Geonetwork hangs after a weekend

Hi, im running geonetwork 4.2.3 in a tomcat 9.0 with java 1.8, elasticsearch 7.something (the highest version that still supports java 8).

The issue at hand is that after a weekend, on the very first request to geonetwork, it hangs, doesnt load for like 15 minutes, however, if you open a second tab and request geonetwork again, it loads, perfectly without any issue,

i attached a profiler to check what was happening, ram was spiking and being GC quite quickly, cpu didnt really spike past 10% while this was happening and the only threads that were putting CPU time were the ones listening and catalina's utility.

im a bit lost here, is there a way to avoid this cold start apart from making a script that calls geonetwork every 2 hours or so.

Thanks.

Start by reproducing the first-request delay after a weekend or comparable idle period in GeoNetwork 4.2.3 with Tomcat 9.0, Java 1.8, and Elasticsearch 7.x. Use the profiler observations to trace the first request and compare it with a second request; done means identifying the cause of the cold-start hang and documenting or testing a fix that removes the long delay.

Written by the indexing model from the issue text.