Subject: [Blockchain-interop] Gatweay Crash Recovery Discussion #1

From: Rafael Belchior <[email-masked]>
Date: Mon, 30 Nov 2020 16:49:30 +0000

Dear All,
Attached, the slides of the first discussion on the crash recovery 
mechanism for gateways, that took place during the last meeting.

Cheers,

-- 
Rafael Belchior
Ph.D. student in Computer Science and Engineering, Blockchain - Técnico
Lisboa
https://rafaelapb.github.io/
https://www.linkedin.com/in/rafaelpbelchior/

---

From: Thomas Hardjono <[email-masked]>
Date: Mon, 30 Nov 2020 21:31:22 +0000

Thanks Rafael,

This is a great start to begin to address the various aspect of the crash-recovery.

A couple of questions:

-- Which mode (self-healing mode, or primary-backup mode) do you recommend?  (Which one would be the simplest approach for now, and what assumptions would we need to make).

-- Could we assume that the gateway that recovers (i.e. recovers or takes-over) has authenticated access to the log-metadata file.

-- thomas --

________________________________________
From: Blockchain-interop [[email-masked]] on behalf of Rafael Belchior [rafael.belchior=[email-masked]]
Sent: Monday, November 30, 2020 11:49 AM
To: [email-masked]
Subject: [Blockchain-interop] Gatweay Crash Recovery Discussion #1

Dear All,

Cheers,

---

From: Rafael Belchior <[email-masked]>
Date: Mon, 30 Nov 2020 22:21:55 +0000

Thomas,
Thanks for your questions.

Inline:

A 2020-11-30 21:31, Thomas Hardjono escreveu:
> -- Which mode (self-healing mode, or primary-backup mode) do you
> recommend?  (Which one would be the simplest approach for now, and
> what assumptions would we need to make).

The self-healing mode is simpler, as the same machine eventually 
recovers, continuing its operations since the latest log entry. It does 
not require, in principle, to read from the log storage API. However, we 
are assuming it eventually recovers, and while this happens the system 
is down, prejudicing availability.

> 
> -- Could we assume that the gateway that recovers (i.e. recovers or
> takes-over) has authenticated access to the log-metadata file.
> 

That is correct. We assume the communication gateway-storage is done 
through a safe channel (e.g., TLS/HTTPS), and on top of this, we could 
have OAuth. We could encode the access control policies into the "access 
control profile" field of the log, or delegate such responsibility to 
the log storage API manager (as in, out of scope).

Hope this clarifies.
Cheers,
Rafael

> From: Blockchain-interop [[email-masked]] on
> behalf of Rafael Belchior
> [rafael.belchior=[email-masked]]