Probing Linux DNS server health

In a Linux environment, a widely popular bind server is provided, which is the most common server software for building DNS servers. Introduction to the installation of bind now a lot of articles, now we will talk about the maintenance of the topic. How can we understand the operation of the DNS server, it is not busy, the load is not large? All of this, for system administrators, is more important.

To understand the health of the DNS server, you can do so by looking at the log files generated by the DNS server at run time.

BIND 8 provides some means of controlling the logging system, but the default state generates enough logs to understand the current health of the DNS server.

By default, Bind generates logs from Syslog and is stored in/var/log/message files. Note: The following four documents are also relevant:

/var/log/message.1

/var/log/message.2

/var/log/message.3

/var/log/message.4

In fact, the log is divided into 5 files to store, to prevent the file is too large, when the message file large enough, it became a message.1, the original message.1 became MESSAGE.2......,MESSAGE.4 content disappeared.

Because the log information in this file is generated by syslog, it is not and is all about bind log information. We select the log information for all bind by executing the following command:

More/var/log/message|grep named >/tmp/named.log

Note: The process name of the BIND server is named.

In this way, the log information associated with BIND in/var/log/message is written to the/tmp/named.log file. The main log has two kinds: the log_notice,log_info level of the log.

First, Log_notice level log

1. Each time you start the BIND server named, a Log_notice-level log message is generated that looks like this:

Nov 10:37:45 www named[10134]: Starting. Named 8.2.2-p3

which