The RPC handlers monitoring will displayed in the Web UI when the cluster has just started. As time goes on, RPC handlers disappeared .
We have the RPC handlers listed as tasks and stored in CircularFifoBuffer.
CircularFifoBuffer is a first in first out buffer with a fixed size that replaces its oldest element if full.
When we refresh the page, completed tasks will be removed from CircularFifoBuffer.
Not refresh the page for a long time, the oldest element (RPC handlers) will be replaced by new tasks.