Hyperledger Foundation Hyperledger Sawtooth, 11 Feb 2021

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From YouTube: Why DAML? Write once & Deploy on Fabric & Sawtooth

Description

A virtual meetup hosted by Hyperledger Noida. At this virtual meetup with Anthony Lusardi from Digital Asset, we will look at why there is a need to design a programming language specifically for Smart Contracts and the Blockchains that power them.

More Daml resources are at: https://bit.ly/trydaml

More about the event is at: https://www.meetup.com/hyperledger-noida/events/276149890/

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Hyperledger – Open Source Blockchain Technologies

Hyperledger is an open source community focused on developing a suite of stable frameworks, tools and libraries for enterprise-grade blockchain deployments.
It serves as a neutral home for various distributed ledger frameworks including Hyperledger Besu, Fabric, Sawtooth, Indy, as well as tools like Hyperledger Avalon, Cactus and libraries like Hyperledger Aries, Ursa. Learn more about Hyperledger projects: https://www.hyperledger.org/use

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A

And you get some nice properties out of that too. But I'll talk about that in a little bit to get started, I'm going to give it just one more minute. Let's see some more people coming in now and then get going.

A

All right, I guess.

B

A

Get started with a pretty good amount of people in already and more people are joining, but I probably won't miss too much in my first few minutes so first off. I would very very much like to thank the hosts of this I'd like to thank aaron, kamlesh and vikram for helping put this together.

A

I really really appreciate it. I think that these sessions are great and I'm just really happy that uh we were able to make something work and.

B

Yeah, just to give you a little bit about myself, my name is anthony. I am a developer advocate at digital asset and we work on a programming language, slash tech, stack, called tamil uh demo doesn't stand for anything. It's just.

A

Stamina, it used to stand for something it does it anymore and yes,.

B

From for myself, you know I've long been interested in the more public blockchain space and as of last january, not this january. I started working at digital asset because I thought download was a really cool language because uh it solves a lot of coordination problems and private blockchains do in general that I think get overlooked a bit and are just really interesting problems to solve.

B

So one other thing to mention before I get started too, is that at the end of this we'll be doing a little giveaway. We have a demo certification course, and so the first, uh the first certification.

A

In that course is or examine in that.

B

Certification is uh the associate one, which is the very basic level, but we'll be giving it away for free and there'll, be a coupon code on the left screen about that. So if, at the end of this you're interested in learning demo, you know you can pick up the coupon code and then go ahead and and try out them a little bit and then, if you like it a lot.

A

B

Can go ahead and uh and just.

A

Take that exam and of.

B

Course you can register.

A

It ahead of time too, so I would snatch it up uh if you're at all interested once once it's on screen and.

B

Lastly, you can ask questions whenever you want I'm more than happy.

A

B

A

Answer them, so I'm going to be talking.

B

Of course, about demo and xaml is a very interesting language in that it's designed to be right once and run anywhere.

A

With respect to your persistence, back ends and uh other parts of your tech stack and so.

B

The first question most people might be asking themselves and probably been asking themselves for the past. 10 years is don't we already have all the programming languages we need and I'd say we don't. I would say that we have a lot of languages that do the same thing.

A

But in different ways and.

B

Even when it comes to languages that we have for blockchains and distributed ledgers, we find that they behave a lot like languages that are for their contemporaries.

A

For parts of uh the tech world that aren't.

B

Like blockchains, so we have languages that really act as if they weren't running on a blockchain or distributed ledger, and on be probably because of that. But on top of that we also end up in a situation where we're managing very low level concerns in our code.

A

B

A

Higher level language that I'll get into so really.

B

Demo differs in what it does.

A

B

What it does is becomes a portable language for dlts that really abstracts away the ledger itself. For you, uh you can it's not a great uh analogy, but you can think of this like how you don't always write code to commit to sql led to sql databases anymore. You kind of use libraries that do a lot of that for you and you can think of demos sort of like that, but it actually goes far beyond that.

A

And also these, this portability gives us quite a lot of features so really.

B

When we're talking about demo the things we get out of it and I'll actually go into this with some code examples and I'll show you a demo running, live.

A

But we end up with a demo being very.

B

Concise, it's really quick to prototype your use cases and you only focus on your business logic, not your infrastructure demo, actually from your templates, uh which you can kind of think of as classes in another language and I'll I'll show an example of them just derives everything that it needs for the back end from that, because demo is a very strongly typed language based on haskell and if you've ever written, haskell or another functional language, you might.

A

B

That oftentimes, when you're writing in those languages, you have to write a lot less because the compiler and the devil's case, the runtime, actually does a lot more of that work.

A

For you and demo's.

B

Particularly efficient in this, too uh demo is very secure by default. So what I mean by that is, we have these concepts called signatories, observers and choices.

A

And these basically.

B

Correspond to uh read, write and execute permissions in a unix system, they're similar in that way in that, when you're writing demo code in every single template.

A

You write, you are very explicit about which parties.

B

Can create a template can be responsible for being a signatory on it, which parties can read a template, can basically be an observer on it and which parties can execute. What on a template, uh basically having different choices on that contract that they can.

A

That they can exercise so.

B

These are all explicit upfront, and that gives you a lot of very nice security and privacy properties.

A

B

Also, you know very fit for purpose here when we're talking about distributed. Ledgers, we're talking about multi-party systems and damol is really designed for multi-party systems.

A

It's not so much designed for single party systems or systems where you know, essentially one one bit of of code is responsible for the entire thing. Demo is not really designed so much for that. It.

B

Could do it but.

A

I think you might find other tech stacks more useful in that case, uh demo is also portable. So when you write your demo app once it works across multiple platforms and.

B

That means that you don't actually have to change any code, uh the same code that you that- and I can actually show this if we have time for me to show deploying on both but.

A

The same code, you write.

B

For fabric and deploy to your demo runtime, you can then compile it and uh deploy to a download runtime. That's connected to sawtooth for.

A

B

And lastly, demo also is becoming much more interoperable, we're still working on this. So it's not perfect yet, but we have another part of our tech stock tech stack called canton. That is essentially going to enable different, disparate ledgers. So if you have a sawtooth node and a fabric node- and you have a dowel application and you want to run it on both and get a communication between both your fabric and sawtooth node via your demo, application you'll be able to do that.

B

You can actually try it out now at canton.io, but it's not, uh I wouldn't say it's ready for production in all cases right now and yeah. So that's, basically the the domino tech stack and so just briefly, we can think of demo as a and really depends on who you are so, if you're a developer, it's kind of a consistent language for distributed and relational databases, and you only need to know one of them in that way. It's also very similar to sql, in that you have a very common language for talking to these different.

A

Different ledgers.

B

It also reduces complexity when developing distributed applications, so if you're, a project manager or a developer, that might be very interesting to you because there's a lot less boilerplate code and a lot less.

B

uh I like to call it scaffolding um that you need to put up in order to get your application running, and this, of course, if you're, a decision maker results in faster, more accurate development of your distributed applications, because there's a lot less concerns for program, your developers to have to worry about, and so now we're going to get a little more technical.

B

This is starting to get into the technical part portion of this presentation. But- and of course, if you have any questions at any time, always feel free to interrupt, I really don't mind, but here's how demo looks and demo. This is an actual application that I'll I'll show in a little bit.

B

But demol essentially has these concepts called templates and what a template is is kind of like a class in an imperative language, and so when you're using demo, what you're doing is you're instantiating these templates much the way you would instantiate a class and then that's basically a sort of contract on the ledger where different parties can do different things.

B

So demo is very explicit. So, let's, let's get a little into this, uh you can see on the left under the proposal template uh there are arguments that it accepts. So here the beer proposal accepts a beer iou and then um that's basically the things you need to instantiate your template. So you need to provide it a beer iou in order to instantiate of your proposal and the reason we're doing this uh instead of just doing this in one template where we would just have the iu is because demo, like I said, is very explicit.

B

So this beer iou. If we look over here, we see that it requires a signatory of giver and recipient. That means it needs two signatures from two different parties in order to actually be instantiated.

A

uh So the way we we go about this is we create our first template, which has our signatory, which is the.

B

Giver, this is the person offering it.

A

The observer, the person receiving it these correspond to the given recipient.

B

On the right side of the screen, and then we have some things where it's sharing and then we have a set of choices and we have choices where the recipient can choose to accept this offer or reject it.

B

You know, maybe they don't drink beer or maybe they don't believe that this is an offer that they want to accept because they don't want to owe somebody something later and then uh we also have the option where the giver can actually cancel this proposal and one nice thing, one nice property of damol is this proposal here uh when you execute a choice on it, it's atomic and it archives that proposal after that choice is executed.

B

So that means you can end up in a situation where both except beer and cancelled beer are called at exactly the same time and both go through. There's no real worrying about race conditions here, because uh devil is.

A

A utxo based piece.

B

Of software that uh essentially make sure there can't be any conflicting state here, everything.

A

Is nice and atomic, and so.

B

The other thing to note here too, that's really interesting and cool. I think, is that the giver and recipient you can end up in a situation where somebody's written code, where, for example, I have an obligation to somebody else for for this proposal like I can. I can't automatically make my obligation for somebody else like I can't automatically say. Okay, I owe aaron something.

B

Aaron has to agree that I owe him that thing and that really helps avoid a lot of uh just issues down down the road where people may end up having obligations to each other, that they didn't intend, and so.

A

It's really nice that everything's explicit there and then.

B

uh Because somebody signs off because uh aaron say aaron goes and says, accept.

A

B

What will happen is uh it'll, go ahead and create this iou, and it can do that because now the proposal contract had my signature and the one other signature required for this iou was aaron's, and so then it gets created and then later aaron can actually mark that as received and there's actually quite a lot of functionality that we're getting in about 30 lines of code. Oh and I'm sorry, I haven't had the chat up so.

A

B

A

Seen the questions my I.

B

Apologize raphael says it's impossible to find anyone who can reject a free beer. uh Yes, exactly.

A

That's that's what you that's often.

B

Though you think, when you're coding these things and then you end up in a case where somebody would.

A

um And ram has a.

B

Good question here: what does pure do here basically within this functional context, is similar to what it does in haskell, which is it just does nothing uh pure is basically just kind of returning.

B

uh I forget what they call the thing in parentheses, but it's basically returning nothing and what that does as a consequence of the daml contract. Is it archives the beer proposal such that? No other things can happen, so your proposal is instantiated.

B

uh Somebody calls reject or cancel that exercise is pure and by the very action of calling that choice. uh This proposal gets archived. So that's. Why reject and cancel the same code? These are kind of uh really just niceties.

B

Actually, as the giver, I wouldn't need. This choice down here. Cancel beer, because this signatory, who is the giver here, uh doesn't always has the option to archive a contract archiving the contract is basically a choice that the signatory always has.

A

And so that's kind of how that works so.

B

How enforceable- and is this when we are trading settling stock uh demo, actually is being used um within the australian stock exchange hong kong exchange?

B

So if they trusted I'd, say anybody could trust it, uh but it is really actually designed for making sure that, when you're settling things between multiple parties that it is as safe as you can possibly get it and yeah. So that's a great question and then giovanni has the question here. Choices seem to be actions or possibilities uh that a signatory can perform.

B

Finally confirm: uh yes, a signatory or observer like like you, like you said there can, can perform these choices, but each and every choice also has a controller. So you can have a controller who's, a beer, dot recipient and can control some choices and the beer.giver can control other choices and say this iou.

A

B

Third party on it, but they weren't in the signatory or observer um you wouldn't be able to actually have them, do the choice they would have to be specified as an observer. At the very least.

A

In order to, in order to control choices, how do we query proposals for proposals.

B

Still on flight, that's a great question so.

A

You can query for uh things.

B

Commands submitted to the ledger that are still in flight, there's a variety of ways to do that, especially through the ledger api, the json api. I believe there.

A

B

A way to get the.

A

Active contract set so.

B

You can do that, uh so I can actually show you how it works in this code too. Is that when we when so when I go through the code here, what I'll show? You is a query where I ask for all the beer proposals and then get them back for the user?

B

That's asking for them and I actually ask for them in a very broad way where I try to get back more data than I can than I should um and demo then goes ahead and enforces that I only get back the data that I'm supposed to see.

A

um For a choice to enforce do we need controller signatures, um yes, sort of what, for a.

B

Choice to execute you basically need the controller to be the one uh submitting that transaction to the ledger. So, for example, this reject beer. The recipient needs to actually sign a transaction themselves uh with their authority to go ahead and reject the beer and.

A

Yeah, that's kind of how it works.

B

Also, signatures are a little different here in that they're really managed by the node that you're talking to, and then you have a permission layer in between that say oauth or some other iam.

B

That is responsible for making sure that that that it itself can can sign for that recipient that that recipient has the right token to say.

A

uh They're, the right person or the right party, uh because parties aren't always people, sometimes parties can be organizations or groups within an organization. So that's what demo looks like and these.

B

Are great great questions so always feel free to keep them coming um and then dabo actually goes ahead and produces uh or powers front ends that look exactly like this. This is all the code I wrote in view.js uh for my demo frontends. You can actually they'll write code. uh Demo has support for java and javascript, um essentially for easily making a variety of classes that it just generates from your code that make it very.

A

Easy to interact with your with your pro with.

B

uh Your underlying demo ledger and the nice thing there too, on the javascript side is it actually generates typescript, but you can use that from vanilla. Javascript like I did here, you just don't get the nice type enforcement that typescript gives you.

A

B

So let's actually go ahead and check out a toy production app and we're going to check out the oh beer app like I talked about before. So what we're going to do now is we're going to live, deploy this application, so I'm going to deploy this to fabric.

A

And what I'm going to do is go to our demo on fabric repository.

B

What I would normally do is, I would make sure my fabric tools are installed. I would set up my path and then I would go ahead and get clone. um The one thing that I'm going to skip here is the cloning just because once I get down to these steps, uh it starts downloading a bunch, docker images and building them, and that takes a little bit so I've already pre-built these so that they're ready to go and one.

A

Thing I'm going to do uh before I do. This is make sure I'm not running.

B

Any other docker images right now.

A

And that was running some so need those all right. Let's go ahead and navigate into this directory here and then we're going to run gen.sh, which basically.

B

Generates a config for us there's. Actually you can actually manage the configuration yourself as.

A

Well, uh it's in config.tx, but it's in a different, folder and yeah, so that just generates a quick test config for us. Basically, and then we go ahead and start a fabric and.

B

So what this is doing is starting up the.

A

Fabric instance itself, um so that's uh that's up and running now and.

B

Now, what we're going to do with our fabric instance is we're going to start our demo driver to run against that instance. So I'm going to hop over here to the deployment guide, this deployment guide actually was written for a different application called create demo app. But one of the nice things about download is that the deployment.

A

Is so similar? I can just use this one for my different application.

B

So now we're going to run the download driver, which is basically the interoperability layer here that is going to talk between our demo code and the fabric instance and allow data to be re.

A

Read and written from it so we'll start that up, that's actually going to.

B

A

B

Moment so, while we're doing that, I'm going to go ahead and build my demo app.

A

So the app that I'll be building today is called oh beer, it's for owing your friends, a beer, it's actually a double pun, uh big o, notation and so.

B

We're going to do here is dab mall.

A

Build which will build the application and then we're going to run demo code js and in.

B

A little bit too, once I have the application up and running I'll, actually show you some of.

A

B

A

Behind this, uh particularly with respect to the front end and how downline forces some of these nice things so with coach and js now, what that's done is and actually I'll show you this now, because it's a good sign too, is it's gone ahead and taken our demo models which are over here. This is basically the same code that I was showing you on the slide, plus some tests and what it's done is it's created all these other nice um nice little classes here, and we can actually go ahead and import this.

A

So all the classes related to here so we'll have a beer dot. uh Beer proposal or beer duck feared up your proposal uh that we can actually go ahead and access. So right here we see that we have this nice little class that we just made for us, and we can even see that it has all these choices on it and we didn't have to write any of this code or show um teach our application how to interact with our backend.

A

This was all just made for us, which is very, very nice, um so I can go ahead and just query this. The ledger with that we've got another question here: do we have to know haskell to debug the runtime?

A

um I don't think you're going to end up in a situation where you need to really.

B

Debug the runtime, uh so I wouldn't worry too much about that. If you were, if you wanted to modify or change the the runtime, then uh I'm not sure, because I don't actually work on that. That's a great question that could actually be the type of question that you could ask on our forum.

A

B

Could ask you know you know you can go to discuss.com click on new topic and ask the question in the questions category.

B

But personally I I wouldn't worry too much about that, because um if you reach a point where you meet where there's a bug in the runtime, um that's that's something that that we have quite a lot of developers on our ends of digital. I said you know we are a company of about 150 people now.

A

B

Yeah, I wouldn't worry too much about that, but I would imagine that I know the demo compiler is to more closely answer your question. I know the demo compiler uh does use ghc on the back end, so that's very much haskell and then uh the demo runtime, I imagine, parts of a uh would use would be related to haskell because we have a lower level language called demo. Lf, that's basically a stripped-down demo that our demo application compiles down to and uh then that is then there's probably other code in there.

B

That is not pastel but chain code and other things and probably also depends on what ledger you're talking to so yeah. I I apologize, but I can't answer that question perfectly so anyway. um Kind of related to that actually, though, is like I said, download compiles down to.

A

B

Down to a dowmlf, which is a lower level language that actually runs on our on our download driver, and it has a dar file when it produces this and that you is actually very similar to a jar file in java, and that is the self-contained zip file that has all the parts of the application that you need to deploy.

A

And you're very welcome, then yeah. So anyway,.

B

Now we're going to go ahead and deploy this application, because I assume our download driver is up and running and it is, you can actually see uh we're running on port 6865 over here and then, if we come over here, you can see that uh our fabric node, has actually been talking to our runtime when the runtime was getting itself set up. So now we're going to deploy the code and in order to do that, we'll hop over to our deployment guide and right here we have this nice little command down will deploy.

B

I built this application, but download deploy actually rebuilds it, but none of the codes changed in between so it doesn't really matter.

B

So it's deploying- and it's also uh allocating a couple parties that we're going to use for testing everything in a little bit, and what you can see here is that there was a bunch of data written uh that came through to our table driver and then was also written.

A

B

Our fabric node, and so that's kind of how that works, and now something else we get for free is our json api. So this is actually. This is nice for two reasons: one! You don't need to build out your own json api. Everything is provided for you and is very easily implemented on the front-end side. The other nice thing about this is that once you're used once you've written one demo, application you'll know how to use the auto-generated api that you get and you can go ahead and use it again.

B

It in almost exactly the same way: you're just changing out templates and what you're.

A

B

A

So that's really really nice to have so that's going to get started.

B

A

Now that'll just take a moment and.

B

Yes, so, while that's getting started off, I'm going to set up the front end with the front end, so the one thing I do need to do is I need to make sure I have the right ledger.

A

Id so um you know.

B

Depending on what you build, this thing it'll be different, how you specify it, but the front ends, and the json api in particular want to make sure that, when you're talking to them you're requesting the right ledger, this is good for when you're developing, so that you can have a legend called development and you could have one in call production.

B

And then you never end up in a situation where your ui is accidentally talking to production when it should be on development, and vice versa.

A

So just a nice little thing there, let's see if our json.

B

Api is up, it is, and now it's running on on port 7575 and that's where we're going to go ahead.

A

And talk to it so the commands.

B

Here are actually for starting up a little react app, so I'm going to do it slightly differently. I'm going to hop over to my readme for starting my ui. I've already ran your install since we don't want to wait for everything and I'll go.

A

Ahead and run yarn serve within my ui.

B

Directory and then in a moment we'll get our front end and be able to to talk to our.

B

B

And so yeah this is this is our, but then so I'm going to go ahead and log in as alice you'll see right here, I'm just typing in names. We do actually have.

A

Facilities to do proper.

B

Full authentication, but this is just an example app and one thing we released or are in the process of releasing right now um with the 110 release. Candidate and stable, is hopefully coming out next week is a middleware for oauth, so that actually implementing the oauth workflow is, is now very easy in demo. So I'm actually waiting to be able to update my application in order to take advantage of that, and so as alice, I've just offered boba beer and a lot for carol one too, and so we're gonna get separation of concerns.

B

Here, uh bob and carol aren't going to be able to see each other's and alice is only going to be able to see the ones that they.

A

Owe each other as well and.

B

I can actually demonstrate how you know they. Each of these users is really only able to get the data that they're supposed to, and that's right over here uh you can see in.

A

Get beer proposals what.

B

Alice did when she logged in, or I can actually log out and log back in now uh to just from that bit of code and make sure it's pulling it right when alex logged in uh she said to the ledger: hey ledger, I'm I'm doing a query and I want all the beer proposals. I don't want them limited just to me. I want everything and the lender went ahead and said. Okay, here are the proposals you can see um and she wasn't able to see any of the ones that she couldn't.

B

So, for example, I can go ahead and log in as bob.

A

B

See that offer from alice, but as bob I can actually go ahead and offer carol a beer too and I'll I'll go ahead and accept the one from alice. So we can see that. But what we'll see is when we log back in as alice.

A

Alice went and requested every proposal.

B

But bob's proposal or bob's offer um isn't going to appear here because that was between bob and carol and that and alice wasn't involved and so alice can go ahead then say: cancel her offer to carol and bob could later go in.

A

And accept it, except uh his offer from alice.

B

And then you know, carol can go ahead and accept.

A

B

A

From bob, for example, and mark that is received as well, and what.

B

You'll, see too is that uh data is actually you know going it's coming through the ledger api and then it's hitting our download driver and then our demo driver is committing it to our fabric instance. So that's basically it all in a nutshell.

B

uh But then, since we have some time and obviously I can also answer questions, if you have any more, but what we can do now is we can go and take that code that we wrote and go ahead and deploy it not to a fabric instance, but.

A

To a sawtooth instance, so I'm gonna first just get rid of all my other containers.

A

And I'm gonna head to my demo on sawtooth repository and this.

B

One's going to just be slightly different one of the reasons I like showing the fabric one first.

A

B

Fabric when we're when we're going through the process of starting it, this one actually starts up a sawtooth node and our downhill driver together. So it's kind of nice to separate those uh for demonstration purposes, but yeah. Let me show you.

A

That did one take down my ui okay.

B

So yeah, this is the forum by the way, too. um I definitely recommend if you get interested at all in demo, check out the forum and go ahead and click this link, and you can actually have a bunch of useful links uh for you to check out to kind of learn downloading it and get an understanding about it. If you're interested in learning about it more of course, also uh bit dot lee slash, try demo is the other way to do that.

A

B

A

B

A

In bit, dot least, I should try demo and it'll, bring you right to this page as well. So anyway, we're gonna hop over now to demo on sawtooth. This is actually built.

B

By one of our integration partners.

A

Blockchain partners is what they're called and yeah so.

B

They've made this and a few other of them.

A

B

A

And yeah it's really cool so.

B

Now we're gonna don't think I need to.

A

Run that build stuff. Actually, let me skip that for a second and see.

B

um So what you would normally do, though, is you would go run the build dock get docker installed. If you didn't, have it get clone everything and wait a few minutes for the project to.

A

B

Goswami is asking for github links to the different demos worth of uh demoing. Yes, absolutely.

A

Let me actually share some of those so share those in chat right now,.

A

And this is that one sawtooth.

A

And this is my overview repository.

A

And probably the most important of all is demo itself, so let me get you the link to that.

A

And yeah, so you can go um work through.

B

There and check that out one other thing, though, if you're, if you're interested in all this, is to actually go to demo.com, learn and there you can actually go and run a lot of these things just within your web browser to just kind of try them out and get a feel for them.

A

Obviously we love people installing and trying demo.

B

On their their local computers, but if, like the first thing you might want to do, is you can go and try out deploying download production ledgers, and this will go ahead and run through where you can actually deploy that same application? So you could, for example, go and say: oh, I want to try it doing downhill on.

A

B

You can start that scenario and basically you can click all these commands in order to run an application and build it all in your web browser. This.

A

Runs on uh in the cloud on on other instances of the linux box, so.

B

Yeah, that's another option for that. You can go.

A

To just donald.com.

B

But of course, once you want to really get started dive into it, definitely install the demo, the demo sdk and then go ahead and try these applications out, because, obviously there's there's nothing, there's no learning like doing it yourself.

A

B

First, I'm going to try, I might have to build this project again, so it might take a moment.

A

um But hopefully I don't and we're going to do. Docker slash run, let's start yep. So I need to build this again because I deleted all my docker containers. I probably shouldn't have done that.

A

So we're going to run that because I already have docker and everything installed and then we're going to run build.sh and hopefully uh that's going to.

B

Complete within the next few minutes, so that I can.

A

Finish showing the rest of this, but.

B

While we're doing that, I mean we have plenty of other things. We can kind of look at so.

A

Over here, if I come back to to my.

B

Little page here uh installing demo itself.

A

It's pretty easy, you can just uh it does, have a java dependency. So sometimes that can hang people up on occasion, um but we do have some some instructions here for managing that. uh If you're on windows 10, you have an installer that you can run and if you're on mac or linux, you can run this command locally and that'll go ahead and install install uh demo automatically. There is also a manual download.

A

So if you want to verify everything or do some sort of uh non non right, non-standard install, you can go ahead and follow the instructions for manually install, and so there's that, uh like I said, devil.com slash, learn is a great place to try things out for the first time. uh Docs.Demo.Com is a great place to really learn, download and dive into it. So we have the getting started guide. uh We were just there at installing the sdk building your first application, adding some features to it.

A

We have that, uh then we have writing demo, and um this is mostly, I believe, written by bernhard, who runs a lot of our demo product site uh and he's just produced a great guide on really learning demo and really understanding it. And then we also have language references too, so you can dive into that and a whole bunch of documentation on everything else related to demo uh yeah. We also have our youtube channel, where you can see recordings of this video, which will be up shortly after and a variety of other ones we have.

A

You know we have tech examples, and we also have things where we explain uh different verticals and different use cases where that model is being used and where it's beneficial and yeah, then we have a bunch of other other things too discussed tamil.com uh the certification, demo.com certification, where, if you wanted to get certified in dental, you could check that out and then down here. The demo associate exam is the one that I'll be giving away for free uh at the end. Well, I can actually kind of just show you the code.

A

Now it's hl delhi. So if you were to go to devil.com, slash certification, uh you could like purchase the exam, but then on the following screens, when you're actually entering it, there'll be a section for a coupon code, so just enter hl delhi in there and you'll get 100 off. This is limited to the first 20 people that take it. So if you are interested go ahead and take it ahead of time, even if you're just a little bit interested and then if you decide you're.

B

Going to learn demo and later want to go through.

A

The certifications and kind of test, your skills- you can go ahead and do that and that has a question here: is it possible to migrate existing uh go chain code to.

B

Download already written is.

A

You already know how your application is going to work and that's a major benefit, um just in general, obviously with any application, but with demo you'll be able to say. Oh all, these concerns I had and all these different parties that I know about that. I want to work with. That's actually really easy to transform into demo code yourself, but unfortunately you know we don't have a layer to translate it. We even do have. There are some blogs.

A

There are blogs that go into uh kind of comparing demo code to others. There was one I don't think it was go, but it might have been kotlin or something on corner where there was translating between it, and so there there are blogs on it. um I'm just not sure I'm gonna do it I'll actually follow up with you on that and send send it out after this.

A

So now harsh has a question hi. I was using demo and went through the demo design pattern. So I wanted to know whether you were trying to achieve plugable consensus using those patterns as they enable to write transactions to different ledgers only after certain signatures and those transactions only those signatures that we have defined.

A

uh Yes, so basically, it's not particularly consensus in the sense of the network, achieving consensus for that. We leave it to the node.

B

um But when it comes to different.

A

Parties having to consent amongst themselves um like consents versus consensus,.

B

Yes, that part is something that we want to be very explicit about, and so the only way to write certain transactions to ledgers is to make sure that all the signatures that they require are present on those transactions.

A

So hopefully that answers your question. That's a great question, though. Yes, so thank.

B

A

A

So it is two-way consensus, two times consensus, one at the court level and one at the ledger level. If we deploy, in suppose say, fabric.

B

Yes, that's correct, so you'll basically have at the ledger level is you're, making sure that different parties are consenting to the contracts that they are parts of and then at the fabric level.

B

uh That's actually achieving the network-wide consensus of these are the valid transactions that uh happened when and where and in the order that they happen so fabric's doing the ordering as well.

A

Every everything that fabric does.

B

And anil's answering asking a question here, so I write once and can have sawtooth beers.

A

And hf beers, but those solar toothbrushes stay in the sawtooth world and hf beer stain.

B

uh Yes, so it depends so, like I had mentioned.

A

um There is, let me just fill that really quick too.

B

There is uh canton.io- and this is our synchronization protocol- that we're developing, where it's going to enable you to uh not worry about that world and actually get interoperability. So right now, with the demo applications that I'm demoing and deploying yes, that's true, but if you use canton uh your sawtooth and your fabric, uh beers can actually cross chat uh if you were to deploy it using canton instead, and so you would still have the same demo code. But you would then have this additional layer that allows for that interoperability and that's a really.

A

B

Cool part of demo, that's still being worked on and that's just at canton.io. If you want to check that out, uh there's a bunch of documentation on it and you can even go ahead and you know download it. um I've also seen some interest from other times I've. Given this talk, so I think we're probably going to eventually do a talk on canton as well. Hopefully, if, if everybody's amenable to that, but that's something, we could always always chat about more in depth.

A

But yeah anyway, um so now I have.

A

B

Okay, so now I've got download.

A

Sawtooth built so we've built it in time and answered a bunch of more different questions at the same time, and now what I'm going to do is I'm going to start it up so right here.

A

B

Interested in learning about canton, so I think we'll definitely do.

A

Something in the future on.

A

A

Cool and yeah so right now our sawtooth ledger is starting up and it's going.

B

To start up not only sawtooth itself, but also the downward driver you'll, see uh in a moment, you'll see rpc going by and that's the demo driver, so you could actually start them up separately, like we did in fabric. It's just that this little shell script that helps that out uh doesn't have that going on.

A

So the rpc starting up and should be running in a second. So I'm gonna just hop back over to here and.

B

Yeah, okay, so we've started and we're running now on port 9000, so it is slightly different, and so what I'm going to do is I'm not going to build the code again. I would actually like to show you this without truly building the code again, but demo deploy rebuilds it. You can just trust me that this code over here has not changed in any way to be special to sawtooth, but I'm going to go ahead and deploy this code now to port 9000.

A

And you'll see just as before, we'll start committing transactions, hopefully not the way. That's not responding.

A

That should definitely be working, but that's the fun of uh of live demos. Let me cancel that quickly.

A

I guess maybe this wasn't fully up.

A

I seem to have hit some awkward time out. Okay,.

B

uh I'm not sure what what I did wrong here.

A

Probably does something wrong um yeah anyway, uh if you watch you can.

B

Go to youtube.com driven, maybe something's changed since I last built this and I need to file a bug report, but uh you can actually see that over.

A

B

I do have videos up of this talk previously, where we would have deployed uh damon sawtooth but yeah. So that's that's the presentation ending ending on a on a high note there, and if anybody else has any other questions you know you can feel free to ask me: um you can head over to bit dot lee slash, try, dental and through there you can go and see all the links and get to the forum and ask questions and.

A

You know report blogs if you, if you encounter them like I I've just done, but.

B

Yeah, thank you very much and thank you all for asking the great great questions. I have a couple minutes left. If you have any more, but if not, then I can give you a few minutes.

A

Back awesome, I'm glad you've all found it very useful. uh All right, I'm gonna stop sharing them and yeah. This is.