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Network Information Services (NIS and NIS+) Guide

Troubleshooting Slow Performance and System Hang Problems

This section describes common slow performance and system hang problems. Symptoms appear as error messages with operative clauses such as:

"Busy try again later"

"Not responding"

Other common symptoms include:


Attention: When someone has issued an nisping or nisping -C command, or the rpc.nisd daemon is performing a checkpoint operation and the system seems to hang, do not reboot. Do not issue more nisping commands. You may have corrupted information in the NIS+ domain.

After issuing an nisping or nisping -C command, the server can become sluggish and not immediately respond to other commands. In a large namespace, nisping commands can take a noticeable amount of time to complete. Delays caused by nisping commands are multiplied if you, or someone else, enter several such commands at one time. Do not reboot. This kind of problem solves itself. Wait until the server finishes performing the command.

During a full master-replica resync, the involved replica server is taken out of service until the resync is complete. Do not reboot. Wait for the resync to complete.

Variable NIS_PATH

Make sure that your NIS_PATH variable is set to something clean and simple, such as the default: org_dir.$:$. A complex NIS_PATH, particularly one that itself contains a variable, will slow your system and may cause some operations to fail. (See NIS_PATH Environment Variable for more information.)

Note: Do not use nistbladm to set nondefault table paths. Nondefault table paths slow performance.

Table Paths

Do not use table paths because they will slow performance.

Too Many Replicas

Too many replicas for a domain can degrade system performance during replication. There should be no more than 10 replicas in a given domain or subdomain. If you have more than five replicas in a domain, try removing some of them to see if that improves performance.

Recursive Groups

A recursive group is a group that contains the name of some other group. While including other groups in a group reduces your work as system administrator, doing so slows down the system. You should not use recursive groups.

Large NIS+ Database Logs at Start-up

When rpc.nisd starts, it goes through each log. If the logs are long, this process could take a long time. If your logs are long, you may want to checkpoint them using nisping -C before starting rpc.nisd.

The Master rpc.nisd Daemon Died

If you used the -M option to specify that your request be sent to the master server, and the rpc.nisd daemon has died on that machine, you will get a "server not responding" type error message and no updates will be permitted. (If you did not use the -M option, your request will be automatically routed to a functioning replica server.) Using uppercase letters in the name of a home directory or host can sometimes cause rpc.nisd to die.

First make sure that the server itself is up and running. If it is, run ps -ef | grep rpc.nisd to see if the daemon is still running.

If the daemon has died, restart it. If rpc.nisd frequently dies, contact your service provider.

No nis_cachemgr

If it takes too long for a machine to locate namespace objects in other domains, nis_cachemgr is probably not running. Do the following:

  1. Run ps -ef | grep nis_cachemgr to see if it is still running.
  2. Start nis_cachemgr on that machine.

Server Very Slow at Startup After NIS+ Installation

If a server performs slowly and sluggishly after using the NIS+ scripts to install NIS+, you probably did not run nisping -C -a after running the nispopulate script.

Run nisping -C -a to checkpoint the system as soon as you are able to do so.

niscat Returns: Server busy. Try Again

If you run niscat and get an error message indicating that the server is busy, either the server is busy with a heavy load (such as when doing a resync) or the server is out of swap space.

Run lsps -a to check your server's swap space.

You must have adequate swap and disk space to run NIS+. If necessary, increase your space.

NIS+ Queries Hang After Changing Host Name

Setting the host name for an NIS+ server to be fully qualified is not recommended. If you do so, and NIS+ queries then hang with no error messages, check that fully qualified host names meet the following criteria:

Kill the NIS+ processes that are hanging and then kill rpc.nisd on that host or server. Rename the host to match the requirements listed above (use SMIT or the hostname command). Then reinitialize the server with nisinit. (If queries still hang after you are sure that the host is correctly named, check other problem possibilities in this section.)

Note: If you started rpc.nisd with the -B option, you must also kill the rpc.nisd_resolv daemon.

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