Yes 18% of total physical RAM. The failures in G1GC and CMS setup did seem to be from pause the world.
We are using Solr Docker image which is using G1GC by default and we tuned with G1GC. Even with tuning the performance test failed after about 8 hours. With ZGC we had consistent 12 and 24 hour performance test which ran flawlessly. We are running another 24 hour test with 8GB JVM and so far it is also running flawlessly. I will post an update when completed. Garbage collection is not my area of expertise but so far I am following the data and out of the box ZGC is performing drastically better. -- Sent from: https://lucene.472066.n3.nabble.com/Solr-User-f472068.html
