LISTSERV mailing list manager LISTSERV 16.0

Help for ZNG Archives


ZNG Archives

ZNG Archives


ZNG@C4VLPLISTSERV01.LOC.GOV


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Monospaced Font

LISTSERV Archives

LISTSERV Archives

ZNG Home

ZNG Home

ZNG  April 2010

ZNG April 2010

Subject:

Re: Add "reliability" index to CQL's "zeerex" context set

From:

Mike Taylor <[log in to unmask]>

Reply-To:

SRU (Search and Retrieve Via URL) Implementors

Date:

Wed, 14 Apr 2010 11:51:36 +0100

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (104 lines)

Peter, we didn't envisage this as something that servers self-report,
but as something measured from the outside. To a client, it's
irrelevant whether a server is running off a UPS, for example: all we
care about is whether we can contact and search in and retrieve from
the server.

In IRSpy (http://irspy.indexdata.com/) the reliability measurement
simply indicates how often the server responded to connection
requests. It's a trivialised notion of what it means to be
"available", but as is so often the case, 10% of the work gets you 90%
of that functionality, and it's functionality that we need. (I
deliberately proposed a vague semantics statement for availability
because I don't want to enforce that rather dumb definition of
availability on everyone who uses it.)

Similarly, Ed Zimmerman's message hugely over-complicates this simple
concept, and ends up concluding, as such messages so often do, that we
should do nothing. Sorry, Ed, not having that. As a compromise, I am
perfectly happy for _you_ to do nothing :-)



On 14 April 2010 01:18, Peter Noerr <[log in to unmask]> wrote:
> Back to the original suggestion, after the rather ironic detour this thread took...
>
> Such numbers would be useful to us as a fed search service. We actually maintain this sort of data for all the Sources we connect to, by means of an active checking program of our own, so it would not add greatly to our own practices, but it would be useful to have the site's own idea of how often it thought it was available, and it would be useful to the vast majority of systems which had no justification to set up monitoring programs.
>
> Which leads to the question of what this "percentage reliability" is actually measuring and how? The aforementioned power outage and servers playing doorstops obviously counts as "unavailable", but what if they were still happily running on their (long life) UPS, while the router was down? From the outside world's point of view both are bad, but how does the server check itself from outside? And is this a time average, a moving average, a snapshot, based on number of tries irrespective of time, or just whatever the server thinks is a good idea (better than nothing - probably)?
>
> Peter
>
>> -----Original Message-----
>> From: SRU (Search and Retrieve Via URL) Implementors
>> [mailto:[log in to unmask]] On Behalf Of John Harrison
>> Sent: Tuesday, April 13, 2010 7:29 AM
>> To: [log in to unmask]
>> Subject: Re: Add "reliability" index to CQL's "zeerex" context set
>>
>> Hi all
>>
>> These contextSet sites haven't been lost - there was a power cut over
>> the weekend affecting all cheshire3.org servers. Some came back on with
>> the power and some didn't. I've been in the US, but will get round to
>> fixing them tomorrow.
>>
>> Sorry for any inconvenience this has caused.
>>
>> Personally, I think the reliability index sounds like it could be
>> useful
>> so I'll monitor this mailing list for a couple of days to see if there
>> are any other comments, then add it to the ZeeRex context set.
>>
>> All the best,
>>
>> John
>>
>>
>> On Mon, 2010-04-12 at 17:22 +0100, Mike Taylor wrote:
>> > We have found it useful, in our IRSpy register of Z39.50 and SRU
>> > targets, to add a measure of "reliability" for each server, expressed
>> > as a percentage and measuring what proportion of all the connections
>> > we've tried to make have been successful.  Using this, we can search
>> > for only those targets that are up, say, 90% of the time.  (This
>> > searching facility is not yet wired out to the public Web UI at
>> > http://irspy.indexdata.com/ but it will be.)
>> >
>> > In order to enable searching in this way via SRU, we need to add a
>> > "reliability" index -- so far as we can determine, there is no such
>> > index in any of the existing context sets.  This seems like a good
>> > match for ZeeRex, which is all about describing databases and the
>> > services that provide them, so we propose that the new index be added
>> > to the ZeeRex context set.  We propose a brief, non-prescriptive
>> > semantics statement like "an integer in the range 0-100 indicating
>> how
>> > reliable the server had been found to be".
>> >
>> > --
>> >
>> > As an aside, the LC page about context sets,
>> >         http://www.loc.gov/standards/sru/resources/context-sets.html
>> > links the ZeeRex set to the location:
>> >         http://srw.cheshire3.org/contextSets/ZeeRex/
>> > but this URL has gone away since Rob Sanderson left the Cheshire
>> > project.  So have the Record Metadata set ("rec"), the Network
>> > Resource Information set ("net"), the Collectable Card Games set
>> > ("ccg") though that one will probably not cause so many problems, and
>> > the Relevance Ranking set ("rel").  This is very bad.
>> >
>> > Some, but not all, of those sets are available as old versions on the
>> > WayBack Machine: for example, there is an old "rec" set at
>> >
>> http://web.archive.org/web/20060717085701/http://srw.cheshire3.org/cont
>> extSets/net/1.0/
>> > but I have not been able to get it to give me an old "zeerex" set.
>> >
>> > For that reason, I have resurrected an old copy of the ZeeRex site as
>> > it was before I foolishly handed it over to Rob, and it is now
>> > available on
>> >         http://zeerex.z3950.org/
>> > In particular, the ZeeRex context set for CQL is at:
>> >         http://zeerex.z3950.org/search/contextset/2.0/
>> > I hope this is useful to more than just me.
>

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

July 2017
October 2016
July 2016
August 2014
February 2014
December 2013
November 2013
October 2013
February 2013
January 2013
October 2012
August 2012
April 2012
January 2012
October 2011
May 2011
April 2011
November 2010
October 2010
September 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
October 2009
September 2009
August 2009
July 2009
May 2009
April 2009
March 2009
February 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager