ZGC large-heap Java garbage collector may go open source

Posted on 27-10-2017 , by: admin , in , 0 Comments

An Oracle-developed, low-latency Java garbage collector geared to large heaps could move to the open source community, if a proposal to do so gets community approval. Votes are due by November 8.

Called the Z Garbage Collector (ZGC), the project is designed to support multiterabyte heaps, have pause times not exceeding 10 milliseconds, and offer no more than a 15 percent application reduction throughput compared to the G1 garbage collector.

But ZGC’s developers don’t see these goals as “hard requirements” for every workload, according to a proposal floated on an OpenJDK mailing list by Per Liden, a member of the HotSpot virtual machine team at Oracle. Liden’s proposal calls for creation of a ZGC project that he would lead, with the HotSpot group as sponsor. 

With ZGC, operations such as object loading can be done concurrently while application threads are running. ZGC executes tasks including marking, reference processing, and relocation/compaction. Remaining tasks, including class unloading and weak root processing, are made concurrent.