[HDFS-14732] [FGL] Introduce PartitionedGSet a new implementation of GSet.

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: namenode
• Assignee: Unassigned
• Reporter: Konstantin Shvachko
• Created: 14/Aug/19 22:31
• Updated: 14/Aug/19 22:31

Description

INodeMap and BlocksMap are currently represented by a hash table implemented as LightWeightGSet. For fine-grained locking it should be replaced by PartitionedGSet - a new implementation of GSet interface, which partitions INodes into ranges based on a key.
We should target static partitioning into a configurable number of ranges. This should allow avoiding the high level lock for RangeMap. It should not be a compromise on efficiency, because parallelism on a single node is bounded by the number of CPU cores.