This system is not registered with ULN

[root@DBDATA yum.repos.d]# yum makecache
Loaded plugins: aliases, changelog, downloadonly, fastestmirror, filter-data, keys, kmod, list-data, priorities, protect-packages, protectbase, rhnplugin, security, tmprepo, verify,
: versionlock
This system is not registered with ULN.
You can use up2date --register to register.
ULN support will be disabled.
Determining fastest mirrors
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
http://mirrors.aliyun.com/centos/5Server/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirrors.aliyuncs.com/centos/5Server/os/x86_64/repodata/repomd.xml: [Errno 12] Timeout: <urlopen error timed out>
Trying other mirror.
http://mirrors.cloud.aliyuncs.com/centos/5Server/os/x86_64/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again

[root@DBDATA ~]# cat /etc/issue
Oracle Linux Server release 5.11
Kernel \r on an \m

[root@DBDATA ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5.11 (Tikanga)
[root@DBDATA ~]#
[root@DBDATA yum.repos.d]# wget http://public-yum.oracle.com/public-yum-el5.repo
--2019-11-14 16:31:13-- http://public-yum.oracle.com/public-yum-el5.repo
Resolving public-yum.oracle.com... 23.51.208.176
Connecting to public-yum.oracle.com|23.51.208.176|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 4886 (4.8K) [text/plain]
Saving to: `public-yum-el5.repo'

100%[============================================================================================================================================>] 4,886 --.-K/s in 0s

2019-11-14 16:31:15 (129 MB/s) - `public-yum-el5.repo' saved [4886/4886]

[root@DBDATA ~]# cd /etc/yum.repos.d
[root@DBDATA yum.repos.d]# yum clean all
Loaded plugins: aliases, changelog, downloadonly, fastestmirror, filter-data, keys, kmod, list-data, priorities, protect-packages, protectbase, rhnplugin, security, tmprepo, verify,
: versionlock
Cleaning up Everything
Cleaning up list of fastest mirrors
[root@DBDATA yum.repos.d]# yum makecache
Loaded plugins: aliases, changelog, downloadonly, fastestmirror, filter-data, keys, kmod, list-data, priorities, protect-packages, protectbase, rhnplugin, security, tmprepo, verify,
: versionlock
This system is not registered with ULN.
You can use up2date --register to register.
ULN support will be disabled.
Determining fastest mirrors
el5_latest | 1.4 kB 00:00
el5_latest/filelists | 46 MB 04:56
el5_latest/updateinfo | 832 kB 00:05
el5_latest/other | 284 MB 30:50
el5_latest/group | 1.1 MB 00:12
el5_latest/primary | 29 MB 03:40
ol5_UEK_latest | 1.2 kB 00:00
ol5_UEK_latest/filelists | 21 MB 03:16
ol5_UEK_latest/updateinfo | 134 kB 00:00
ol5_UEK_latest/other | 111 MB 10:08
ol5_UEK_latest/primary | 32 MB 02:20
el5_latest 15734/15734
ol5_UEK_latest 686/686
el5_latest 15734/15734
ol5_UEK_latest 686/686
el5_latest 15734/15734
ol5_UEK_latest 686/686
Metadata Cache Created