Bug 30949 - Error 500 in z3950_search.pl
Summary: Error 500 in z3950_search.pl
Status: NEW
Alias: None
Product: Koha
Classification: Unclassified
Component: Cataloging (show other bugs)
Version: Main
Hardware: All All
: P3 normal
Assignee: Bugs List
QA Contact: Testopia
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-06-12 19:47 UTC by Manos PETRIDIS
Modified: 2023-04-21 18:28 UTC (History)
2 users (show)

See Also:
Change sponsored?: ---
Patch complexity: ---
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Attachments
koha intranet error (6.48 KB, text/plain)
2022-06-12 19:47 UTC, Manos PETRIDIS
Details
Apache error log (4.66 KB, text/plain)
2022-06-12 19:48 UTC, Manos PETRIDIS
Details
Sample Z39.50 settings (25.09 KB, image/png)
2022-06-12 19:54 UTC, Manos PETRIDIS
Details

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Description Manos PETRIDIS 2022-06-12 19:47:55 UTC
Created attachment 135974 [details]
koha intranet error

I wonder how may one debug errors 500 in z3950_search.pl, especially when searching against multiple targets. 

Searching for ISSN 1061-2688 in the following targets (among many others)

host: webcat.lib.unc.edu
port: 210
DB: innopac

host: afton.lib.unc.edu
port: 210
DB: INNOPAC

I get the following error:

Home  Error 500
An error has occurred!
Error 500
This message may have been caused by any of the following reasons:
You made use of an external link to an item that is no longer available
You followed an outdated link e.g. from a search engine or a bookmark
You tried to access a page that needs authentication
An internal link in the client is broken and the page does not exist
What's next?
Use top menu bar to navigate to another part of Koha.
To report a broken link or any other issue, please contact the Koha administrator. Send email

Error logs to be uploaded. Please don't focus on the server mentioned in them, as I located the servers above in previous tries but decided to file a bug report on subsequent searches that produced said error. 

In different previous searches I've encountered the same problem while searching against targets

host: NLS.ALMA.EXLIBRISGROUP.COM 
port: 210 
DB: 44NLS_INST
(https://www.nls.uk/catalogues/z39-50/)

host: ELIBRARY.MEL.ORG
port: 210 
DB: INNOPAC

for example. Again, these are merely the targets I had managed to narrow down in the past. 

I noticed that tag 915 is mentioned in the logs (...Field 915 must have at least one subfield...), whereas no such tag is defined in standard koha frameworks such as BKS and SER. Could this be the culprit, data that koha doesn't expect to receive? Those very targets work fine when queried for different books/magazines, so it must be something contained in specific results.

The error may also have to do with the fact that all Z39.50 servers defined in my installation have "Del952.xsl,Del9LinksExcept952.xsl" in the "XSLT File(s) for transforming results" field. Both XSLT files are stock, as provided in a packages installation.

Some 10 years ago I had made the same question, but got nowhere.
https://lists.katipo.co.nz/public/koha/2012-August/033847.html
Comment 1 Manos PETRIDIS 2022-06-12 19:48:35 UTC
Created attachment 135975 [details]
Apache error log
Comment 2 Manos PETRIDIS 2022-06-12 19:54:00 UTC
Created attachment 135976 [details]
Sample Z39.50 settings
Comment 3 Esther Melander 2023-04-21 18:28:22 UTC
This problem recently appeared for for our library.

To reproduce:
1. Set up Seattle Public Library as a search target
Host:	zserver.spl.org
Port:	210
DN:	horizon

2. Edit a bibliographic record in the advanced editor and then click on Advanced Search to search for a new record to overlay the original. Be sure to have Seattle Public Library selected as a search target as well as Library of Congress.

3. Perform the search using an ISBN search.

Search results should be returned from Library of Congress.

4. Repeat the search but do a title search instead.

No search results are returned and instead the Error 500 pops up.

Repeat the above searches with the z3950 search in the basic editor. No Error 500 occurs with either an ISBN search or a title search.

After some investigation it appears that Seattle has migrated to a new platform and their z3950 protocol no longer works. 

It seems that in the cases where there was no server error, the z3950 search ignored or skipped the lack of response from Seattle whereas the advanced search in the advanced editor created a stop when there was no response. We would not have known about the problem without the server error, so in that sense it was helpful in at least alerting us to a problem.

It may be helpful to change the Error 500 response message to something that makes it clear there is no response from a search target. There should be consistent behavior across all z3950 searches in the system. It would also be nice to have a test tool in the z3950 setup to be able to test the targets periodically.