Client Session Recovery in Distributed Storage Systems

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In modern distributed storage systems, clients often lose storage sessions due to failures, leading to overhead in creating new sessions, which can disrupt access and increase downtime, especially when clients function as servers for other devices.

Innovation Solution

The technology enables clients to detect and recover existing storage sessions by providing indications to the distributed storage service, obtaining session data from devices that previously accessed the storage objects, allowing for quicker recovery and reduced overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If clients create new storage sessions after failure, then access can be restored, but overhead increases and downtime extends

Engineering Contradiction:

Improveaccess restorationVSAvoiddowntime

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by preserving session state information and device context before failure occurs. When failure is detected, the client can resume from the preserved state rather than starting fresh, thereby reducing downtime while restoring access.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the distributed storage service monitors client status and provides session recovery indications. This feedback loop enables the client to detect failure conditions and initiate recovery using preserved session state, balancing access restoration with minimized downtime.

Inventive Principle:

Principle #23Feedback

2Reliability

If clients create new storage sessions after failure, then access can be restored, but computing load on downstream devices increases

Engineering Contradiction:

Improveaccess restorationVSAvoidcomputing load

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

Instead of discarding session state upon failure and requiring complete recreation, the system recovers preserved session state information. This approach restores access while avoiding the high computing load of creating entirely new sessions, as the recovery process reuses existing session data and device context.

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If session data is preserved for recovery, then failure recovery is enabled, but device complexity increases

Engineering Contradiction:

Improvefailure recoveryVSAvoidsession management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system extracts only the essential session state information and device context needed for recovery, separating this critical data from the rest of the system operations. By taking out only the necessary recovery information, the system enables failure recovery without proportionally increasing overall device complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS10884863B2Client session reclaim for a distributed storage system

Publication Date: 2021.01.05 RED HAT INC

AI summary

The technology disclosed herein that may enable a client of a distributed storage system to recover a storage session after a failure occurs. An example method may include: identifying a storage session of a distributed storage service, the storage session comprising session data that corresponds to a storage object of the distributed storage service; providing, by a processing device of a client, an indication that the client is recovering the storage session; and obtaining, by the client, the session data of the storage session from one or more devices that accessed the storage object of the distributed storage service.