Oracle Net Services

In the field of database computing, Oracle Net Services consists of sets of software which enable client applications to establish and maintain network sessions with Oracle Database servers. Since Oracle databases operate in and across a variety of software and hardware environments, Oracle Corporation supplies high-level transparent networking facilities with the intention of providing networking functionality regardless of differences in nodes and protocols.

Terminology
  • network service name (NSN): "[a] simple name for a service that resolves to a connect descriptor"[1] For example: sales.acme.co.uk

Components

Oracle Corporation defines Oracle Net Services as comprising:[2]

  • Oracle net
  • listener
  • Oracle Connection Manager
  • Oracle Net Configuration assistant
  • Oracle Net Manager

Oracle Net

Oracle Net,[3] a proprietary networking stack, runs both on client devices and on Oracle database servers in order to set up and maintain connections and messaging between client applications and servers. Oracle Net (formerly called "SQL*Net" or "Net8"[4]) comprises two software components:

  1. Oracle Net Foundation Layer: makes and maintains connection sessions. The Oracle Net Foundation Layer establishes and also maintains the connection between the client application and server. It must reside on both the client and server for peer-to-peer communication to occur.
  2. Oracle Protocol Support: interfaces with underlying networking protocols such as TCP/IP, named pipes, or Sockets Direct Protocol (SDP).

The listener

The listener process(es) on a server detect incoming requests from clients for connection - by default on port 1521[5] - and manage network-traffic once clients have connected to an Oracle database. The listener uses a configuration-file - listener.ora - to help keep track of names, protocols, services and hosts. The listener.ora file can include three sorts of parameters:[6]

  1. listener-address entries
  2. SID_LIST entries
  3. control entries

Apart from pre-defined and known statically-registered databases, a listener can also accept dynamic service registration from a database.

Oracle Connection Manager

The Oracle Connection Manager (CMAN) acts as a lightweight router for Oracle Net packets.[7]

Oracle Net Manager

Oracle Net Manager, a GUI tool, configures Oracle Net Services for an Oracle home on a local client or server host.[8] (Prior to Oracle 9i known as "Net8 Assistant".[9])

Associated software

Utilities and tools
  • tnsping: determines the accessibility of an Oracle net service.[10]

Software suites

Oracle software integrating closely with and/or depending on Oracle Net Services includes:

See also

References
  • Arun Kumar, John Kanagaraj and Richard Stroupe: Oracle Database 10g Insider Solutions. Sams, 2005. ISBN 978-0-672-32791-9

Footnotes
  1. Johnston, Caroline (April 2014). "Oracle Database Net Services Reference, 12c Release 1 (12.1)". docs.oracle.com. Oracle. Retrieved 2014-06-04. network service name[:] A simple name for a service that resolves to a connect descriptor. Users initiate a connect request by passing a user name and password along with a network service name in a connect string for the service to which they want to connect: CONNECT username/password@net_service_name
  2. Glossary:Oracle Net Services, retrieved 2007-12-03
  3. Introduction to Oracle Net Services" in Oracle Database Net Services Administrator's Guide 11g Release 1 (11.1), retrieved 2008-01-05
  4. Greenwald, Rick; Stackowiak, Robert; Stern, Jonathan (2007). Oracle Essentials: Oracle Database 11g (4th ed.). O'Reilly Media, Inc. p. 13. ISBN 9780596555337. Retrieved 2014-05-07. Oracle's network interface, Oracle Net, was formerly known as Net8 when used in Oracle8, and SQL*Net when used with Oracle7 and previous versions of Oracle.
  5. Rajan, Claire (2006). Oracle 10g Database Administrator II: Backup/Recovery and Network Administration. Cengage Learning. p. 561. ISBN 9781418836641. Retrieved 2014-12-08. By default, the listener listens on port 1521 for clients requiring database access.
  6. Toledo, Hugo; Gennick, Jonathan (2001). Oracle Net8: Configuration and Troubleshooting. O'Reilly series (1 ed.). O'Reilly Media, Inc. p. 71. ISBN 9781565927537. Retrieved 2013-08-28.
  7. Elizabeth Hanes Perry; et al. (June 2004). "Oracle Database JDBC Developer's Guide and Reference" (PDF). Oracle Database JDBC Developer's Guide and Reference 10g Release 1 (10.1). Oracle Corporation. pp. 24–2. Retrieved 2010-02-12. The Oracle Connection Manager is a lightweight, highly-scalable program that can receive Oracle Net packets and re-transmit them to a different server. To a client running Oracle Net, the Connection Manager looks exactly like a database server.
  8. Strohm, Richard; et al. (July 2008). Oracle Database Net Services Administrator's Guide 11g Release 1 (11.1). Oracle Corporation. Retrieved 2010-02-15. Oracle Net Manager enables you to configure Oracle Net Services for an Oracle home on a local client or server host.
  9. Greenwald, Rick; Stackowiak, Robert; Stern, Jonathan (February 2004) [1999]. Russell, Deborah (ed.). Oracle essentials: Oracle Database 10g (3 ed.). O'Reilly. p. 62. ISBN 0-596-00585-7. In Oracle8, Oracle provided a GUI utility called the Net8 Assistant used to create the various configuration files required for Net8; this utility was renamed the Oracle Net Manager with the Oracle 9i release.
  10. Mishra, Sanjay (2004). Oracle utilities: pocket reference. O'Reilly Series Pocket Reference. O'Reilly Media. p. 106. ISBN 978-0-596-00899-4. Retrieved 2010-02-11. Use tnsping to determine whether an Oracle Net service can be successfully reached [...] specify a protocol address instead of a net service name to test connectivity to an Oracle Names server or Connection Manager instance.
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