Map-Reduce Data Skew Handling via Marker Queue
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Solution Overview
Problem
Data skew in map-reduce operations leads to inefficiencies, where some computing devices remain idle due to uneven data distribution across databases, resulting in prolonged processing times and underutilization of computer resources.
Innovation Solution
Implementing a computer cluster that uses map-reduce operations to distribute identifiers of databases across nodes, generating markers that are stored in a queue, allowing nodes to repurpose and perform copy operations once reduce operations are completed, thereby ensuring continuous utilization of resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If data is distributed evenly across databases, then processing time is reduced and resource utilization is improved, but data skew cannot be addressed when data is inherently unevenly distributed
Solution Approach 1:
The patent segments the data copying process into distinct map and reduce phases. The map phase distributes identifiers across nodes, while the reduce phase handles actual data copying. This segmentation allows nodes to be dynamically reassigned from map to reduce operations, enabling efficient handling of skewed data distributions without increasing overall processing time.
Solution Approach 2:
The patent implements dynamic node assignment where computing nodes can transition between different operational phases (map, reduce, copy) based on current workload and data distribution characteristics. This dynamic reassignment ensures that nodes processing smaller data portions can be reallocated to assist with larger data portions, maintaining high resource utilization despite data skew.
2Productivity
If multiple computing devices perform copy processes in parallel, then copying speed is improved, but idle computing devices occur when data is unevenly distributed
Solution Approach 1:
The patent ensures continuous useful action by implementing a queue-based system where computing nodes that complete their current tasks can immediately pick up new tasks from the queue. The master node continuously distributes work units to available nodes, eliminating idle time and ensuring that all computing resources remain productive throughout the data copying process, even when data distribution is uneven.
Solution Approach 2:
The patent incorporates feedback mechanisms where nodes report their completion status and workload to the master node, which then dynamically redistributes work. This feedback loop ensures that nodes finishing their tasks early are immediately reassigned new work, preventing idle computing resources and maintaining optimal copying speed throughout the parallel processing operation.
3Productivity
If a queue system is implemented to manage markers, then resource utilization is improved by reducing idle time, but system complexity increases
Solution Approach 1:
The patent implements a queue system that serves multiple functions: it stores markers representing data portions, tracks completion status, and enables dynamic task redistribution. This single queue structure handles both the coordination of parallel operations and the management of resource allocation, reducing the need for separate complex control mechanisms while maintaining high resource utilization.
Data Source
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AI summary
A system and method includes using a queue with map-reduce. The system includes a computer cluster that is to execute, by a first node, a first reduce operation on a first location of data to generate a first plurality of markers indicative of data at the first location of data and execute, by a second node, a second reduce operation on a second location of data to generate a second plurality of markers indicative of data at the second location of data. Responsive to generation of one or more markers, the computer cluster is to submit the one or more markers to a queue. Responsive to completing the first reduce operation by the first node, the computer cluster is to direct the first node to perform a first copy operation that copies first data identified by a first marker of the one or more markers in the queue.