In an information management system, relevant policies are deployed to targets while policies which are not relevant are not. By deploying relevant policies, this reduces the amount of space requirements at the target to store the policies and the amount of data that needs to be sent to the target. Also, execution speed at the target may increase since the target does not need to evaluate policies that are not relevant.

Techniques and system to deploy policies intelligently

Systems and methods are provided for managing asynchronous replication in a distributed database environment, while providing for scaling of the distributed database. A cluster of nodes can be assigned roles for managing partitions of data within the database and processing database requests. In one embodiment, each cluster includes a node with a primary role to process write operations and mange asynchronous replication of the operations to at least one secondary node. Each cluster or set of nodes can host one or more partitions of database data. Collectively, the cluster or set of nodes define a shard cluster that hosts all the data of the distributed database. Each shard cluster, individual nodes, or sets of nodes can be configured to manage the size of any hosted partitions, splitting database partitions, migrating partitions, and/or managing expansion of shard clusters to encompass new systems.

Large distributed database clustering systems and methods

Provided are systems and methods for managing asynchronous replication in a distributed database environment, wherein a cluster of nodes are assigned roles for processing database requests In one embodiment, the system provides a node with a primary role to process write operations against its database, generate an operation log reflecting the processed operations, and permit asynchronous replication of the operations to at least one secondary node In another embodiment, the primary node is the only node configured to accept write operations Both primary and secondary nodes can process read operations Although in some to settings read requests can be restricted to secondary nodes or the primary node In one embodiment, the systems and methods provide for automatic failover of the primary node role, can include a consensus election protocol for identifying the next primary node Further, the systems and methods can be configured to automatically reintegrate a failed primary node

Method and apparatus for maintaining replica sets

According to one aspect, provided is a horizontally scaled database architecture. Partition a database enables efficient distribution of data across a number of systems reducing processing costs associated with multiple machines. According to some aspects, the partitioned database can be manages as a single source interface to handle client requests. Further, it is realized that by identifying and testing key properties, horizontal scaling architectures can be implemented and operated with minimal overhead. In one embodiment, databases can be partitioned in an order preserving manner such that the overhead associated with moving the data for a given partition can be minimized during management of the data and/or database. In one embodiment, splits and migrations operations prioritize zero cost partitions, thereby, reducing computational burden associated with managing a partitioned database.

System and method for optimizing data migration in a partitioned database

In an information management system, policies are deployed to targets and targets can evaluate the policies whether they are connected or disconnected to the system. The policies may be transferred to the target, which may be a device or user. Relevant policies may be transferred while not relevant policies are not. The policies may have policy abstractions.

Techniques of Transforming Policies to Enforce Control in an Information Management System

A method and apparatus to protect memory consistency in a multiprocessor computing system are described, in particular relating to program code conversion such as dynamic binary translation. The exemplary system provides a memory, processors and a controller/translator unit (CTU) arranged to convert subject code into at least first and second target code portions executable on the processors. The CTU comprises an address space allocation unit to provide virtual address space regions and direct the target code portions to access the memory therethough; a shared memory detection unit to detect a request to access a shared memory area, accessible by both target code portions, and to identify at least one group of instructions in the first target code portion which access the shared memory area; and a memory protection unit to selectively apply memory consistency protection in relation to accesses to the shared memory area by the identified group of instructions.

Memory consistency protection in a multiprocessor computing system

A dynamic binary translator 19 converts a subject program 17 into target code 21 on a target processor 13 . For a multi-threaded subject environment, the translator 19 provides a global token 501 common to each thread 171, 172 , and one or more sets of local data 502 , which together are employed to coordinate access to a memory 18 as a shared resource. Adjusting the global token 501 allows the local datastructures 502 a,b in each thread to detect potential interference with the shared resource 18.

Converting program code with access coordination for a shared memory

A translator apparatus is provided with both program code (17) interpreting and translating functionality, where subject program code (17) is interpreted rather than being translated in those situations where interpretation of the subject program code (17) is determined to be more beneficial. The translator (19) applies an interpreting algorithm to determine whether a basic block of subject program code (17) should be interpreted or translated. A particular subject of instructions supported by the interpreter functionality is initially selected from an entire instruction set for the subject program code (17). A basic block will be interpreted 1) if all of the instructions within a basic block are determined to be within the subset of instructions supported by the interpreter functionality, and 2) if an execution count of the basic block is below a translation threshold. If either of these two conditions are not satisfied, then the basic block is translated by the translator (19).

Method and apparatus for performing interpreter optimizations during program code conversion

An improved method and apparatus for performing program code conversion is provided and, more particularly, for generating improved intermediate representations for use in program code conversion During program code conversion, a partial dead code elimination optimization technique is implemented to identify partially dead register definitions within a block of program code being translated The partial dead code elimination is an optimization to the intermediate representation in the form of code motion for blocks of program code ending in non-computed branches or computed jumps, where target code for all dead child nodes of a partially dead register definition is prevented from being generated and target code for partially dead child nodes of a partially dead register definition is delayed from being generated until after target code is generated for all fully live child nodes for the partially dead register definition

Method and apparatus for performing lazy byteswapping optimizations during program code conversion

Execution control techniques are described for use in a translator that converts subject code into target code. The translator includes a translator trampoline function that is called from a translator run loop and which in turn calls either to a translator code generator to generate target code, or else calls previously generated target code for execution. Control then returns to the translator trampoline function to make a new call, or returns to the translator run loop. Other aspects include making context switches through the trampoline function and setting first and second calling conventions either side of the trampoline function. Jumping directly or indirectly between target code blocks during execution is also described.

Gavin Barraclough

Papers

Memory consistency protection in a multiprocessor computing system

Converting program code with access coordination for a shared memory

Method and apparatus for performing interpreter optimizations during program code conversion

Method and apparatus for performing lazy byteswapping optimizations during program code conversion

Execution control during program code conversion