Master Thesis: Externalize State between Processes

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About this opportunity:

Radio Access Networks (RANs) consist of functions with stringent requirements for performance, availability, and resilience. These functions run on modern multicore architectures in embedded and cloud environments, where the ability to recover from failures is fundamental.

Multiple instances of the same RAN function may be deployed to improve resilience. An instance may be restarted, upgraded, or temporarily unavailable while another continues providing the service. RAN functions may also be partitioned by cells, users, bearers, or other traffic domains, with each instance maintaining state for the network and traffic it handles.

When state is kept only in an individual process, restarting that process may require the state to be reconstructed or may cause service interruption. Externalizing some or all state allows another process to access or restore it, potentially improving resilience and reducing the impact of restarts. However, this introduces challenges related to performance, consistency, synchronization, memory management, traffic migration, and implementation complexity.

This thesis will investigate state externalization between separate processes and evaluate methods for implementing it in a high-performance RAN packet-processing context. One method of particular interest is the DPDK multi-process model, which allows multiple processes to use shared DPDK resources such as memory, rings, mempools, and message-passing mechanisms. The thesis will assess this model's suitability and limitations for sharing or externalizing state between RAN function processes.

The thesis will consider two processes providing the same RAN function and handling a common traffic domain. An externalized state mechanism will allow one process to access, update, or restore state maintained by the other process or by a shared state component. The processes may either operate active-active for all traffic, or one may be active while the other is a cold standby. If the active process restarts, the standby becomes active and continues handling the same traffic.

The thesis will investigate and compare suitable state-externalization methods, potentially including shared memory, inter-process messaging, state replication, and the DPDK multi-process model. The DPDK approach should be implemented or evaluated as one candidate method.The investigation should address the technical feasibility and operational consequences of the selected approaches, including:

• Which state must be externalized and which state can be reconstructed locally.
• How state is shared, replicated, accessed, and updated.
• How consistency is maintained during normal operation and process restart.
• How traffic is assigned or migrated between processes.
• Whether packet loss, packet reordering, latency, or throughput degradation occurs.
• How the solution behaves while the standby process is synchronized or activated.
• The memory, CPU, synchronization, and implementation overhead.
• The limitations and dependencies introduced by each mechanism.

What you will do:

• Investigate current research and engineering approaches for externalizing and sharing state between processes, with emphasis on high-performance packet-processing systems.
• Select and compare suitable state-externalization methods. Prototype at least one method with the DPDK multi-process model as a primary candidate.
• Measure the impact on RAN function performance (e.g., traffic throughput, resource consumption, migration time, ...)
• Assess the expected resilience improvement compared with a design in which state is kept only within an individual process.
• The thesis will be concluded with a result presentation for the Ericsson team.

The skills you bring:

• Master's students in electrical engineering, computer science, or similar.
• Interest in high-performance packet processing, distributed systems, or resilient software.
• Interest in process communication, state management, and performance evaluation.
• Analytical approach with the ability to investigate, prototype, and evaluate solutions.
• Clear technical communication skills, both written and verbal.

Why join Ericsson?
At Ericsson, you'll have an outstanding opportunity. The chance to use your skills and imagination to push the boundaries of what's possible. To build solutions never seen before to some of the world's toughest problems. You'll be challenged, but you won't be alone. You'll be joining a team of diverse innovators, all driven to go beyond the status quo to craft what comes next.

What happens once you apply?
Click Here to find all you need to know about what our typical hiring process looks like.Encouraging a diverse and inclusive organization is core to our values at Ericsson, that's why we champion it in everything we do. We truly believe that by collaborating with people with different experiences we drive innovation, which is essential for our future growth. We encourage people from all backgrounds to apply and realize their full potential as part of our Ericsson team. Ericsson is proud to be an Equal Opportunity Employer. learn more.

Primary country and city: Sweden (SE) || Linköping

Req ID: 792024