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Rob Tweed · May 24, 2016 go to post

Native Mobile Cache-based app development is now possible in JavaScript using React Native and EWD 3.  For instructions, see https://groups.google.com/forum/#!topic/enterprise-web-developer-commun…

The benefits are huge: just one language (JavaScript) for front-end and back-end app development on all platforms, one development pattern for front-end UI development on both desktop and mobile platforms, and the opportunity to re-use the same back-end logic for desktop and mobile apps.  

Additionally, just like desktop browser-based apps, with EWD 3 and React Native, Mobile apps can use WebSockets instead of REST to access the back-end and Cache.

Rob Tweed · May 29, 2016 go to post

1) ewd-document-store is primarily designed for use by the JavaScript developer who wants to use / access a Cache database without needing to learn or use COS, or for anyone wanting to migrate their logic to JavaScript whilst retaining Cache as a database.

2) it works with any version of Cache that supports the cache.node interface (at least 2012.x onwards)

3) It can be used against existing/legacy  global storage as well as new storage.

4) It's free Open Source (Apache 2 licensed)

Read the documentation for more information.

Rob Tweed · Jun 10, 2016 go to post

Benjamin

In my opinion, your questions are important: I'd summarise them as follows:

- is this new Document model an attempt to bring Cache to the attention of a new audience and marketplace, or is it really just targeted at the incumbent user-base as a means of persuading them not to migrate to competing Document databases such as MongoDB?

I'd like to think and hope it's the former rather than the latter.  

Many of you will be aware that I (and George James) have been championing the cause for Cache as a universal NoSQL database since as along ago as 2010, in fact very soon after the whole NoSQL movement burst on the scene in late 2009.  We saw this as a great opportunity to raise the profile of Cache.  I'm pretty disappointed that 6 years later, I'm yet to come across anyone I meet in the IT mainstream who has heard of Cache, despite its powerful NoSQL capabilities.

There are a number of reasons why we're still in this position of obscurity, but what has become clear to me in the intervening years is that there's one really key stumbling block: almost nobody out there wants to have to learn a new and obscure (and many would say antiquated) language in order to access a database, no matter how powerful and flexible that database.  

If the objective is to bring Cache to the attention of that new NoSQL-focused audience, it's become clear to me that all its database capabilities have to be accessible via the language(s) that people already use.  Since it's also clear to me that the major language adopted by the NoSQL marketplace is JavaScript, then it makes sense that JavaScript must become a first-class language for Cache if it's to stand any chance of the wider recognition it deserves in the NoSQL world.  

Unless the new Document database capabilities of Cache are available directly from JavaScript, unfortunately my conclusion is that its only real audience is the incumbent user-base who are happy to continue using Cache ObjectScript and Cache's built-in programming environment.

See my recent posting on EWD 3 for my approach: my target audience is the JavaScript developer in search of something rather more interesting and powerful than the usual NoSQL databases, not the incumbent COS-oriented developer, who may not see the point in EWD 3, Document databases and all this JavaScript stuff!

There's a massive opportunity out there, but nearly 7 years since the NoSQL party began and 5 years since the JavaScript party began, I worry that the new Document database capability is too little, too late to be invited to either.

Rob Tweed · Jun 23, 2016 go to post

If you're anything like me, you'll want to try out all this Node.js and EWD 3 stuff on a separate throwaway Virtual Machine or EC2 instance.  If so, take a look at this "installer" file that I've created:

https://github.com/robtweed/ewd-3-installers/blob/master/ewd-xpress/install_cache.sh

It's designed for use with a new "virgin" Ubuntu machine/virtual machine.  It's not really an installer script as such - there are a few steps that, by necessity, would have to be done manually, but you may find it a helpful set of steps to cut and paste into a terminal window, or to adapt for your own use into a proper installer.  I've added comments in all the places you'd need to do something manually or modify the script.

Anyone familiar with other flavours of Linux should be able to adapt it.

What will it do? It contains the instructions you need to:

  • install and configure a copy of Cache (it assumes you've downloaded the install kit)
  • install Node.js
  • Install ewd-xpress (plus its dependencies) and configure it ready for use

Hopefully this "script" will allow you to get a system up and running to play about with in just a few minutes.

Rob Tweed · Aug 3, 2016 go to post

With Node.js versions coming in thick and fast, the question: "where do I get the appropriate version of cache.node?" is increasingly a problem for people who want to use Cache with Node.js.  

Bundling the latest versions of cache.node with build kits for the latest versions of Cache makes little sense - people need to use Node.js with whatever version of Cache they currently have installed and use.  If they update Node.js (which, as I say, is a frequent requirement these days), they won't want or expect to update Cache too.  So currently you have to download a Cache kit and install it on some temporary machine just to extract the latest cache.node files.

Instead, can I request that the cache.node kits are distributed separately in a location that users can know to look for?

Anyone else agree?

Rob

Rob Tweed · Sep 9, 2016 go to post

Yep, self-fullfilling prophecies have a knack of failing, Timur :-)

Rob Tweed · Sep 9, 2016 go to post

I assume that as part of the initiative to enter the IoT marketplace, an ARM port of Cache is on the cards anyway?

if so, it might as well also run on the Raspberry Pi!

Needless to say, people are wanting to use databases, for all sorts of reasons, on the RPi - eg https://www.raspberrypi.org/forums/viewtopic.php?f=34&t=142506

and of course, they're ending up using the other usual databases that have made the investment to port to it.  So the RPi community remains unaware of what Cache could potentially do for them instead.

Seems like a missed opportunity to me, but there you go.

Rob Tweed · Sep 10, 2016 go to post

Probably so, Herman - that's why I always hoped for the much more lightweight GlobalsDB to be ported to ARM. 

Rob Tweed · Sep 12, 2016 go to post

IMO that's a depressingly risk-averse approach.  The whole point of the IoT area and the Raspberry Pi is that it's still largely unexplored "solution looking for a problem" territory, where people try novel ideas out because they can and because it's cheap and easy to do so.  Sure, you can wait until the market-place is clearly defined and then provide your own "we can do that too" option (and effectively miss the boat as a result), or you can be truly innovative and put it out there and see what happens, potentially catalysing ideas as a result of it being there.  

That's been my philosophy for the last 20 years - if I'd been waiting for people to give me use cases, I'd not have developed a thing in all that time.

Rob Tweed · Sep 21, 2016 go to post

The very much more elegant forEach construct is precisely what the EWD 3 ewd-document-store JavaScript abstraction of Global storage provides you with.  See:

http://www.slideshare.net/robtweed/ewd-3-training-course-part-22-traversing-documents-using-documentnode-objects

For traversal within ranges, see:

http://www.slideshare.net/robtweed/ewd-3-training-course-part-23-traversing-a-range-using-documentnode-objects

See also:

https://github.com/robtweed/ewd-document-store

Rob

Rob Tweed · Oct 12, 2016 go to post

You could go a further step and run a JavaScript-based terminal console in a browser and hooking it up to Cache via Node.js.

See https://robtweed.wordpress.com/2014/03/03/ewd-js-and-vista-adding-a-jav… for an example implementation

These days, you could use something like Electron to create what appears to be a Windows application, but in fact is a packaged up Chrome & Node.js environment.  In fact, IMO, this is how Atelier should have been implemented.

Remember that as soon as you have something such as this running in a browser, security (ie who has / hasn't access to the application running in the browser) becomes a major issue - you're giving command-line access to your Cache database!

Rob Tweed · Apr 21, 2017 go to post

Chris Munt would be the person to ask, but I'm not aware that the lack of a resolution to the bottleneck issue is anything to with security - more that Google don't "get" the issue and see it as a priority, since it's an unusual requirement.

Anyway cache.node is an official InterSystems interface so why not just use it instead of rolling your own?  Ideally ISC should be pushing Google to fix the bottleneck.

Rob Tweed · Apr 26, 2017 go to post

Regarding the installation of QEWD, it's worth pointing out that the Github/NPM repository includes an installers folder which contains a number of installer scripts for Linux-based systems. There's even one for QEWD + Linux + Cache, although it shouldn't be run as a script since you will probably already have Cache installed - use it instead as a guide for the commands you need to run in order to install the various bits and pieces.

See https://github.com/robtweed/qewd/tree/master/installers

There's even an installer for the Raspberry Pi, although that can't use Cache (sadly!)

Another alternative is to use the Docker appliance, but it would need to be adapted to work with Cache.  See https://github.com/robtweed/qewd/tree/master/docker

Rob Tweed · May 1, 2017 go to post

Yes - there is no actual endpoint at /api, hence the error response.

Try one of the unauthenticated endpoints that is documented in the RealWorld Conduit API document, such as /api/tags and you'll get a proper response

Rob

Rob Tweed · May 1, 2017 go to post

Yes - qewd-conduit is a pure REST back-end.  As such it has no front-end markup (though it could).  The /api endpoint does not, in itself, have any meaning - it's just the root URL for all the valid Conduit endpoints, eg GET /api/tags

qewd-conduit returns JSON responses, not HTML