1. The CoBFIT Toolkit PODC-2007, Portland, Oregon, USA August 14, 2007 HariGovind Ramasamy IBM Zurich Research Laboratory Mouna Seri and William H. Sanders PERFORM Research Group University of Illinois at Urbana-Champaign

2. Overview Component-based framework for Intrusion Tolerance Software toolkit built by PERFORM research group at Illinois Includes a protocol suite for efficient replication with dynamic groups –Asynchronous system model –Byzantine fault tolerant (BFT) –Evaluated on LAN and WAN (Planetlab) settings Implemented in C++ –using the ACE object-oriented network programming framework To be released under open-source license

3. CoBFIT Components Framework ComponentsProtocol Components Reusable foundation for implementing & testing distributed fault-tolerant protocols [Euromicro 2004] Event handling Network communication Management of protocol components – protocol component hierarchy – direct dispatching of messages Cryptographic primitives – using Gutmann’s Cryptlib Implement various asynchronous Byzantine-fault-tolerant protocols Consistent, Reliable, & Atomic Broadcast Binary & Multi-valued Byz. Agreement Replication Protocols – APE or Async. Parsimonious Execution [IEEE-TDSC 2007] – PABC or Parsimonious Async. Atomic Broadcast [OPODIS 2005, SRDS 2007] – Interfaces with client- & server-side applications Group Management [Ramasamy05] – Group Membership Agreement – Group Reconfiguration Manager – Policy-based Admission control – Policy-based Failure Detection – Variants of APE and PABC with dynamic groups, virtual synchrony guarantees

4. Distinguishing Features of the Protocol Suite Replication protocols are parsimonious –Achieve amortized optimal efficiency despite asynchrony –Metrics of interest message complexity of atomic broadcast (agreement) overall resource usage (execution) –Previous works were either asynchronous or optimally efficient, but not both Replication protocols in asynchronous model with dynamic groups –Previous works were either asynchronous or with dynamic groups, but not both

5. Vizir Graphical User Interface User-friendly interface implemented in Java using JGraph Central console for deployment and management of a group –Define attributes of a server –Define connection topology of a server group –Specify/alter fault tolerance requirements Automatic instantiation of appropriate group size –Monitoring execution of group members –Controlled fault injections

6. Utility of CoBFIT Reduced development and testing time for new BFT protocols –Similar protocols that require a group abstraction can be quickly implemented and tested by interfacing with CoBFIT components Protocols components are modules that can be used individually or as a building block for providing more complex properties Easy deployment, run-time monitoring, and management of distributed set of servers using Vizir GUI

7. Vizir GUI - Drawing Mode Save configuration onto an XML file Define node attributes Define connection topology

8. Vizir GUI – Connected & Testing Mode test/deploy a preset protocol config. monitor execution Load topology from XML file Specify fault tolerance

9. Testing Individual Protocols Instantiate preset protocol configs. for testing Change protocol parameters at run-time Monitor execution (log messages & status bar)

10. Asynchronous Dynamic Replication Group with Virtual Synchrony Tower of Hanoi Appl.: Client sends disk-move requests; upon identical replies from a quorum makes actual move Replicas can be added or removed, while group maintains state consistency

11. Contact Info HariGovind Ramasamy –hari.ramasamy@gmail.comhari.ramasamy@gmail.com Mouna Seri –seri@crhc.uiuc.eduseri@crhc.uiuc.edu William Sanders –whs@uiuc.eduwhs@uiuc.edu