. Each node of a cluster typically executes an instance of an application that provides object-based storage of fixed content data and associated metadata. According to the storage method, an association or 'link' between a first cluster and a second cluster is first established to facilitate replication. The first cluster is sometimes referred to as a 'primary' whereas the &#x201c;second&#x201d; cluster is sometimes referred to as a &#x201c;replica.&#x201d; Once the link is made, the first cluster's fixed content data and metadata are then replicated from the first cluster to the second cluster, preferably in a continuous manner. Upon a failure of the first cluster, however, a failover operation occurs, and clients of the first cluster are redirected to the second cluster. Upon repair or replacement of the first cluster (a &#x201c;restore&#x201d;), the repaired or replaced first cluster resumes authority for servicing the clients of the first cluster. This restore operation preferably occurs in two stages: a &#x201c;fast recovery&#x201d; stage that involves preferably &#x201c;bulk&#x201d; transfer of the first cluster metadata, following by a &#x201c;fail back&#x201d; stage that involves the transfer of the fixed content data. Upon receipt of the metadata from the second cluster, the repaired or replaced first cluster resumes authority for the clients irrespective of whether the fail back stage has completed or even begun.

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Arlington, MA, United States of America

Benjamin K D Bernhard