Hi all, Im interested on using the resource manager with G1 garbage collector. To check if it is possible, I have been reading documentation about heap memory management and I came up with some questions because there are some points in the documentation where it is not clear for me if they are describing requirements or recommendations.
As far as I understood, the requirements for using the Resource Manager are only two: * set the critical heap percentage * configure your GC properly in order to work before the eviction procedure starts. Am I right? There are three points in the documentation that makes me question if I'm correct: 1. The first chapter in https://geode.apache.org/docs/guide/19/managing/heap_use/heap_management.html states how to configure your GC for improving performance, but it only talks about CMS, there is no info about other GCs. 2. In the steps of how to configure ResourceManager, when talking about tuning GC parameters, it talks again only about CMS. 3. In the documentation of ResourceManager class, setCriticalHeapPercentage method, it is stated the following: Many virtual machine implementations have additional VM switches to control the behavior of the garbage collector. We suggest that you investigate tuning the garbage collector when using this type of eviction controller. A collector that frequently collects is needed to keep our heap usage up to date. In particular, on the Sun HotSpot VM, the -XX:+UseConcMarkSweepGC flag needs to be set, [...] So it seems that CMS is a requirement, but I have not found in the code any limitation about using only CMS. If my previous statement about the requirements is fine, then I suppose the documentation needs a review to distinguish between generic requirements and the CMS specific use case. Other question that come to my mind is about the lack of info about G1. As CMS is deprecated since Java 9, are there any plans to test and document G1 configuration? Thanks in advance for your comments! Alberto B.
