Name service caching daemon

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The name service caching daemon , shortly nscd is a daemon in various Unix -like operating systems , including Linux and Solaris , whose task is to name queries such as queries to / etc / passwd , / etc / hosts , / etc / group and DNS queries that are made using libc functions to cache , the performance increase of a system.

The configuration of the nscd is done via the file /etc/nscd.confin which the settings for the various caches for the user, group or name databases can be made, e.g. B. positive-time-to-liveetc.

The use of an nscd is usually only worthwhile if a system either has very large user databases or can only query them via a network . Under such conditions, massive hard disk and network resources can be saved by using the nscd , while at the same time increasing the speed of name queries. On the other hand, an nscd does not slow down a system (or at least does not slow it down significantly) without such conditions, so that it is worthwhile to run an nscd on almost all system configurations.

Access to the system databases in /etc/passwd, /etc/groupand /etc/hosts, which are carried out via the following (g) libc functions, are specifically cached :

  • getpwnam()
  • getgrnam()
  • gethostbyname()(which is, however, obsolete )
  • getaddrinfo()
  • getnameinfo()

See also

Web links

Individual evidence

  1. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/getnameinfo.3.html
  2. ↑ Archived copy ( Memento of the original from September 18, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.linux.ncsu.edu
  3. ↑ https://www.kernel.org/doc/man-pages/online/pages/man8/nscd.8.html
  4. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/getpwuid.3.html
  5. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/getgrgid.3.html
  6. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/gethostbyname.3.html
  7. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/getaddrinfo.3.html
  8. ↑ https://www.kernel.org/doc/man-pages/online/pages/man3/getnameinfo.3.html