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UBSS Bns

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Emmanuel Fuchs
Emmanuel Fuchs

The Basic Name Server (BNS) provides a mapping between logical names (symbols and aliases) and corresponding items. BNS stores these mappings in a local database and distributes global mappings to other nodes. BNS notifies applications of changes to mappings and allows applications to look up items using logical names or modify name-item mappings through library functions.

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UBSS UNIX Based System Software BNS Basic system Name Server MCC/CPC/CIS
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 : piece of information identified with a logical name, which can be  Item either a symbol or an alias. : logical name for an item used to obtain or modify the  Symbol corresponding item. BNS is case sensitive in handling symbols. : kind of nickname for a symbol. An item can be obtained using  Alias the symbol or using the alias of a symbol. An alias may never refer to another alias. BNS is case sensitive in handling aliases. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 2
BNS : Indirection Level ALIAS SYMBOL ITEM 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 3
BNS : 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 4
BNS : model Logique Name Logical or Physical Attributes Updates Get Notification FIFO FPL 200.111.23.7 :: 109 :: TCP PRINTER /DEV/TTY1 ERROR /etc/log220895 /etc/log230895 ERROR Modify 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 5
BNS : Configuration NODE 1 NODE 2 NODE 3 BNS BNS BNS BNSIO store store store LAN 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 6
BNS : 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 7
BNS : Change Notification Item Change Alias Change Alias SYMBOL ITEM Attributs Change Notification } Change notification Alias Change Notification to FIFO 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 8
BNS 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 9
BNS library functions Retrieve name or alias Retrieve the corresponding item of a specified name. bns_get Retrieve the corresponding symbol of a specified alias. bns_get_alias Modify name or alias Modify the item of a specified name. bns_modify Modify the symbol of a specified alias. bns_modify_alias Enable/disable notification Enable/disable notification relative to creation,modification bns_notify and deletion of a specified name. Enable/disable notification relative to creation, modification bns_notify_alias and deletion of a specified alias.  Control BNS behavior Control or retrieve BNS behavior bns_control_node_access ( [dis]connection from its network access ). 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 10

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UBSS Bns

  • 1. UBSS UNIX Based System Software BNS Basic system Name Server MCC/CPC/CIS
  • 2. 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 : piece of information identified with a logical name, which can be  Item either a symbol or an alias. : logical name for an item used to obtain or modify the  Symbol corresponding item. BNS is case sensitive in handling symbols. : kind of nickname for a symbol. An item can be obtained using  Alias the symbol or using the alias of a symbol. An alias may never refer to another alias. BNS is case sensitive in handling aliases. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 2
  • 3. BNS : Indirection Level ALIAS SYMBOL ITEM 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 3
  • 4. BNS : 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 4
  • 5. BNS : model Logique Name Logical or Physical Attributes Updates Get Notification FIFO FPL 200.111.23.7 :: 109 :: TCP PRINTER /DEV/TTY1 ERROR /etc/log220895 /etc/log230895 ERROR Modify 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 5
  • 6. BNS : Configuration NODE 1 NODE 2 NODE 3 BNS BNS BNS BNSIO store store store LAN 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 6
  • 7. BNS : 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 7
  • 8. BNS : Change Notification Item Change Alias Change Alias SYMBOL ITEM Attributs Change Notification } Change notification Alias Change Notification to FIFO 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 8
  • 9. BNS 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. 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 9
  • 10. BNS library functions Retrieve name or alias Retrieve the corresponding item of a specified name. bns_get Retrieve the corresponding symbol of a specified alias. bns_get_alias Modify name or alias Modify the item of a specified name. bns_modify Modify the symbol of a specified alias. bns_modify_alias Enable/disable notification Enable/disable notification relative to creation,modification bns_notify and deletion of a specified name. Enable/disable notification relative to creation, modification bns_notify_alias and deletion of a specified alias.  Control BNS behavior Control or retrieve BNS behavior bns_control_node_access ( [dis]connection from its network access ). 01/04/2 Version 6 MCC/CPC/CIS UBSS/BNS 10