[Yazlist] Error Messages

Larry E. Dixson ldix at loc.gov
Thu Jun 5 15:45:35 CEST 2003


Joseph,
I used your script today to perform about about 20 searches between 9:00am
and 9:30am.

I was not able to locate your address in our transaction logs for the last
few days, but I know that we are _not_ blocking your address.  That's not
a factor.

There was some systems maintenance being performed last night when you
attempted to connect using BookWhere.

See if things are behaving better today.
Feel free to contact me directly if you have additional questions.
Larry


On Wed, 4 Jun 2003, Joseph Gruber wrote:

> Larry thanks for the response!
> 
> >> Do you happen to know the IP address of your Z-client?  (That may be
> >> difficult if you are going through an Internet Service Provider.)
> 
> Yup I do.  I'm running a development server before this code goes live & it
> is working off of that.  The domain is josephgruber.com & the IP is
> 67.9.31.7  The script if you want to look at it can be viewed at
> http://www.josephgruber.com/dp-devel/beta/index.php
>  
> >> The "connection failed" message may indicate that our server is currently
> >> at 250 simultaneous users (our maximum).  We moved our Z39.50 server to
> >> another machine last weekend and the environment has not completely
> >> settled yet.  Yesterday from 9:45am until 1:15pm (Eastern US Time) we
> were
> >> at maximum usage until we reinstated a script that looks for and removes
> >> inactive sessions (at least 10 minutes of inactivity).
> >> 
> >> Adam mentioned the long waits from TCP/IP connection through
> >> initResponse.  Adam is correct that these initialization waits are longer
> >> during our peak search period -- i.e., 9:00am - 4:00pm (Eastern US Time,
> >> Monday - Friday).  I'm surprised to learn that those waits reach 80
> >> seconds, however.  I normally don't see waits of that length even when I
> >> use fill-in search forms hosted by Gateways at other locations (e.g., the
> >> ZAP and PHP/YAZ pages on the Index Data Web site).  Sorry for the
> >> difficulties this is causing you.
> >> 
> >> However, Joseph, from your message it sounds like you were getting
> >> sessions started but then suspected that we were blocking your
> >> address.  That's a possibility if we consider the behavior of your client
> >> abusive.  (That's why I asked for your IP address.)  If you 
> >> have developed a batch search facility, please make it emulate a human 
> >> searcher and put a significant pause (e.g., 10 seconds) between searches.
> Some 
> >> batch-search facilities are hitting our server with up to 6 or 7 searches
> per
> >> second.  They are a resource problem for us.
> 
> The reason I thought this was I would be able to run 4 or 5 searches without
> a problem while I was testing a new addition to the code.  However after
> about 5 or 6 it would start coming back with the Timeout & Connect Failed
> messages.  I just assumed I was being "rate-limited".  The script is going
> to be used probably no more than 10-20 times a day and nothing near a batch
> search facility may but I was just worried about these messages coming up
> when the code goes live.  I wanted to make sure I wasn't doing something
> wrong.  Unfortunately our organization doesn't have 30,000 dollars to
> purchase a subscription to some of those pay per search servers. :(  I can
> definatelly understand the 6 or 7 searches a second being an excessive
> amount & uncalled for but the searches I'm having the problem with is about
> 6 or 7 searches in a 5 minute period.
> 
> >From what I've gotten so far on private replies it just seems that I'm
> hitting the server during a peak period, except for yesterday which you
> explained already.  I thank everyone for the great info!
> 
> Joseph
> 
> >> On Wed, 4 Jun 2003, Adam Dickmeiss wrote:
> >> 
> >> > On Wed, Jun 04, 2003 at 09:49:19AM -0400, Joseph Gruber wrote:
> >> > > Ever since I've started using PHP/YAZ to start writing 
> >> some code to interact
> >> > > with the LOC's Z39.50 server so I could pull MARC 
> >> information from them I've
> >> > > always gotten error messages such as "Connect Failed" & 
> >> "Timeout".  These
> >> > > seemed to be a pattern where after a few searches it 
> >> seemed as if the LOC
> >> > > blocked me from connecting for a little while.  Starting 
> >> yesterday I am now
> >> > > getting these messages non-stop.
> >> > > 
> >> > > The "Connect Failed" & "Timeout" messages I get are they 
> >> due to what I think
> >> > > where the server is overloaded or down?  Or that I've 
> >> been temporarily
> >> > > blocked from connecting?  Or could I possibly be doing 
> >> something wrong with
> >> > > my code?  If it's not my code is this something that 
> >> normally happens with
> >> > > the LOC server?
> >> > > 
> >> > > Thanks for any info anyone can provide.
> >> > > Joseph
> >> >
> >> > We've seen this behavior for years, really. Especially after
> >> > 3 PM Western European time. This what I just did:
> >> > adam at gamma:~/proj/yaz/client$ ./yaz-client 
> >> z3950.loc.gov:7090/voyager
> >> > Connecting...OK.
> >> > Sent initrequest.
> >> > Connection accepted by v3 target.
> >> > ID     : 34
> >> > Name   : Voyager LMS - Z39.50 Server
> >> > Version: 1.13
> >> > Options: search present
> >> > Elapsed: 80.771780
> >> > 
> >> > Yes, that's 80 seconds for init.
> >> > 
> >> > -- Adam
> >> > 
> >> > -- 
> >> > Adam Dickmeiss  mailto:adam at indexdata.dk  http://www.indexdata.dk
> >> > Index Data      T: +45 33410100           Mob.: 212 212 66
> >> 
> >> 
> >> ------------------------------------------------------------
> >> Larry E. Dixson                    Internet:    ldix at loc.gov
> >> Network Development and MARC
> >>    Standards Office, LM639
> >> Library of Congress                Telephone: (202) 707-5807
> >> Washington, D.C.  20540-4402       Fax:       (202) 707-0115
> >> 
> >> 
> >> _______________________________________________
> >> Yazlist mailing list
> >> Yazlist at indexdata.dk
> >> http://www.indexdata.dk/mailman/listinfo/yazlist
> >> 
> 





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