安装Oracle 11g RAC R2 之Linux DNS 配置
安装Oracle 11g RAC R2 之Linux DNS 配置
Oracle 11g RAC 集群中引入了SCAN(Single Client Access Name)的概念，也就是指集群的单客户端访问名称。SCAN 这个特性为客户端提供了单一的主机名，用于访问集群中运行的 Oracle 数据库。如果您在集群中添加或删除节点，使用 SCAN 的客户端无需更改自己的 TNS 配置。无论集群包含哪些节点，SCAN 资源及其关联的 IP 地址提供了一个稳定的名称供客户端进行连接使用。在Oracle 11g grid 安装时即要求为该特性配置DNS解析方式或GNS解析方式。本文描述了安装Oracle 11g grid时的DNS配置。
1、安装环境
#配置DNS，可以使用单独的DNS服务器，也可以直接使用RAC的一个节点来提供DNS解析
#直接使用某个节点时，容易出现该节点如果宕机将导致SCAN无法解析，客户端无法连接数据库
#本文仅作演示，使用节点1的public ip用作dns，不考虑上面描述的情形以及DNS安全性等。
[root@node1 ~]# cat /etc/issue
Enterprise Linux Enterprise Linux Server release 5.5 (Carthage)
Kernel \r on an \m
2、主机节点host信息
[root@node1 ~]# more /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
#127.0.0.1 localhost.localdomain localhost
#::1 localhost6.localdomain6 localhost6
127.0.0.1 localhost.szdb.com localhost
# Public eth0
192.168.7.71 node1.szdb.com node1 #该地址作为DNS服务器地址
192.168.7.72 node2.szdb.com node2
#Private eth1
10.10.7.71 node1-priv.szdb.com node1-priv
10.10.7.72 node2-priv.szdb.com node2-priv
#Virtual
192.168.7.81 node1-vip.szdb.com node1-vip
192.168.7.82 node2-vip.szdb.com node2-vip
#scan
192.168.7.91 scan-cluster1.szdb.com scan-cluster1
3、配置dns需要用到的安装包
[root@node1 dns_rpm]# ls -hltr
total 1.1M
-rw-r--r-- 1 root root 45K Dec 7 18:04 bind-chroot-9.3.6-4.P1.el5_4.2.i386.rpm
-rw-r--r-- 1 root root 985K Dec 7 18:04 bind-9.3.6-4.P1.el5_4.2.i386.rpm
-rw-r--r-- 1 root root 61K Dec 7 18:04 caching-nameserver-9.3.6-4.P1.el5_4.2.i386.rpm
#下面安装rpm包
[root@node1 dns_rpm]# rpm -Uvh bind-9.3.6-4.P1.el5_4.2.i386.rpm
warning: bind-9.3.6-4.P1.el5_4.2.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing... ########################################### [100%]
1:bind ########################################### [100%]
[root@node1 dns_rpm]# rpm -Uvh bind-chroot-9.3.6-4.P1.el5_4.2.i386.rpm
warning: bind-chroot-9.3.6-4.P1.el5_4.2.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing... ########################################### [100%]
1:bind-chroot ########################################### [100%]
[root@node1 dns_rpm]# rpm -Uvh caching-nameserver-9.3.6-4.P1.el5_4.2.i386.rpm
warning: caching-nameserver-9.3.6-4.P1.el5_4.2.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing... ########################################### [100%]
1:caching-nameserver ########################################### [100%]
4、配置DNS
#关于DNS的配置，分为以下几个步骤
#a.安装所需的rpm包
#b.配置named.conf文件
#c.配置zone文件，包括正向和反向zone文件
#d.配置解析文件resolv.conf
#e.启动dns服务
[root@node1 ~]# cd /var/named/chroot/etc/
#使用下面的方式复制两个新的副本并修改，参数-p表示连同权限及属主，属组一同复制。切记不可忽略参数-p
[root@node1 etc]# cp -p named.caching-nameserver.conf named.conf
[root@node1 etc]# cp -p named.rfc1912.zones named.zones
#修改named.conf文件，将源文件中的所有localhost以及127.0.0.1修改成any，注意any;前后保留空格
#该文件主要是配置dns监听那些端口以及ip地址并指明相应的名字解析zone文件名named.zones
#下面是修改后的named.conf文件
[root@node1 ~]# cat /var/named/chroot/etc/named.conf
//
// named.caching-nameserver.conf
//
// Provided by Red Hat caching-nameserver package to configure the
// ISC BIND named(8) DNS server as a caching only nameserver
// (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
// DO NOT EDIT THIS FILE - use system-config-bind or an editor
// to create named.conf - edits to this file will be lost on
// caching-nameserver package upgrade.
//
options {
listen-on port 53 { any; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
// Those options should be used carefully because they disable port
// randomization
// query-source port 53;
// query-source-v6 port 53;
allow-query { any; };
allow-query-cache { any; };
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
view localhost_resolver {
match-clients { any; };
match-destinations { any; };
recursion yes;
include "/etc/named.zones";
};
#修改named.zones文件，该文件用于指定zone的搜索范围，包括正向和反向。文件末尾最后的两个zone为新增加的
#注意每一个zone的file用于指向真正的zone文件，后面要用到
# Author : Robinson
# Blog : http://blog.csdn.net/robinson_0612
#下面是修改后的named.zones文件
[root@node1 ~]# cat /var/named/chroot/etc/named.zones
// named.rfc1912.zones:
//
// Provided by Red Hat caching-nameserver package
//
// ISC BIND named zone configuration for zones recommended by
// RFC 1912 section 4.1 : localhost TLDs and address zones
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
zone "." IN {
type hint;
file "named.ca";
};
zone "localdomain" IN {
type master;
file "localdomain.zone";
allow-update { none; };
};
zone "localhost" IN {
type master;
file "localhost.zone";
allow-update { none; };
};
zone "0.0.127.in-addr.arpa" IN {
type master;
file "named.local";
allow-update { none; };
};
zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
type master;
file "named.ip6.local";
allow-update { none; };
};
zone "255.in-addr.arpa" IN {
type master;
file "named.broadcast";
allow-update { none; };
};
zone "0.in-addr.arpa" IN {
type master;
file "named.zero";
allow-update { none; };
};
#Add new zone added by Robinson
#以下两个zone为新增的，包含正向和反向zone
zone "szdb.com" IN {
type master;
file "node1.szdb.zero";
allow-update { none; };
};
zone "7.168.192.in-addr.arpa" IN {
type master;
file "7.168.192.local";
allow-update { none; };
};
#配置正向和反向搜索数据库解析文件
[root@node1 etc]# pwd
/var/named/chroot/etc
[root@node1 etc]# cd ../var/named/
#同样使用cp -p 方式复制文件到新的正向和反向文件
[root@node1 named]# cp -p named.zero node1.szdb.zero
[root@node1 named]# cp -p named.local 7.168.192.local
#下面是修改之后的正向搜索文件，���可以将host文件的其他ip对照编辑到正向搜索文件以实现解析
#如下面的例子将vip的参照关系也添加到解析文件
[root@node1 named]# cat node1.szdb.zero
$TTL 86400
@ IN SOA node1.szdb.com. root.szdb.com. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS node1.szdb.com.
scan-cluster1 IN A 192.168.7.91
scan-cluster1 IN A 192.168.7.92
scan-cluster1.szdb.com IN A 192.168.7.91
scan-cluster1.szdb.com IN A 192.168.7.92
node1-vip IN A 192.168.7.81
node2-vip IN A 192.168.7.82
node1-vip.szdb.com IN A 192.168.7.81
node2-vip.szdb.com IN A 192.168.7.82
#下面是修改之后的反向搜索文件
[root@node1 named]# cat 7.168.192.local
$TTL 86400
@ IN SOA node1.szdb.com. root.szdb.com. (
1997022700 ; Serial
28800 ; Refresh
14400 ; Retry
3600000 ; Expire
86400 ) ; Minimum
IN NS node1.szdb.com.
1 IN PTR node1.szdb.com.
91 IN PTR scan-cluster1.szdb.com.
92 IN PTR scan-cluster1.szdb.com.
91 IN PTR scan-cluster1.
92 IN PTR scan-cluster1.
81 IN PTR node1-vip.
82 IN PTR node2-vip.
81 IN PTR node1-vip.szdb.com.
82 IN PTR node2-vip.szdb.com.
#在各个节点配置resolv.conf文件
#下面是修改之后的内容
[root@node1 named]# more /etc/resolv.conf
; generated by /sbin/dhclient-script
#the following item removed by Robinson
#search SSG-140
#nameserver 192.168.7.10
#nameserver 192.168.7.11
#the following item added by Robinson
search szdb.com
nameserver 192.168.7.71
#节点2上的resolv.conf文件
[root@node2 ~]# more /etc/resolv.conf
; generated by /sbin/dhclient-script
#search SSG-140
#nameserver 192.168.7.10
#nameserver 192.168.7.11
search szdb.com
nameserver 192.168.7.71
#启动dns服务
[root@node1 named]# service named restart
Stopping named: [ OK ]
Starting named: [ OK ]
[root@node1 named]# chkconfig named on
#测试dns解析
[root@node1 named]# cd ~
[root@node1 ~]# nslookup 192.168.7.91
Server: 192.168.7.71
Address: 192.168.7.71#53
91.7.168.192.in-addr.arpa name = scan-cluster1.
91.7.168.192.in-addr.arpa name = scan-cluster1.szdb.com.
[root@node1 ~]# nslookup 192.168.7.92
Server: 192.168.7.71
Address: 192.168.7.71#53
92.7.168.192.in-addr.arpa name = scan-cluster1.szdb.com.
92.7.168.192.in-addr.arpa name = scan-cluster1.
[root@node1 ~]# nslookup scan-cluster1
Server: 192.168.7.71
Address: 192.168.7.71#53
Name: scan-cluster1.szdb.com
Address: 192.168.7.92
Name: scan-cluster1.szdb.com
Address: 192.168.7.91
[root@node1 ~]# nslookup scan-cluster1.szdb.com.
Server: 192.168.7.71
Address: 192.168.7.71#53
Name: scan-cluster1.szdb.com
Address: 192.168.7.91
Name: scan-cluster1.szdb.com
Address: 192.168.7.92
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