Neo4J User Defined Functions - How to deploy new functions? - neo4j

I'm learning Cypher since yesterday and I read about the user defined functions.
There's many material on how to use the functions, but not many on how to deploy new ones.
I would like to try out but I'm having a hard time on finding a step-by-step tutorial on how to deploy new functions to my desktop app.
The ones I have found bypass some concepts as they were too obvious. And maybe they are for someone coming from a Java background or whatever the background is you're supposed to have when using Neo4J. ...But I come from a Javascript background. I'm used to npm, never heard of maven (just an example).
It would be nice you someone could help with a detailed step-by-step tutorial on how to write and deploy a new user defined function in Neo4J.

For helping a bit.
User defined functions are only writables in Java code for now. They're server extensions. You write the code with a Java editor (outside Neo4j) and publish it under a Java Archive (a file with extension .jar) into the /plugins directory of your Neo4j installation (https://neo4j.com/docs/developer-manual/current/extending-neo4j/cypher-functions/).
Many useful procedures already exist with APOC extension (https://neo4j-contrib.github.io/neo4j-apoc-procedures/) depending of your Neo4j server version.
Try them first bfeore developping yours, especially if you're starting with CYPHER. Some of them should solve your usuals demands.
All of extensions are taking effect after a restart of Neo4j.
Note : Maven is a dependency manager for Java.

Related

How do I package a rails as a standalone executable

I've been developing a web application and a lot of customers are asking if they can host the application in their network (for security reasons). I have been looking for a way to package up a rails app into a single executable (with server and all), but haven't been able to find anything. My other requirement is that we distribute it without the source. Because of that I was looking at JRuby and Warbler. The end product should run on linux or windows. Has anyone done anything like this before, or can anyone point me in the right direction.
Thanks
My best guess would be to use JRuby and the JRubyCompiler, although I have no idea if you could compile a whole rails project (including all the required gems). I got it to compile a small ruby script though. Anyway, if you succeed, you could package those in a jar or war and deploy that as a contained application.
It doesn't sound like you necessarily need to package it as an executable, as long as the code is obfuscated. I personally haven't needed to protect any of my code, but a quick google search returned this product http://rubyencoder.com/. I'm sure there are others out there, but the basic idea is that your code is unreadable and cannot be reverse engineered. This would allow you to run a standard rails environment without giving access to your source code.
If you have the budget and really want to outsource this, the Github guys partnered with BitRock to build their cross-platform installable product (Github Firewall Install). BitRock has this case study on their website.

Organizing, Storing, and Keeping Track of code for reuse

Many moons ago I started storing my music as MP3’s. I downloaded like mad and just dumped them all into a folder. After collecting thousands of songs I had a big mess. After two years of organizing all music in my free time I have made it to “D” section of my library. I am starting to write code on a daily basis and I would like to keep a lot of what I do for reuse and future reference. I use Visual Studio a lot, and Eclipse sometimes, but I also do web development. Right now I am just have a folder on an external drive called Projects and inside that folder I have code I want to save broken down by its respective IDE and then the language it was developed in. This is working ok right now, but I fear after a few years it might get hard to navigate, and I don’t want another mess like my music library. What are some good ways to keep track of code and programming projects while also promoting easy navigation and future reuse?
I use a subversion repository for purpose of saving code for the future. In my repository I have the following folder structure:
\
|- Project1\
|- - Trunk\
|- - Branches\
|- - Tags\
|- Project2\
....
This is working for me and I have big and small projects that I coded on since high school in this repository. If I for instance want to port a project that I coded on Linux to Windows I create a branch that I for example call Win32-port. And when I have a 1.0 release of a project I create a tag named 1.0.
Using this method you can also set up back-up scripts and save a backup to another location. (I use a cron job and some python scripts to achieve this, but it all depends on what system the server uses.)
A book about subversion are freely available here: Link
For Mac OS X, there's the beautiful Snippets:
(source: snippetsapp.com)
Also, the new Xcode 4 will have native support for custom code snippets.
It won't really solve your organising problem, but you'll be more productive anyway by using snippet be it inside Eclipse or inside Visual Studio.
Here's a short tutorial for snippet in Eclipse : http://www.dansshorts.com/post/creating-snippets-in-eclipse
And here the explanation to create them and link them to a keyword in Visual Studio 2010 : http://www.visualstudiotutor.com/2010/02/create-snippet-visual-studio-2010/
This would take a bit more infrastructure to set up and is more for multiple people working together, but the best approach is to start thinking of Software as a Service.
For commonly used functions, wrap them as a web service with good documentation. For instance, if you have a phone validator that seems to be constantly used across projects, it would become part of your validator service.
With few exceptions, most shops don't seem to organize/share code effectively with static document type code libraries.
This would also force you to refactor the code snippets into reusable methods instead of just random code that is copied/pasted in. It also gives you a clean seperation between the public interface and private implementation.

Grails startup is slow

Help! I'm porting a large ruby app to Grails - but the Grails startup of my application takes more than 2 minutes.
I've already set dbCreate to "read" I've ensured my high end dual processor desktop windows box gives Grails needed RAM (1 Gig). I have no plugins installed. I have 170 domain classes that used to be ruby classes.
When it starts up it prints out the line "Running Grails App.." and then hangs for a long time before it then prints out the "Server running" line.
I just did something where I migrated all my ids to bigints. That seems to have worsened the problem. Now it takes about 10 minutes to startup.
I am new to grails would you please give me a few more details on what and where to log the events at startup? As to profiling the vm, its been a few years since I did a lot of Java. What do you recommend as the best profiling tool to use now?
What else can I do to speed up Grails startup?
Unfortunately, I am not sure too much can be done beyond what you already did. As you know, there is a lot going on when it starts up, with all the plugin resolution / loading, adding dynamic methods to your domain objects, and overall dynamic nature of Groovy.
I am not sure which version you are using, but I've asked for ability to turn off dependency checking when you start up in 1.2, since that adds a bunch of time to startup time as well.
I realize above isn't too helpful, so perhaps this will be: I split up my application into several plugins. One for domain objects, one for graphing capability, one for excel import, another for some UI constructs I needed. I didn't do it just because of slow startup times, but the advantage is that I can test parts of the system separately from each other before integrating everything together.
I am about to add a piece of new functionality that involves at least 10 new domain objects, and I am first developing them in a separate plugin by having stubs for the few objects they have to interact with from the core app. That allows me to both reduce startup times, and also have my code better isolated.
So if it's an option for you, try to separate out things so you can work on them separately, which will alleviate your issue somewhat. There may also be other benefits in terms of having your team work on smaller components separately, better modularization, etc.
Hope this is helpful.
170 domain classes is fairly large, but 2 minutes still seems really long to me. Do you have a ton of plugins installed? Potentially too verbose debug settings?
I'd be curious how long it took if you created a fresh grails app, copied in all of your domain objects (and the subset of plugins that the domain objects might need to actually operate) and see how long that takes to start.
Jean's suggestion about separating things out if possible is a good one. I've done something similar on previous projects where we have a domain plugin, and our other apps all rely on that domain plugin.
You could also use the grails events to log some timing information on start up to see where your bottlenecks are. Timing the "PluginInstalled" event should be good as I think that the hibernate plugin would be caught by this in addition to the other plugins.
You may have a dependency problem. If a plugin you use relies on a library in maven that has 'open ended' dependencies, grails will go and look each time if there are newer versions to download in the range. I have no idea why anyone would specify it like this. It seems it would lead to unreliable behaviour. For me, the culprit is Amazon's java aws library, naturally used by a plugin that talks to Amazon's cloud.
http://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk/1.2.10
note how some of its dependencies are like this
org.apache.httpcomponents httpclient [4.1, 5.0)
it appears that every time, grails is looking for a newer version (and downloading if it exists, I just noticed 4.2-alpha1 of httpclient come down when I ran this time).
By removing that dependency from the plugin and manually adding the required libraries to my .lib folder, I reduced my startup time from >30sec to <1sec
You might want to see if there are other knobs you can turn other than Grails in order to fix this.
Have you tried approaching this as a performance issue? You can a look at the box performance and try to find out what the bottleneck is. Is it CPU? Is it a disk read issue? Can you attach a profiler to the VM and find out what's using up most of your startup time?
Have you tried basics like these for further deployment to a servlet container of your choice or in-place .war bootstrapping?
grails -Ddisable.auto.recompile=true run-app
grails run-war
grails war

Ruby on Rails plugin development process

I'm considering developing aspects of a website as Rails plugins for reuse. My question is about the development process. Since each of these plugins will provide a "slice" of functionality, should I develop each "slice" as it's own application and then extract the code from each application into a plugin? Or, should I write them as plugins right in an application? Ultimately I will be linking to these plugins from each site to keep it DRY.
I guess the main question is what would be the development process for creating multiple "Engine" type plugins?
Thanks in advance for any help.
Either approach is valid.
When writing a basic plugin I usually find it easier to write it in tandem with the application that will use it. Because I find it easier to design/test around something that already exists.
However, when it comes to Engine plugins, I prefer to develop them as a separate application and then rip out all the unnecessary bits when I move it into a plugin. They are in essence mini applications, and they should be completely functional when installed on a freshly created rails project.
By designing them as their own application I'm ensuring proper compartmentalization. This ensures that I'm not accidentally referring to code models/controllers/views/helpers that are not a part of the engine I'm developing.
If you're developing multiple engine type plugins this way, you might want to condense a few of the steps with a utility script. Such as one that streamlines the process of turning an application into an Engine plugin.
It should restructure your app as necessary and populate the files that plugins should have, such as init.rb.
You might want to give a look to Desert framework as well .

Source code search with Google Desktop

Is there a indexing plugin for GDS that allows for source code search? I see some for specific types (Java, C++, ...) and one for "any text". These are nice, but I would like one that allows for many/configurable extensions (HTML, CSS, JS, VB, C#, Java, Python, ...). A huge bonus would be to allow for syntax highlighting (http://pygments.org/) in the cache.
I just found Dropout and it seems to work great. Put Dropout in any folder and it will index all files in that folder. I put it in my Projects folder and it crawled all my code. Very fast and flexible search. Dropout
You could use OpenGrok or some other code-specific search engine instead.
I wrote a quick review of some of them some time ago.
It has been a long time, but the last time I tried to use Google Desktop Search for searching code, I found it quite inappropriate for that task, as I outlined at [http://perlmonks.org/?node_id=490310], the gist of which is that GDS (silently) only indexed a tiny fraction of many source code files (and made it quite a challenge to figure out why searching so often failed to find so much of what was in source code files).
I found Copernic Desktop Search worked better on code files (but I also had trouble with later versions of it being buggy in not finding all matches so I've been staying with version 2.1.1). But these days I don't use it much (mostly because I don't have permission to install such things on the laptop provided by my new employer).
You can try out Larry's Any Text File Indexer. You can specify a list of extensions at install time and it will do full text search on those file types.
Im just giving this a go:
http://desktop.google.com/plugins/i/java.html?hl=en
..also you can search for things in your Java tree using the following syntax in Google Desktop:
<YOUR SEARCH> filetype:java under:"C:\hft\trunk"
..where I keep my code in "C:\hft\trunk"
This is not a Google Desktop plugin, but works for what we need.
We have started using http://svnquery.tigris.org/ and it seems to work and is very fast. I wish it supported multiple repositories per site. We have a repository per project, so currently I have to create a virtual directory for each project we have. Not a show stopper, just something we need to automate in our project setup script.

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