Configuration of BindResolversTest

This test monitors the queries sent/forwarded by the resolver program, and measures the average round trip time of the queries. Administrators are alerted if even one query registers an abnormally high round trip time. Query failures are also brought to the immediate attention of administrators, so that they can investigate the reason for the same and fix it. In addition, the test also tracks the responses received by the resolver program to queries it forwarded. In the process, the test sheds light on error responses and the probable reason for those errors.

The default parameters associated with this test are as follows:

• The TEST PERIOD list box helps the user to decide how often this test needs to be executed.

• In the HOST text box, the host for which the test is to be configured has to be specified.

• In the PORT text box, specify the port at which the specified host listens to. By default, this is 53.

• To monitor BIND DNS, this test uses a name server control utility in bind called Remote Name Daemon Control (RNDC). RNDC is a command line utility that allows command line control of the administration and operations of a name server, both locally and remotely. Periodically, this test runs the rndc stats command of this utility to pull metrics of interest. To enable the test to run this command, configure the full path to the folder where RNDC is located, against the PATH OF RNDC parameter. The default location of RNDC is /usr/sbin. If it is installed in a different location in your environment, then specify the same here.

• This test runs the rndc stats command of to pull metrics of interest from the target BIND DNS server. This command instructs BIND to dump the statistics to a statistics-file configured in the configuration file for the named server - /etc/named.conf. To enable this test to read from this statistics-file, specify the full path to the statistics-file against PATH OF RNDC OUTPUT FILE parameter. By default, metrics are written to the named_stats.txt file in the /var/named/data/ folder. If chroot is enabled, then this file will typically be available in the /var/named/chroot/var/named/data folder.

• To run this test and report metrics, the eG agent install user should have permissions to run the rndc stats command and read from the statistics-file. If the eG agent install user possesses these privileges, then set the USE SUDO flag to No. If the eG agent install user does not have the required permissions, then do the following:

  • Edit the sudoers file on the target host and append an entry of the following format to it:

    <eG_agent_install_user>; ALL=(ALL) NOPASSWD:<Command>;

    For instance, if the eG agent install user is eguser, then the entry in the sudoers file should be:

    eguser ALL=(ALL) NOPASSWD: rndc stats

  • Then, save the file.

  • Finally, set the USE SUDO parameter to Yes.

• If multiple components of the same component type are awaiting configuration, then an APPLY TO OTHER COMPONENTS check box will appear in this page. Clicking on this check box will allow you to apply the configuration to all/selected components of that type.

• Once the necessary values have been provided, clicking on the UPDATE button will register the changes made.

When changing the configuration for specific servers, a “*” beside the text box corresponding to the parameter signifies that these values have to be manually configured by the user. The parameter values that require to be configured will typically be prefixed with a “$” or contain a series of “*”. A value of “none” in the parameter value indicates that the corresponding parameter value can be changed if required.