摘要:
A system and method for incremental change synchronization among multiple copies of data is disclosed. To achieve the synchronization a genera synchronization model is used. The synchronization model establishes a one-way data flow path to allow incremental changes to be transferred from a copy of data that incorporates the incremental changes to a copy of data that does not yet incorporate the incremental changes. To achieve this one-way data flow path, the synchronization model uses an agent, a data collector, and a data synchronizer. The data collector collects incremental changes transferred to it and applies the incremental changes to a copy of data. A data synchronizer transfers incremental changes to a data collector. An agent controls the synchronization process by making a connection between a data collector and a data synchronizer and then directing the data synchronizer to transfer data to the data collector. If bidirectional data flow is necessary to achieve synchronization between two copies of data, a one-way data flow path is established first in one direction and after all incremental changes have been passed in that direction, a data flow path is established in the opposite direction to pass incremental changes in the opposite direction.
摘要:
In an electronic mail system comprising a local computer that can be connected to a message server over a data link, mechanisms are provided to convert large identification codes used by the message server to store and access messages and folders into shorter identification codes used by the local computer to access locally stored copies of the messages or folders. The large server identification codes, including a 46-byte folder codes and 70-byte message codes, are converted using a conversion technique that operates in one of two modes, depending on whether the data link to a master conversion map on the message server is available and operative. In the first mode, to convert the codes to 8-byte codes, the technique uses a local cache that retains mapping information produced in conversions using the master conversion map. In the second mode, three types of local maps are implemented as B-trees are used to convert the codes first to the 8-byte codes and then to 4-byte codes. In a reverse conversion using one of the B-tree maps, a 4-byte code is converted back to a 46 or 70-byte code.
摘要:
Systems and methods of time based data expiration in a replication environment are presented. The systems and methods of the present invention allow different age limits to be set on each individual server in a network. A network can therefore be configured with some servers having no age limit and other servers having a wide range of differing age limits. Systems and methods for handling mixed data sets that include some data objects which are allowed to expire and some data objects which do not expire are also presented. In all cases, the time based data expiration systems and methods are designed to insure proper operation of the replication process and any associated data recovery process. Specifically, expired data will not be recovered via any data recovery mechanism and servers will not attempt to recover missing data from a server that has expired that data.
摘要:
A single processor/storage device provides multilingual support for a computer system. Information is divided into two parts. The first part is initially stored in a first character set, e.g., the character set in which it was created. A tag, identifying the character set, is associated with the first part. The second part is stored in a universal character set. The first part is converted to another character set only when requested. Indices may be generated from the second part using specified language sorting rules.
摘要:
A system and method for replica administration without data loss is disclosed. In a replication environment where data is replicated around a network and where any system can make changes to the data, data loss may occur if one copy of the data is deleted before changes made to that copy are replicated to other systems in the network. The present invention describes a robust administration environment which prevents inadvertent data loss by verifying that changes made to a local copy of the data reside on at least one other system in the network. The system and method of the present invention also provide a mechanism to allow an administrator to bypass such safeguards in appropriate circumstances in order to handle special cases such as total removal of the data from the network. The replica administration environment is implemented by defining various states that represent the level of participation in the replication of the data. For example, an active state can indicate full participation while a deleted state can indicate no participation. In addition to an active state and a deleted state, one or more intermediate states may be defined. The checks and safeguards can be performed in these intermediate states. In appropriate circumstances, an administrator may force the transition from certain of the intermediate states to either the active state in order to return a system to full participation or to the deleted state in order to bypass the safeguards of the present invention.
摘要:
Various exemplary metadirectories, systems and/or methods include delta information, error information and/or state information to facilitate metadirectory administration and/or operation. An exemplary metadirectory relies on a hologram and a plurality of deltas to represent information related to an object of a directory. Such an exemplary metadirectory may represent the object in association with one or more processing states based on the hologram and one or more of the plurality of deltas. Various other exemplary metadirectories, systems and/or methods are also disclosed.
摘要:
Described are mechanisms and techniques for enabling incremental non-chronological synchronization of namespaces. In an environment, entities must have unique names within a namespace and entities may only refer to entities that actually exist within the namespace. Synchronizing two such namespaces involves providing a mechanism for indicating that an entity has been created because a reference to that entity has been made even though that entity does not yet exist. At such time as the entity is formally created, the indication is removed. Synchronizing two such namespaces also involves providing a mechanism for indicating that an entity's unique name in the namespace has been compromised through the synchronization process.
摘要:
In one aspect, the disclosed technique detects common leading byte patterns in the integers so that these patterns need only be stored once in the encoded byte stream. Those integers that share a common leading byte pattern are stored in truncated form, without their common leading bytes. These truncated integers may themselves be further examined to determine if any of them share additional common leading bytes beyond those already detected. Thus, the technique lends itself naturally to description using the language of trees. Integers with a common leading byte pattern are stored as child nodes, their parent being the node containing the common byte pattern. Child nodes consist only of those bytes remaining after the initial byte pattern has been extracted; the greater the number of children, the greater are the efficiency gains. All the children of a given tree or subtree are similarly examined for common leading byte patterns, ignoring those bytes that are already accounted for in their ancestor nodes. In a second aspect, the disclosed technique makes use of "clustering", a second type of locality that is not reached by the interval concept. A cluster is a sequence of singleton integers that are very close together but do not form a contiguous interval. The technique recognizes that such a cluster can be compactly stored as a bitmap, in which each active bit ("1-bit") represents a member of the cluster. The choice of bitmap size (e.g., 1 byte, 2 bytes, etc.) can be calibrated to suit the clustering characteristics of the input data set.
摘要:
Exemplary methods, devices, systems, and/or storage media for organizational data management, including staging, synchronizing, and exporting of organizational data. Exemplary data aggregation rules specify methods for aggregating data from a remote repository. Schemas are exemplary rules configuration data structures having elements for associating processing data objects in a buffer space objects in a core space. The elements may also specify importing attributes into and exporting attributes from the core space.
摘要:
Systems and methods for extending a directory schema independent of schema modification are described. In one aspect, a directory schema data structure includes a flexible attribute data field. The flexible attribute data field identifies a complex data type. The complex data type is used to express one or more operational or data providing properties of a flexible attribute. The one or more operational or data providing properties are independent of the complex data type and independent of directory schema modification. The directory schema data structure also includes a flexible structural object content class to encapsulate the flexible attribute.