An investigation into fault tolerance in the Synapse communication server
Abstract
Synapse is an open-source communication server designed according to the Matrix communication protocol. The Matrix protocol is decentralized, federated, and open source, providing complete control of the messaging server by the organization. Messages exchanged between users are end-to-end encrypted, and the protocol can also interact with other proprietary messaging systems and technologies, acting as a middleware. However, a fundamental issue for the widespread adoption of the protocol is its ability to continue its services even in the face of failures. In this sense, the objective of this work is to investigate, through a practical experiment, the ability of the Synapse server to tolerate failures and synchronize lost messages after their recovery.
Keywords:
High Availability, Fault Detection and Recovery, Fault Tolerance
References
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El-Dardiry, Y. (2022). Matrix crdt. [link]. Accessado: (22/03/2025).
Element (2025). Element secure communication platform. [link]. Accessado: (20/03/2025).
Heise (2019). Open source: Bundeswehr baut eigene verschlüsselte messenger-app. [link]. Accessado: (22/03/2025).
Ihle, C., Deifuß, F., Schubotz, M., & Gipp, B. (2022). Towards portable identities in the Matrix protocol. In 2022 IEEE 42nd International Conference on Distributed Computing Systems Workshops (ICDCSW), pages 88–89.
Jacob, F., Beer, C., Henze, N., & Hartenstein, H. (2021). Analysis of the Matrix event graph replicated data type. IEEE Access, 9:28317–28333.
Jacob, F., Grashofer, J., & Hartenstein, H. (2019). A glimpse of the Matrix: Scalability issues of a new message-oriented data synchronization middleware. In Middleware Demos and Posters 2019 - Proceedings of the 2019 20th International Middleware Conference Demos and Posters, Part of Middleware 2019, pages 5–6.
Karhu, J. (2023). German health professionals will communicate with each other through the open source matrix protocol. [link]. Accessado: (22/03/2025).
Kleppmann, M. (2022). Making crdts byzantine fault tolerant. In Proceedings of the 9th Workshop on Principles and Practice of Consistency for Distributed Data, PaPoC ’22, page 8–15, New York, NY, USA. Association for Computing Machinery.
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Matrix (2025b). Frequently asked questions. [link]. Accessado: (05/04/2025).
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Pastorio, A., Rodrigues, L., & de Camargo, E. (2020). Uma revisão sistemática da literatura sobre tolerância a falhas em Internet das Coisas. In Anais Estendidos do X Simpósio Brasileiro de Engenharia de Sistemas Computacionais, pages 57–64. Porto Alegre, RS, Brasil. SBC.
PostgreSQL (2025). Postgresql relational database. [link]. Accessado: (26/03/2025).
Preguiça, N., Baquero, C., & Shapiro, M. (2019). Conflict-Free Replicated Data Types. In CRDTs, pages 491–500. Springer International Publishing, Cham.
Pätsch, S. (2021). German health professionals will communicate with each other through the open source matrix protocol. [link]. Accessado: (22/03/2025).
RedHat (2025). Red hat openshift. [link]. Accessado: (20/03/2025).
Schipper, G. C., Seelt, R., & Le-Khac, N.-A. (2021). Forensic analysis of Matrix protocol and riot.im application. Forensic Science International: Digital Investigation, 36, 301118. DFRWS 2021 EU - Selected Papers and Extended Abstracts of the Eighth Annual DFRWS Europe Conference.
Shapiro, M., Preguiça, N., Baquero, C., & Zawirski, M. (2011). Conflict-free replicated data types. In Stabilization, Safety, and Security of Distributed Systems, pages 386–400. Springer Berlin Heidelberg.
Sparber, J. (2020). Blockchain-based end-to-end encryption for Matrix instant messaging.
Sule, M.-J., Zennaro, M., & Thomas, G. (2021). Cybersecurity through the lens of digital identity and data protection: Issues and trends. Technology in Society, 67:101734.
Tchap (2025). Tchap, instant messaging for the public sector. [link]. Accessado: (20/03/2025).
Twisted (2025). Twisted: An event-driven networking engine. [link]. Accessado: (27/02/2025).
Zulip (2025). Zulip chat and collaborative open source platform. [link]. Accessado: (20/03/2025).
Published
2025-05-19
How to Cite
STOCKER, Vinicius; CAMARGO, Edson Tavares de; DE BONA, Luis C. E..
An investigation into fault tolerance in the Synapse communication server. In: FAULT TOLERANCE WORKSHOP (WTF), 25. , 2025, Natal/RN.
Anais [...].
Porto Alegre: Sociedade Brasileira de Computação,
2025
.
p. 57-70.
ISSN 2595-2684.
DOI: https://doi.org/10.5753/wtf.2025.8814.
