Adaptive Port Ceiling Assignment for Heterogeneous Storage I/O
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems face challenges in managing port bandwidth for background I/O operations between heterogeneous storage arrays, leading to potential starvation of bandwidth for host I/O operations due to unpredictable port speeds and the need for frequent code updates.
Innovation Solution
A port manager is implemented to dynamically determine the maximum throughput of each port by generating test I/O operations, identifying a throughput inflection point, and setting an adaptive ceiling based on a percentage threshold, thereby limiting background I/O operations and ensuring sufficient bandwidth for host operations without requiring hard-coded values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If background I/O operations are allowed to use available port bandwidth without limits, then data migration efficiency is improved, but host I/O operations may suffer from bandwidth starvation
Solution Approach 1:
The system dynamically changes the bandwidth allocation parameter (port ceiling) based on detected port speed characteristics. Through test I/O operations, the system identifies the throughput inflection point and sets the port ceiling as a percentage of maximum throughput, allowing adaptive adjustment between background I/O efficiency and host I/O bandwidth guarantee without fixed hard-coded values
Solution Approach 2:
The port ceiling is implemented as a dynamic limit rather than a static configuration. The system continuously monitors port performance through test operations and adjusts the background I/O bandwidth ceiling accordingly, enabling the allocation to adapt to changing port speeds and conditions while maintaining the balance between migration efficiency and host I/O protection
2Reliability
If hard-coded port ceiling values are used to limit background I/O, then host I/O bandwidth is protected, but the system requires frequent code updates when port speeds change
Solution Approach 1:
The system performs self-characterization by automatically testing port speeds and identifying throughput inflection points through test I/O operations. This self-service approach eliminates the need for external code updates when port speeds change, as the system autonomously detects and adapts to new port characteristics, maintaining host I/O bandwidth protection while ensuring port speed compatibility
Solution Approach 2:
The system performs preliminary test I/O operations to characterize port performance before actual data migration begins. By pre-identifying the throughput inflection point and setting the appropriate port ceiling percentage, the system prepares the bandwidth allocation in advance, ensuring both host I/O protection and compatibility with the specific port speed without requiring code changes
3Measurement precision
If test I/O operations are performed to determine port throughput, then accurate port ceiling setting is achieved, but additional time and processing overhead is introduced
Solution Approach 1:
The test I/O operations are performed as a preliminary characterization step during system initialization or when port conditions change. By completing the throughput measurement in advance, the system establishes accurate port ceiling settings before actual data migration begins, ensuring precision without continuously incurring the time overhead during operational phases
Data Source
AI summary
A port manager is configured to implement adaptive port ceiling assignment for background Input/Output (I/O) operations between heterogeneous storage arrays. The port manager generates a set of test I/O operations, applies the I/O operations to a port under test, determines a response time to complete the I/O operations on the port under test, and compares the response time of the current test with response times of a set of previous tests. Based on the test values, the port manager identifies a throughput inflection point for the port under test, which is used to set a maximum throughput of the port under test. The adaptive ceiling for the port under test is then set based on the maximum throughput times a ceiling percentage threshold value. The determined adaptive ceiling value is then used to prospectively limit background I/O operations on the port under test.