YPFILES(4) — Series 300 Only

NAME

ypfiles − the Yellow Pages database and directory structure

DESCRIPTION

The Yellow Pages (YP) network lookup service uses databases in the directory hierarchy under /usr/etc/yp. (Note: a symbolic link exists from /etc/yp to /usr/etc/yp.) These databases exist only on machines that act as YP servers. A database consists of two files created by makedbm(1M). One has the filename extension .pag and the other has the filename extension .dir. For example, the database named netgroup is implemented by the pair of files netgroup.pag and netgroup.dir. A database served by the YP is called a YP map.

A YP domain is a named set of Yellow Pages maps. Each YP domain is implemented as a subdirectory of /usr/etc/yp (whose name is the domain name) and contains the maps for that domain. Any number of YP domains can exist, and each can contain any number of maps.

Besides the databases contained in /usr/etc/yp/<domain>, master YP servers have files named <general_YP_mapname>.time that reside there, too. These files are merely empty files whose times of last modification are compared to those of the ASCII files from which the maps are built. The ypmake(1M) script performs these comparisons to determine whether the maps are current. The general_YP_mapname designation is described further in the following FILES section.

The YP lookup service does not require maps, although maps may be required for the normal operation of other parts of the system. The list of maps a YP server provides access to is neither restricted nor must it be all-inclusive. If a map exists in a given domain and a client asks about it, the YP serves it. For a map to be consistently accessible, it must exist on all YP servers that serve the domain. To provide data uniformity between the replicated maps, make an entry to run ypxfr(1M) periodically in root’s crontab(1M) file on each server. More information on this topic is in yppush(1M) and ypxfr(1M).

YP maps contain two special key-value pairs. The first key, YP_LAST_MODIFIED, has a 10-character (ASCII) order number as a value. The order number is the time(2) in seconds when the map was built. The second key is YP_MASTER_NAME, whose value is the host name of the map’s master YP server. The makedbm(1M) command generates both key-value pairs automatically. The ypxfr(1M) command uses these values when it transfers a map from one YP server to another.

Generate and modify YP maps only on the master server. They are copied to the slaves using ypxfr(1M) to avoid potential byte-ordering problems among YP servers running on machines with different architectures and to minimize the disk space required for the databases. The YP databases can be created initially for both masters and slaves by using ypinit(1M).

After the servers’ databases are created, the contents of some maps will change. Generally, an ASCII source version of each database exists on the master and is changed with a text editor. The YP map is rebuilt to include the changes and propagated from the master to the slaves by running the shell script ypmake(1M).

All standard YP maps are built by commands contained in the ypmake(1M) script; if you add a non-standard YP map, edit this script to support the new map. (The standard YP maps are discussed in the following FILES section.) The ypmake(1M) script uses makedbm(1M) to generate the YP maps on the master and may run yppush(1M) to copy the rebuilt maps to the slaves. The yppush(1M) command refers to the contents of the map named ypservers that contains the host names of all YP servers for the specific domain. For more information, see ypmake(1M), yppush(1M), and ypxfr(1M).

DEPENDENCIES

Series 300

If you want to create a new non-standard map for the Yellow Pages, its name cannot exceed 10 characters in length. This rule exists because the Series 300 has a 14-character length restriction on filenames and makedbm(1M) adds .dir and .pag suffixes to any mapname.

The following table describes the translation of standard YP mapnames to shorter names for storage on a Series 300. The standard mapnames should be used by YP clients on HP machines when making requests, regardless of which machine is the YP server.

             Standard YP        Series 300
               Mapname            Mapname

            mail.aliases        mail.alias
            ethers.byaddr       ether.byad
            ethers.byname       ether.byna
            group.bygid         group.bygi
            group.byname        group.byna
            hosts.byaddr        hosts.byad
            hosts.byname        hosts.byna
            netgroup            netgroup
            netgroup.byhost     netgr.byho
            netgroup.byuser     netgr.byus
            networks.byaddr     netwk.byad
            networks.byname     netwk.byna
            passwd.byname       passw.byna
            passwd.byuid        passw.byui
            protocols.byname    proto.byna
            protocols.bynumber proto.bynu
            rpc.bynumber        rpc.bynu
            services.byname     servi.byna
            ypservers           ypservers

AUTHOR

Sun Microsystems, Inc.

FILES

The following text presents information about the standard Yellow Pages maps.

The General YP Mapname column lists names for sets of YP maps; the sets include adjacent entries from the Standard YP Mapname column.

The ASCII Source column lists the ASCII files from which the maps are usually built on HP master YP servers. The ypmake(1M) script permits the source directory, or file in the case of the passwd maps, to vary.

The Standard YP Mapname column lists names by which maps are stored on YP servers and referred to by YP clients.

     General YP                     Standard YP
      Mapname     ASCII Source        Mapname

      aliases     *                 mail.aliases
      ethers      *                 ethers.byaddr
                                    ethers.byname
      group       /etc/group        group.bygid
                                    group.byname
      hosts       /etc/hosts        hosts.byaddr
                                    hosts.byname
      netgroup    /etc/netgroup     netgroup
                                    netgroup.byhost
                                    netgroup.byuser
      networks    /etc/networks     networks.byaddr
                                    networks.byname
      passwd      /etc/passwd       passwd.byname
                                    passwd.byuid
      protocols   /etc/protocols    protocols.byname
                                    protocols.bynumber
      rpc         /etc/rpc          rpc.bynumber
      services    /etc/services     services.byname
      ypservers   **                ypservers

*These databases are not built on HP master Yellow Pages servers. However, if an HP machine is a slave to a master YP server that creates and distributes these databases, the HP slave YP server will store these databases. It is suggested that if you have a non-HP machine that requires these maps, make that machine the master YP server. By doing this, the maps should be built as needed.

**No ASCII source exists for the ypservers database. It is created from responses provided by the user of ypinit(1M) on the master YP server, and it has no matching ypservers.time file.

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