Contao search indexing issue

We've had some issues with some pages on our sites timing out and generally taking too long to load.

We noticed that on one of the sites the tl_search_index table had reached 2,354,0751 records at a size of 1.2GB. We cleared the search index and disabled indexing under the CMS settings and the loading issues were instantly cured.

After looking into it more we discovered that the tl_search_index table was rapidly being filled up as we clicked around the site. After clearing the search index then clicking on a couple of pages about 3000 records had been added to the table. We believe this is the cause of the slow load times we were seeing.

As well as this the tl_search table contained 69621 records at 900mb.

This site was running on Contao 2.11.8, but we've also seen the same issue on another site running 2.11.3.

Has any one else seen this issue? Does anyone know how the indexing works and should if it be causing such a high load on the server?

Cheers,
Jamie

Are there any filter/sort options that influence on the URL parameters? In the past, I noticed that the search index has become constantly greater and greater when there was e.g. a Catalog filter/sort module. That is, the same keywords were stored multiple times in the search index.

Hi,

yes this site does have some dynamic pages that makes use of URL parameters. Maybe that explains the high number of records in the index table.

I'm not sure why this would cause the whole site to slow down though, even when visiting a page (without url parameters) for the second time as surely the page would have been indexed the first time. Unless it was just the size of the table slowing things down.

Anyway, now we've disabled indexing the site is running better than it ever has. I didn't realise the impact that the indexing had on the load times until now.