Database Reference
In-Depth Information
A reload of configuration files with
lsnrctl
reload
completes successfully, in spite of name
resolution failures, which are logged in the following format:
[13-JUL-2007 00:11:53:427] snlinGetAddrInfo: Name resolution failed for
wrong.host.name
No reverse address translation is performed on IP addresses. Thus, IP addresses that cannot
be translated to host names do not prevent the operation of valid node checking. The operating
system utility
nslookup
may be used to translate between Domain Name Service (DNS) host
names and IP addresses and vice versa. Keep in mind that
nslookup
does not read the hosts file
(
/etc/hosts
on UNIX,
%SYSTEM_ROOT%\system32\drivers\etc\hosts
on Windows, where
SYSTEM_
ROOT
is usually
C:\WINDOWS
). So the TNS Listener may be able to resolve a name or IP address by
calling C programming language library routines (
gethostbyaddr()
,
gethostbyname()
), while
nslookup
may not.
I ran some tests to find out what the undocumented maximum accepted length for the
invited and excluded node lists is. The maximum line length of the Vi editor I used was 2048 bytes.
2
Both parameters were still working fine at this line length. Assuming an average length of 30
bytes for a host name, this length would provide enough room for around 65 entries. If IP addresses
were used, at least 128 IP addresses would fit. The list of valid nodes cannot exceed a single line,
otherwise the error “TNS-00583: Valid node checking: unable to parse configuration parameters”
is signaled and the TNS Listener does not start.
2.
Other editors allow lines that are longer than 2048 bytes. Vim (Vi improved) is an enhanced implemen-
tation of Vi, which supports a line length of more than 2048 bytes. It is available for free at the URL
http://www.vim.org
an
d runs on UNIX, Windows, and Mac OS.
