Hi All,

An aspect of the way EPrints deals with search requests may be causing us some of these issues.

What is happening:

• Something searches your site
• It extracts all the links from the results page – including the paginated links
• These links are saved, and at some point (weeks/months in the future) will be requested from a network of devices
• Each link contains both the cacheid of the original search, and all the parameters needed to re-run the search

When the paginated links are farmed out to the network of devices (hence the spread of IP addresses), the original EPrints search cache has expired.

Each paginated link then triggers the same original search to be run – with each request making a new cache table.

If the original search _expression_ returned 1000 results, presented with 20 links on each page, the follow-up crawl of those paginated links will cause 50 new individual cache tables.

I’ve documented it here: https://github.com/eprints/eprints3.4/issues/479 .

A quick short-term fix would be to stop EPrints auto-re-running a search if the search contained an old cache id.

This changes the current user experience, but I think would be better than systems becoming unresponsive.

NB the above has been observed using the ‘internal’ search methods (rather than Xapian/ElasticSearch).

Cheers,

John

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Yuri Carrer

 CAB - Centro di Ateneo per le Biblioteche, Università di Padova

 Tel: 049/827 9712 - Via Beato Pellegrino, 28 - Padova