JANUS NAMESERVER - Revision history

Dme at 14:32, 3 July 2013

2013-07-03T14:32:15Z

← Older revision		Revision as of 14:32, 3 July 2013
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	This specifies the IP address(es) and port(s) of the TCP/IP name server(s).		This specifies the IP address(es) and port(s) of the TCP/IP name server(s).

	The <var>JANUS NAMESERVER</var> command only has an effect when running in an IBM (<code>TCPTYPE=IBM</code>) TCP/IP environment. ~~If <var>JANUS NAMESERVER</var> is executed without parameters, it displays the current setting for <var>NAMESERVER</var>.~~		If <var>JANUS NAMESERVER</var> is executed without parameters, it displays the current setting for <var>NAMESERVER</var>.

			The <var>JANUS NAMESERVER</var> command only has an effect when running in an IBM (<code>TCPTYPE=IBM</code>) TCP/IP environment.


	==Syntax==		==Syntax==

			The following form, invoked without any parameters, displays the current <var>NAMESERVER</var> setting:
			<p class="syntax"> JANUS NAMESERVER</p>

			The following form specifies the new <var>NAMESERVER</var> setting:
	<p class="syntax"> JANUS NAMESERVER ip_address port_number -		<p class="syntax"> JANUS NAMESERVER ip_address port_number -
	[AND ip_address port_number]] ... -		[AND ip_address port_number]] ... -

JALWiccan: Automatically generated page update

2013-04-16T17:32:04Z

Automatically generated page update

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	{{DISPLAYTITLE:JANUS NAMESERVER}}		{{DISPLAYTITLE:JANUS NAMESERVER}}
	<span class="pageSubtitle"~~><section begin="desc" /~~>NAMESERVER~~<section end="desc" />~~</span>		<span class="pageSubtitle">NAMESERVER</span>

	This specifies the IP address(es) and port(s) of the TCP/IP name server(s).		This specifies the IP address(es) and port(s) of the TCP/IP name server(s).
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	==Syntax==		==Syntax==

	<p class="syntax"~~><section begin="syntax" /~~> JANUS NAMESERVER ip_address port_number -		<p class="syntax"> JANUS NAMESERVER ip_address port_number -
	[AND ip_address port_number]] ... -		[AND ip_address port_number]] ... -
	[TIMEOUT numsec] -		[TIMEOUT numsec] -
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	[MAXTTL maxsec] -		[MAXTTL maxsec] -
	[RETRIES num]		[RETRIES num]
	~~<section end="syntax" />~~</p>		</p>

	<table class="syntaxTable">		<table class="syntaxTable">
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	<tr><th><var>CACHE</var> numcache</th>		<tr><th><var>CACHE</var> numcache</th>
	<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">numcache</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage — cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>		<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">numcache</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage — cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>

	<tr><th><var>MAXTTL</var> maxsec</th>		<tr><th><var>MAXTTL</var> maxsec</th>

JAL at 22:17, 30 October 2012

2012-10-30T22:17:13Z

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	</td></tr></table>		</td></tr></table>

	See also		==See also==
	<ul>		<ul>
	<li>[[List of Janus commands]]		<li>[[List of Janus commands]]

JAL: /* Syntax */

2012-10-30T22:16:57Z

Syntax

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	</p>		</p>

	Since name servers rarely go down, it is probably quite unnecessary to have more than two name servers, but as many as eight name servers are supported by Janus.<~~blockquote~~> A negative response from a name server, that is, a response that indicates that the name server does not know the requested host name, does '''not''' cause a subsequent name server to be tried. If name servers are properly configured, changing name servers should not affect the success of a hostname lookup.</~~blockquote~~>		Since name servers rarely go down, it is probably quite unnecessary to have more than two name servers, but as many as eight name servers are supported by Janus.
			<p>
			'''Note:''' A negative response from a name server, that is, a response that indicates that the name server does not know the requested host name, does '''not''' cause a subsequent name server to be tried. If name servers are properly configured, changing name servers should not affect the success of a hostname lookup.</p>

	The other <var>JANUS NAMESERVER</var> command parameters available in <var class="product">Sirius Mods</var> Version 6.8 and later are:		The other <var>JANUS NAMESERVER</var> command parameters available in <var class="product">Sirius Mods</var> Version 6.8 and later are:
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	</td></tr></table>		</td></tr></table>

	See: [[List of Janus commands]]		See also
			<ul>
			<li>[[List of Janus commands]]
			</ul>

	[[Category:Janus commands\|JANUS NAMESERVER]]		[[Category:Janus commands\|JANUS NAMESERVER]]

JALWiccan: 1 revision

2012-10-30T22:02:45Z

1 revision

← Older revision	Revision as of 22:02, 30 October 2012
(No difference)

JAL2 at 22:02, 30 October 2012

2012-10-30T22:02:32Z

← Older revision		Revision as of 22:02, 30 October 2012
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	<tr><th><var>CACHE</var> numcache</th>		<tr><th><var>CACHE</var> numcache</th>
	<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">numcache</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage -- cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>		<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">numcache</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage — cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>

	<tr><th><var>MAXTTL</var> maxsec</th>		<tr><th><var>MAXTTL</var> maxsec</th>

JAL2 at 21:39, 7 August 2012

2012-08-07T21:39:02Z

← Older revision		Revision as of 21:39, 7 August 2012
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	<tr><th><var>CACHE</var> numcache</th>		<tr><th><var>CACHE</var> numcache</th>
	<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">~~Numcache~~</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage -- cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>		<td>This parameter indicates that <var class="product">Janus Sockets</var> is to save hostname-to-IP address mappings in the Online address space. This means that subsequent name server lookups would be extremely fast in-memory lookups, rather than calls to an external name server. This would both save CPU and reduce name lookup latency. <var class="term">numcache</var> is the maximum number of hostnames to cache in the Online. Names are cached in virtual storage, and the amount of virtual storage required for the cache is about 100*<var class="term">numcache</var>. If the number of hostnames ever looked up is relatively small, it would make sense to set <var class="term">numcache</var> to a little more than this number of hostnames. Otherwise, the setting of <var class="term">numcache</var> is a trade-off between CPU savings and latency and virtual storage -- cache entries are saved according to a most-recently-used algorithm so that frequently requested hostnames tend to remain in cache. There are several system statistics the can be viewed via <var class="product">[[SirMon]]</var> that make it possible to determine how well the name caching is working. These statistics are described below.</td></tr>

	<tr><th><var>MAXTTL</var> maxsec</th>		<tr><th><var>MAXTTL</var> maxsec</th>

JALWiccan: 1 revision

2012-06-19T22:07:55Z

1 revision

← Older revision	Revision as of 22:07, 19 June 2012
(No difference)

JAL2 at 22:07, 19 June 2012

2012-06-19T22:07:45Z

← Older revision		Revision as of 22:07, 19 June 2012
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	<tr><th><var>RETRIES</var> num</th>		<tr><th><var>RETRIES</var> num</th>
	<td>This parameter retries a DNS UDP packet for which no response is received. This means that if <var class="product>Janus</var> does a DNS lookup just when the target nameserver is down for an instant, or if the UDP packet gets lost on the network (IP networks don't have to guarantee delivery of IP packets), the DNS lookup does not fail.		<td>This parameter retries a DNS UDP packet for which no response is received. This means that if <var class="product">Janus</var> does a DNS lookup just when the target nameserver is down for an instant, or if the UDP packet gets lost on the network (IP networks don't have to guarantee delivery of IP packets), the DNS lookup does not fail.
	<p>		<p>
	Setting <var>RETRIES</var> to a positive integer value, say 2, instructs <var class="product>Janus</var>		Setting <var>RETRIES</var> to a positive integer value, say 2, instructs <var class="product">Janus</var>
	to retry as many as two times if no response was received to a DNS lookup.		to retry as many as two times if no response was received to a DNS lookup.
	Setting <var>RETRIES</var> to 0, its default, means no retries are attempted.</p>		Setting <var>RETRIES</var> to 0, its default, means no retries are attempted.</p>

JAL2 at 22:49, 18 June 2012

2012-06-18T22:49:22Z

← Older revision		Revision as of 22:49, 18 June 2012
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	It probably does not make sense to set <var>RETRIES</var>		It probably does not make sense to set <var>RETRIES</var>
	to a value greater than 2: if packets are being dropped so frequently		to a value greater than 2: if packets are being dropped so frequently
	that three consecutive DNS requests are dropped, you have problems much more serious than the failed lookups. </p></td></tr>		that three consecutive DNS requests are dropped, you have problems much more serious than the failed lookups. </p>
			<p>
			<var>RETRIES</var> is available as of Version 7.8 of the <var class="product">Sirius Mods</var>. </p></td></tr>
	</table>		</table>