1 / 37

e POST Serverless Email System

e POST Serverless Email System. http://www.epostmail.org/ POST: A Decentralized Platform for Reliable Collaborative Applications Seo, Dong Mahn 16 th June, 2005. Contents. Introduction Background Scoped Overlays POST Design ePOST Design Related Work Current Version Conclusions.

arama
Download Presentation

e POST Serverless Email System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. ePOST Serverless Email System http://www.epostmail.org/ POST: A Decentralized Platform for Reliable Collaborative Applications Seo, Dong Mahn 16th June, 2005

  2. Contents • Introduction • Background • Scoped Overlays • POST Design • ePOST Design • Related Work • Current Version • Conclusions

  3. Introduction

  4. Introduction (1) • POST • Three basic services • Secure persistent single-copy storage • Metadata based on single-writer logs • Event notification • Wide range of collaborative applications • Scalability, resilience and self-organization • From users • CPU, disk space, network bandwidth

  5. Introduction (2) • ePOST • Cooperative, serverless email system • Storage, Network bandwidth from users • Provides • A severless, peer-to-peer email service • Secure email among ePOST users • An organically scaling service that requires no dedicated hardware • Very high availability and data durability • Compatibility with POP/IMAP clients, SMTP mail servers

  6. Background (1) • Email Systems • Simple Mail Transfer Protocol (SMTP) • Post Office Protocol (POP3) • Internet Message Access Protocol (IMAP) • Webmail

  7. Background (2) • Peer-to-Peer Overlays • Pastry • structured overlay network • self-organizing, highly scalable, and fault tolerant • unique identifier (160-bit id space)

  8. Background (3) • Peer-to-Peer Overlays • PAST • distributed storage system • Distributed Hash Table (DHT) • Content Hash Blocks • Certificate Blocks • Public-Key Blocks

  9. Background (4) • Peer-to-Peer Overlays • Scribe • group communication system • 160 bit groupId • multicast tree

  10. Scoped Overlays (1) • Design • Multi-Ring Protocol above the Key-Based Routing (KBR)

  11. Scoped Overlays (2) • Ring structure

  12. Scoped Overlays (3) • Gateway nodes • one in each ring • use the same nodeId in each ring • Routing • target ringId • anycast • Global lookup • ringId

  13. Scoped Overlays (4) • Multi-level ring hierarchies

  14. POST Design (1) • User accounts • identity certificate as a certificate block • secure hash of the users’ name as the handle • description of the user • contact address of the user’s current trusted node • any references to public metadata associated with the account • public-key block • signed with user’s private key

  15. POST Design (2) • Single-copy store • convergent encryption • allows a message to be disclosed to selected recipients • ciphertext (cryptographic & cipher)

  16. POST Design (3) • Event notification • alert users and groups of users to certain events • availability of a message. change in the state of a user, change in the state of a shared object • Advanced Encryption Standard (AES) with a unique session key

  17. POST Design (4) • Metadata • single-writer logs • Ivy • The log head and each log record are stored at a different set of nodes. • Garbage collection • removing objects from the DHT • Lifetime

  18. POST Design (6) • POST Security • Threat model • Data privacy • Data integrity • Data durability • Denial of service • Freeloading

  19. ePOST Design (1)

  20. ePOST Design (2) • Email storage • Email messages and MIME components in POST’s single-copy store. • Email delivery • using POST’s notification service • Email folders • encrypted POST log

  21. ePOST Design (3) • Incremental Deployment • interoperate with server-based email infrastructure • Management • Software distribution • Storage • Access • Discussion • Feasibility, Mailing Lists, Spam

  22. Evaluation (1) • Timeline • from Sept. 19, 2005 to Nov. 12, 2004 • average 26 nodes • Linux and Windows

  23. Evaluation (2)

  24. Evaluation (3)

  25. Evaluation (4)

  26. Evaluation (5)

  27. Evaluation (6)

  28. Evaluation (7)

  29. Evaluation (8)

  30. Evaluation (9)

  31. Evaluation (10) • Single-Copy Store • reduce the storage load by 6.1% • 30 users • 300,000 email messages • 2.8 GB • reduced to 3.2GB of unique data • savings of 15.5% • 254% increase in the effect of the single-copy store.

  32. Evaluation (11)

  33. Evaluation (12)

  34. Related Work • Collaborative Applications • SENGMSG program, FTP, SMTP, POP3, IMAP • Lotus Notes, MS Exchange • Scalability • Porcupine System • Hotmail, Google • Security • spam, phishing scams • PGP, GPG, DNS tricks • Peer-to-Peer Applications • DHT • OceanStore project, Kademlia, eDonkey2000 • Coral-CDN, OpenDHT

  35. Current Version • ePOST 2.4.2 • 27 May 2005 • Rings • Rice University Ring (rice.epostmail.org) • Open Membership Ring (open.epostmail.org) • based on PlanetLab nodes • Future Features • individual domain names • multiple, simulations proxies • multiple ePOST accounts

  36. Conclusion • POST • decentralized, serverless messaging system • highly resilient and scalable messaging service • enduring confidentiality, data integrity, and authentication • ePOST • easily provide • instant messaging, newsgroups, calendars, and shared whiteboards

  37. Thank you !

More Related