Machine Types and Daemons

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Solaris™ Operating Environment Boot Camp
By David Rhodes, Dominic Butler
Table of Contents
Chapter 12.  Naming Services and NIS


Earlier in the chapter we mentioned the different NIS machine configurations that are available. Let's look at them in more detail now and also see the processes that run on each type.

Master Server

There is one master server per NIS domain, and it's always the first machine to be configured whenever the domain is created. The master's local /etc files are the ones used to generate the NIS maps, which are all built and stored on the master. (The NIS master doesn't have to use the /etc directory on the master, but suffice it to say the master houses the text files which are used to generate the NIS maps.)

Slave Server

Slave servers are used to provide redundancy should the main server fail. They will also add a degree of load balancing, as clients can connect to these as they would the master server. We've already said that slaves are not necessarily required, but there are usually a number configured on the network.

Each slave contains backup copies of the NIS maps, which are automatically "pushed" out and downloaded from the master server whenever any changes are made.

Client

Clients are the machines that access the NIS servers whenever they require information, as clients don't store any NIS maps themselves. The type of task that would request this information would be a user logging on to a machine (the system needs to check that it is a valid user).

Booting and Binding

A number of processes that are part of the NIS service are normally started at boot-time using a command called ypstart. Table 12.6 shows which these are, and which one is started on each type of system.

Table 12.6. NIS Processes

Process

Machine Type

ypxfrd

Master

rpc.yppasswdd

Master

rpc.ypudated

Master

ypserv

Master, Slave

ypbind

Master, Slave, Client

Let's briefly work through these to show how the client-server communication works for each type of machine.

Ypserv

This daemon runs on both masters and slaves. It is responsible for reading information from its local version of the NIS maps and passing this data back to the client daemon (ypbind).

Ypbind

This is the client process and runs on all machines, including servers. It connects to a ypserv daemon (normally the first one that responds) to request data. For master or slave servers, this normally means that ypbind will often receive a response back from its own ypserv daemon first.

This is known as "binding." Once this has been performed, ypbind will create a file in the binding directory that contains the name of the server it has successfully bound to. In our case, the binding file would be /var/yp/binding/nis.solarisbootcamp.com/ypservers.

On subsequent reboots, ypbind will try to rebind to the same server and only try another should the server fail or it is told to bind elsewhere.

Ypxfrd

This daemon runs on the master server. Its job is to perform high-speed map transfers to the slave servers.

Rpc.ypupdated

This daemon runs on the master server, where it is used to update the public-key map and any others that are referred to in the file /var/yp/updaters.

Rpc.yppasswd

This daemon runs on the master server. It allows users to alter their passwords on any machine and remake the password map.


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    Solaris Operating Environment Boot Camp
    Solaris Operating Environment Boot Camp
    ISBN: 0130342874
    EAN: 2147483647
    Year: 2002
    Pages: 301

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