ubss bns

UBSSUBSSUNIXUNIX Based System SoftwareBased System Software

BNSBNSBasic system Name ServerBasic system Name Server

MCC/CPC/CIS

01/04/2004

UBSS/BNS 2MCC/CPC/CIS

Version 6

Basic system Name Server (BNS)Basic system Name Server (BNS)

The Basic system Name Server (BNS) is a facility to provide a mapping from a set of names to a set of corresponding items.

Some definitions of names

Item : piece of information identified with a logical name, which can be either a symbol or an alias.

Symbol : logical name for an item used to obtain or modify the corresponding item. BNS is case sensitive in handling symbols.

Alias : kind of nickname for a symbol. An item can be obtained using the symbol or using the alias of a symbol. An alias may never refer to another alias. BNS is case sensitive in handling aliases.

01/04/2004


Version 6

BNS : Indirection LevelBNS : Indirection Level

ALIASSYMBOL ITEM

01/04/2004


Version 6

BNS : ConceptsBNS : Concepts

Two types of aliases and symbols are known by BNS:Local aliases and symbols only known on the local node. They are not

distributed to other nodes. Global aliases and symbols distributed to other nodes (by mean of

CDC). A global alias may not reference a local symbol. A local alias may, however, reference a global symbol.

BNS is used by several UBSS services : IPC/FIFO services for the mapping of address, IOC_LPR_SERVER for logical names of printers, SCM for applicative state of the node.

BNS provides services for application processes.

01/04/2004


Version 6

BNS : modelBNS : modelLogical or Physical AttributesLogique Name

ERROR /etc/log230895

Updates Notification

FIFO FPL 200.111.23.7 :: 109 :: TCP

PRINTERERROR /etc/log220895

/DEV/TTY1

Modify

Get

01/04/2004


Version 6

BNS : ConfigurationBNS : Configuration

BNS

LAN

NODE 1 NODE 2 NODE 3

store

BNS

store

BNS

store

BNSIO

01/04/2004


Version 6

BNS : functionalitiesBNS : functionalities

The Basic system Name Server performs the following functions:Pre-processing of the Name Server File (NSF), which contains local

and global symbols and local and global aliases. The syntax and semantics of the NSF contents are checked. BNS exits when an error is detected in the NSF.

Creates a local database containing the names specified in the NSF and the global names received from other nodes.

Distributes initialized, modified and deleted global symbols and aliases.Maintains the local BNS database.Executes the requests issued by applications by means of the BNS

library functions.Notifies applications when names or aliases are initialized, modified or

deleted.Executes the BNS specific commands of BNSIO.

01/04/2004


Version 6

BNS : Change NotificationBNS : Change Notification

Alias SYMBOL ITEM

}

Alias ChangeItem Change

Changenotification to FIFOAlias Change Notification

Attributs Change Notification

01/04/2004


Version 6

BNSBNS

The Name Server File (NSF) : initialization file for BNS which defines all symbols and aliases. used to fill the BNS database. In this file only a part of the filling of

the local database is specified, since the local BNS database is also filled with global symbols and aliases which were inserted at remote nodes.

It is impossible for application programs to insert new symbols or aliases in the BNS database dynamically

BNSIO is a tool for an interactive user to inspect, modify or delete symbol or aliases known by BNS.

01/04/2004


Version 6

BNS library functionsBNS library functions

Retrieve name or aliasbns_get Retrieve the corresponding item of a specified name.bns_get_alias Retrieve the corresponding symbol of a specified alias.

Modify name or aliasbns_modify Modify the item of a specified name.bns_modify_alias Modify the symbol of a specified alias.

Enable/disable notificationbns_notify Enable/disable notification relative to creation,modification and deletion of a specified name.

bns_notify_alias Enable/disable notification relative to creation, modification and deletion of a specified alias.

Control BNS behaviorbns_control_node_access Control or retrieve BNS behavior

( [dis]connection from its network access ).

ubss bns

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