Performance issues with larger amounts of data

[krabina]

Setup

Product	Version
MediaWiki	1.35.6
PHP	7.4.3 (fpm-fcgi)
MariaDB	10.3.34-MariaDB-0ubuntu0.20.04.1
ICU	66.1
Elasticsearch	6.8.23
LuaSandbox	4.0.2
Lua	5.1.5
Semantic MediaWiki	4.0.2
Maps	9.0.7

Issue

This rather simple query displays an error:

Unstrip size limit exceeded (5,000,000)

{{#ask:[[Category:Correspondence]]
 |mainlabel=Institution
 |?Coordinates
 |?Author
 |?Language
 |format=map
 |limit=5000
}}

If I try to remove some printouts, to make it smaller, sometimes the message does not get displayed, but only a blank page is showing.

So the first improvement would be to fetch the problem to avoid the error and especially a blank page.

https://fina.knowledge.wiki/Test_Map

Performance

But the more general question is how to make maps that show several thousands of entries. With markerclusters, this is not a visulazation problem any more.

• Maybe with the deferred marker?
• Or with some kind of pre-clustering?
• Or with a better working ajax reload (see strange behaviour of ajaxqueries with large datasets #649)

See also #565

[JeroenDeDauw]

Presumably what you are running into here is some MediaWiki page-size limit. All the data for the markers is stored in the page, so clustering has zero impact on the amount. If you are indeed running into the page-size limit, then the way around that is dynamic loading of data such as via the "ajaxqueries". Though one can imagine a new mechanism where the whole data set is still loaded on page load, but just is not cached within the page content.