Signed-off-by: Gyuho Lee <leegyuho@amazon.com>
advance() should use rs.req.Entries[0].Data as the context instead of req.Context for deletion. Since req.Context is never set, there won't be any context being deleted from pendingReadIndex; results mem leak. FIXES #7571
Implement raft readonly request described in raft thesis 6.4 along with the existing clock/lease based approach.