The part of the DSA that establishes the connection to the communications network.


DFS: A program that finds and attempts to repair inconsistencies in DCE LFS aggregates. The Salvager is similar to the fsck program in other, non-LFS file systems.

Scheduled Replication

DFS: A method of updating read-only copies of filesets. Scheduled Replication is automatically performed by the Replication Server at specified intervals. See also Release Replication, replication.


The directory schema is the set of rules and constraints concerning the DIT structure, object class definitions, attribute types, and syntaxes that characterize the DIB. See also attribute schema.

schema entry

A record containing the identifiers and characteristics of an attribute type. A schema entry is essentially an attribute type definition.

schema object

The registry data node, with the well-known name xattrschema (under the security junction point, typically /.: /sec), containing the attribute schema information. (Also called attribute schema object.)


DFS: A program that can be run on any machine configured as a DFS client. It monitors the File Exporter running on designated File Server machines by periodically collecting statistics and displaying them in a graphical format. See also attention threshold, basename, disk usage.


To encrypt a record containing several fields in such a way that the fields cannot be modified without either knowledge of the encryption key or leaving evidence of tampering.

secondary representation

A second form, an alternative to the primary representation, in which the client can supply an attribute value to the service.

secondary site

DFS: A read-only site that receives updates to its copy of a DFS administrative database from the Ubik synchronization site. There can be more than one secondary site. If necessary, a secondary site can be elected to assume the role of synchronization site. See also synchronization site, Ubik.

secret key

A long-lived encryption key known to more than one principal, usually two. In DCE, each secret key is known to the Authentication Service and one other principal.


Zero or more contiguous elements of a string.

self-pointing type

RPC: A data type containing a pointer member that can point directly or indirectly to another item of the same type.

SEP line

In an event class file, an entry that specifies the prefixes of the event numbers in the file. This is an optional entry and is used to speed up the search for events in event class files.


RPC: The party that receives remote procedure calls. A given application can act as both an RPC server and an RPC client. See also client.

CDS: A node running CDS server software. A CDS server handles name-lookup requests and maintains the contents of the clearinghouse or clearinghouses at its node.

DTS: A system or process that synchronizes with its peers and provides its clock value to clerks and their client applications.

DFS: A provider of resources or services. See also client.

GDS: The server consists of a DSA, which accesses the database, and an S-stub, which handles the connection over the communications network for responding to remote clients and accessing remote servers.

server addressing information

RPC: An RPC protocol sequence, network address, and endpoint that represent one way to access an RPC server over a network; a part of server binding information. See also binding information, endpoint, network address, RPC protocol sequence.

server application thread

RPC: A thread executing the server application code that initializes the server and listens for incoming calls. See also application thread , client application thread, local application thread, RPC thread.

server binding information

RPC: Binding information for a particular RPC server. See also binding information, client binding information .

server entry

RPC: A name service entry that stores the binding information associated with the RPC interfaces of a particular RPC server and also the object UUIDs for any objects offered by the server. See also binding information, NSI binding attribute, object, NSI object attribute , RPC interface.

DFS: A unique identifier for a server machine in the FLDB.

server instance

RPC: A server executing in a specific address space; multiple server instances can coexist on a single system. See also server.

server machine

DFS: A machine that runs one or more DFS server processes. Depending on the process it runs, a server machine can be further classified as a File Server machine, a System Control machine, a Binary Distribution machine, a Fileset Database machine, or a Backup Database machine. See also client machine.

server module

DFS: The part of the DFS Cache Manager that provides information for tracking server activity.

server portion of Update Server

See upserver.

server process

DFS: A process that runs on server machines, providing services such as storing and transferring files or tracking fileset locations to clients. See also server machine.

server stub

RPC: The surrogate calling code for an RPC interface that is linked with server application code containing one or more sets of remote procedures (managers) that implement the interface. See also client stub, manager, stub.


RPC: An integral set of RPC interfaces offered together by a server to meet a specific goal. See also RPC interface.

service controls

A group of parameters, applied to all directory operations, that direct or constrain the provision of the service.


A sequence of directory operations requested by a particular user of a particular DUA. The operations use the same session OM object.

session key

Used in Kerberos specifications; acronym for "conversation key." See also conversation key.


In event numbers, the component of the event number that identifies a set of events to which the Audit event belongs. In event class numbers, the component of the event class number that identifies a set of event classes to which the event class belongs.

shadow entry

A copy entry of an object. This is an entry of an object in a DSA other than the master DSA.


Threads: To wake only one thread waiting on a condition variable.


Information is digitally signed by appending to it an enciphered summary of the information. This is used to ensure the integrity of the data, the authenticity of the originator, and the unambiguous relationship between the originator and the data.

simple bnode

DFS: A bnode that manages a single process that is to be kept running at all times. See also bnode, Basic OverSeer Server .

simple name

One element in a CDS full name. Simple names are separated by / (slashes).

simple object

An object that does not hold other objects. For example, a file is a simple object. See also container object.

simple process

DFS: A type of process defined in a server machine's BosConfig file. It runs continuously and can be stopped and restarted independently of any other process on its machine. See also cron process, simple bnode.


DFS: The location of a fileset expressed as a specific File Server machine and aggregate.

site count

DFS: A count of the number of sites where the read/write and read-only versions of a fileset reside.

site flags

DFS: A term for the flags associated with each site definition in an FLDB entry. The flags can indicate the fileset type (read/write or read-only) and other administrative information.


The time difference between two clocks or clock values.


A process by which CDS makes the data consistent in all replicas of a particular directory. CDS collects all changes made to the master replica since the last skulk completed, and disseminates the changes from the up-to-date replica to all other existing replicas of the directory. All replicas of a directory must be available for a skulk to be considered successful. If a skulk fails, CDS informs you of the replicas that it could not reach.

slave replica

An instance of a Security Server that accepts only queries to its associated registry database. Slave replicas are updated by the master replica. Each cell can have many slave replicas. See also master replica.

soft link

A pointer that provides an alternate name for an object entry, directory, or other soft link in the namespace. A soft link can be permanent or it can expire after a period of time that you specify. The CDS server also can delete it automatically after the name that the link points to is deleted.

source fileset

See read/write fileset.


The attribute types that can appear in an instance of a given class, but not in an instance of its superclasses.


See Stub Programming Interface.


See Structure Rule Table.

status flag

DFS: In a BosConfig file, the flag that tells the BOS Server whether a server process should be running. In an FLDB entry, the flag that indicates whether a fileset of each possible type (read/write, read-only, and backup) actually exists at a site. In a fileset header, a flag that indicates whether the contents of the fileset are accessible via the File Server machine.

status token

DFS: A token that grants access to the status information associated with a file or directory. Read and write status tokens are available.


An ordered sequence of bits, octets, or characters, accompanied by the string's length.

Structure Rule Table (SRT)

A recurring attribute of the directory schema with the description of the permitted structures of distinguished names.


RPC: A code module specific to an RPC interface that is generated by the DCE IDL compiler to support remote procedure calls for the interface. RPC stubs are linked with client and server application and hide the intricacies of remote procedure calls from the application code. See also client stub, server stub.

Stub Programming Interface (SPI)

A private RPC runtime interface whose routines are unavailable to application code.


One of the classes, designated as such, whose attribute types are a superset of those of another class.


An object that is in a subordinate relationship to a given object.


In the DIT, an entry is subordinate to another if its distinguished name includes that of the other as a prefix.


One of the classes, designated as such, whose attribute types are a subset of those of another class.


In the DIT, an entry is superior to another if its distinguished name is included as a prefix of the distinguished name of the other. Each entry has exactly one immediate superior.


An object that is in a superior relationship to a given object.


DTS: The process by which a DTS entity requests clock values from other systems, computes a new time from the values, and adjusts its system clock to the new time.

synchronization list

DTS: The list of servers that a DTS entity has discovered; the entity sends requests for clock values to the servers on the list.

synchronization site

DFS: The one Ubik site that accepts changes to its copy of a DFS administrative database and distributes them to the secondary sites. The synchronization site can change as necessary. See also secondary site, Ubik.



1. An OM syntax is any of various categories into which the object management specification statically groups values on the basis of their form. These categories are additional to the OM type of the value.

2. A category into which an attribute value is placed on the basis of its form. See also attribute syntax.

syntax template

A lexical construct containing an asterisk from which several attribute syntaxes can be derived by substituting text for the asterisk.

System Control machine

DFS: The machine that distributes common configuration files to other server machines in the cell or administrative domain. The System Control machine runs the server portion of the Update Server for this purpose. See also server machine, Update Server, upserver.

system time

The time value that the operating system maintains according to its reading of the system's hardware clock.