Dynamic Cache Node Selection for P2P Data Forwarding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cache coherence protocols in multi-core systems, such as MOESI and MESIF, lack flexibility in selecting cache nodes for peer-to-peer forwarding, leading to performance bottlenecks due to static designation of nodes without considering factors like location and workload, resulting in inefficient data transfer and potential bottlenecks.
Innovation Solution
A dynamic selection mechanism where a home node, using a logic unit cluster and directory, identifies cache nodes marked as 'Shared' based on selection parameters like topology and workload to forward data directly between cache nodes, bypassing the need for 'Owned' or 'Forward' states, thus optimizing data transfer paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If MOESI or MESIF protocols are used to implement peer-to-peer cache forwarding, then latency is reduced compared to traditional directory-based coherence, but the protocols lack flexibility in selecting cache nodes based on performance factors such as location and workload
Solution Approach 1:
The patent applies dynamics by transitioning from static cache node designation (MOESI/MESIF protocols that always select the same node based on fixed state bits) to dynamic selection based on real-time performance factors. The home node dynamically selects source nodes considering location proximity and current workload conditions, making the system adaptive rather than rigid.
Solution Approach 2:
The patent changes the selection parameters from simple state bits (Owned/Forward states) to multiple performance parameters including location distance and workload metrics. This allows the system to evaluate multiple cache nodes based on current system conditions rather than relying on fixed protocol states.
2Reliability
If the designated cache node is selected based on fixed protocol states (Owned in MOESI, Forward in MESIF), then cache coherence is maintained, but the designated node may become a processing bottleneck causing performance degradation
Solution Approach 1:
The patent implements feedback mechanisms where the home node monitors performance factors such as node location and workload conditions. Based on this feedback, the home node dynamically adjusts source node selection to avoid bottlenecks while maintaining cache coherence, rather than relying on fixed protocol states.
Solution Approach 2:
The system allows cache nodes to serve themselves as source nodes based on their current capabilities and conditions. Instead of being forced into fixed roles by protocol states, nodes can voluntarily respond to requests when they have the data and capacity, improving overall system throughput.
3Adaptability or versatility
If directory-based coherence is used instead of snooping-based coherence, then scalability and bandwidth concerns are improved, but longer latencies are caused due to constant access of the home node
Solution Approach 1:
The patent uses the home node as an intelligent intermediary that maintains the directory but enables direct peer-to-peer data transfer. The home node mediates the initial request routing and source node selection, then allows direct forwarding between cache nodes without requiring subsequent home node involvement, combining directory-based scalability with low-latency direct access.
Data Source
AI summary
A home node for selecting a source node using a cache coherency protocol, comprising a logic unit cluster coupled to a directory, wherein the logic unit cluster is configured to receive a request for data from a requesting cache node, determine a plurality of nodes that hold a copy of the requested data using the directory, select one of the nodes using one or more selection parameters as the source node, and transmit a message to the source node to determine whether the source node stores a copy of the requested data, wherein the source node forwards the requested data to the requesting cache node when the requested data is found within the source node, and wherein some of the nodes are marked as a Shared state corresponding to the cache coherency protocol.