Couchnode, the Couchbase Client Library for Node.js, is a native module. The tool used to install native modules is node-gyp. So to install couchnode you need to install :
GYP uses Python to generate the project, so you need to install it on your environment. I have installed Python 2.7.3 using the Windows installer.
Install Visual Studio
Finally you need a C/C++ compiler, the best way to get it is to install Visual Studio. As you probably know I am not a Windows expert and I do not know a lot about Microsoft development tools. I have downloaded Visual Studio Express the free development tools from here; it was sufficient.
Install Libcouchbase for Windows
Couchnode uses libcouchbase the C client library, so before running the npm install for Couchbase, you need to install libcouchbase itself.
You can download it from Couchbase site. The Windows versions are located in the left menu of the page. Download the zip file, that matches your environment. I have downloaded the "Windows, 64-bit MSVC 10".
Node-gyp will look for all the dependencies (DLL, library headers) into c:\couchbase directory, so you need to unzip the file in this folder. This location comes from the binding.gyp file of the couchnode project.
Install and Test Couchnode itself!
Let's check what we have done so far; we have installed:
Node
node-gyp
Python
Visual Studio
Libcouchbase
We are now ready to install and use couchnode itself. For this we can create a new node project.
mkdir my-appcd my-appnpm install couchbase
The install command will:
Create a node_modules folder and put couchbase client library in it
When installing/building couchnode on Windows I had the following warning :
C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V110\Microsoft.CppBuild.targets(1138,5): warning MSB8012: TargetExt(.dll) does not match the Linker's Output
File property value (.node). This may cause your project to build incorrectly.
To correct this, please make sure that $(OutDir), $(TargetName) and $(TargetExt) property values match the value specified in %(Link.OutputFile).
[C:\Users\tgrall\node\node_modules\couchbase\build\couchbase_impl.vcxproj]
This is only a warning and as far as I know, it is not a blocker. At the end of the log you should see:
When you are developing a new applications with Couchbase 2.0, you sometimes need to create view dynamically from your code. For example you may need this when you are installing your application, writing some test, or you can also use that when you are building frameworks, and wants to dynamically create views to query data. This post shows how to do it.
The first thing to do when you want to create a view from Java is obviously to connect to the cluster.
import com.couchbase.client.CouchbaseClient;...List<uri> uris = new LinkedList<uri>();uris.add(URI.create("http://127.0.0.1:8091/pools"));CouchbaseClient client = null;try { client = new CouchbaseClient(uris, "beer-sample", ""); // put your code here client.shutdown(); } catch (Exception e) { System.err.println("Error connecting to Couchbase: " + e.getMessage()); System.exit(0); }...
Create a list of URIs to different nodes of the cluster - lines 5-6. (In this example I am working on a single node)
Connect to the bucket, in our case beer-sample -line 9. You can include the password if the bucket is protected ( this is not the case here so I am sending an empty string)
If you are looking for more information about Couchbase and Java, you can read this article from DZone : Hello World with Couchbase and Java.
Let's now talk about Couchbase views. You use views/map-reduce functions to index and query data from Couchbase Server based on the content of the JSON document you store inside Couchbase. For more information about views you can look at the "view basics" chapter of the Couchbase Server Manual.
Creating a view from Java is really easy : the Java Client Library contains all the classes and methods to do it. As a concrete use case we will use the Application that is described in the Couchbase Java Tutorial.
When you follow this tutorial, you need to manually create some views, as you can see here. In this example, we will create our map function and directly in our Java code and then store it to Couchbase Server. The tutorial asks you to create the following artifacts:
a view named "by_name"
in the design document named "dev_beer" (development mode)
and the map function which looks like the following :
Create a design document using the com.couchbase.client.protocol.views.DesignDocument class - line 4.
Create a view using com.couchbase.client.protocol.views.ViewDesign class with a name and the map function - line 14.
You can add this view to a design document - line 15
Finally save the document into the cluster using the CouchbaseClient.createDesignDoc method.
If you need to use a reduce function (built-in or custom) you just need to pass to the ViewDesign constructor as 3rd parameter.
When developing view, from Java or from any other tool/language be sure you understand what are the best practices, and the life cycle of the index. This is why I am inviting you to take a look to the following chapters in the Couchbase documentation:
View Writing Best Practice : for example in the map function, I do not emit any value. I only emit a key (the beer name).
Development and Production Views : in the view above, I have created the view in the development environment (dev_ prefix) allowing me to test and use it on a subset of the data (cluster/index)
First of all, the view that you just created is in "development mode", and by default the Java client SDK will only access the view when it is in "production mode". This means that when you are calling a view from your application it will search it into the production environment. So before connecting to Couchbase cluster you need to setup the viewmode to development.
This is done using the viewmode environment variable from the Java SDK, that could be set using the following methods:
In your code, add this line before the client connects to the cluster : System.setProperty("viewmode", "development");
At the command line -Dviewmode=development
In a properties file viewmode=development
Once it is done you can call the view using the following code:
import import com.couchbase.client.protocol.views.*;...System.setProperty("viewmode", "development"); // before the connection to Couchbase...View view = client.getView("beer", "by_name");Query query = new Query();query.setIncludeDocs(true).setLimit(20);query.setStale( Stale.FALSE );ViewResponse result = client.query(view, query);for(ViewRow row : result) { row.getDocument(); // deal with the document/data}...
This code queries the view you just created. This means Couchbase Server will generate an index based on your map function, will query the server for results. In this case, we specifically want to set a limit of 20 results and also get the most current results by setting Stale.FALSE.
Set the viewmode to development - line 4
Get the view using the CouchbaseClient.getView() method -line 6-. As you can see I just use the name beer for the design document (and not dev_beer, Couchbase will know where to search since I am in development mode)
Create a query and set a limit (20) and ask the SDK to return the document itself
setIncludeDocs(true) -line 8- The document will be returned from Couchbase server in the most efficient way
Ask the system to update the index before returning the result using query.setStale( Stale.FALSE ); -line 9-. Once again be careful when you use setStale method. Just to be sure here is the documentation about it : Index Updates and the stale Parameter
Configure development/production mode views from Couchbase Java Client Library
This example is limited to the creation of a view, you can take a look to the other methods related to design documents and views if you want to manage your design documents : getDesignDocument(), deleteDesignDocument(), ...
Working with the Couchbase 2.0.0 release you may have issues when trying to access the Web Admin Console or simply starting the server. This is due to the way Couchbase Server uses the IP address/hostname during the installation process. So when you have one of the following errors :
On Windows, Server is not working at all, even after installation. You can access the sever on port 8092 (Couchbase API port), but cannot on port 8091
You have the following error when accessing the console "[10:02:02] IP address seems to have changed. Unable to listen on 'ns_1@10.0.2.15'"
When you try to restart the server it does not start and you have the following error message in the error log :
"Configured address '10.0.2.15' seems to be invalid. Will refuse to start for safety reasons"
Some of these issues are related to a known issue on Windows ( see MB-7417 that will be fixed in 2.0.1) or the fact that Couchbase server does not support change of the IP address after installation. This is documented in the section “Using Couchbase in the Cloud: Handling Changes in IP Addresses” of the Couchbase Server Manual. This article explains what should be done when configuring Couchbase Server on Windows, but you can do equivalent steps on any platform using the shell scripts available on Linux and/or Mac OS X.
Once you have installed Couchbase, you can see in the console that the IP address of your server is used :
Typically the address 192.168.0.97 is stored in the configuration of Couchbase. If your server receives a new address from the DHCP server, Couchbase will not work anymore. In this article you will see how you can configure Couchbase to use another IP address or Hostname.
Important: The steps that follow will completely destroy any data and configuration from the node, so it is best to start with a fresh Couchbase install. If you can not, you should backup your data using the file based backup-restore documented here.
Yesterday was my last day at eXo... I have been working at eXo since 2008, and we have achieved many exciting things such as building eXo Platform, the open source social platform, and the Cloud-IDE allowing developers to build, test, and deploy applications online.
It was a great experience for me, but it is time for me to jump into a new adventure...
I am joining Couchbase as a Technical Evangelist for the EMEA Region. When I have started to work with NoSQL engines (starting with Google BigTable for Resultri) I really enjoyed the experience and the flexibility that it gives to the developers. Then I choose to work on a documented oriented database because it looks very natural to me, and evaluate the clustering capabilities. This is how I discovered Couchbase and its community.
This new job is a great opportunity for me to do the things that I really like about software:
Coding applications using different languages and frameworks
Understanding the sysops/devops related challenges when using a new product/technology
And finally probably the most important part; sharing it with others!
I look forward to sharing what I like about NoSQL and Couchbase and discuss with others about their experience or needs around NoSQL.Â
See you soon online and in real life during conferences and meetups!
In this example I am using Java to inject Tweets into Couchbase, you can obviously use another langage if you want to.
The sources of this project are available on my Github repository Twitter Injector for Couchbase you can also download the Binary version here, and execute the application from the command line, see Run The Application paragraph. Do not forget to create your Twitter oAuth keys (see next paragraph)
The first thing to do to be able to use the Twitter API is to create a set of keys. If you want to learn more about all these keys/tokens take a look to the oAuth protocol : http://oauth.net/
The following code is the main code of the application:
Some basic explanation:
The setUp() method simply reads the twitter4j.properties file from the classpath to build the Couchbase connection string.
The injectTweets opens the Couchbase connection -line 76- and calls the TwitterStream API.
A Listener is created and will receive all the onStatus(Status status) from Twitter. The most important method is onStatus() that receive the message and save it into Couchbase.
One interesting thing : since Couchbase is a JSON Document database it allows your to just take the JSON String and save it directly. cbClient.add(idStr,0 ,twitterMessage);
NOTE: The Couchbase Node.js Client Library is currently changing. I will update this article and source code once the API is stable.
I am currently playing a little bit with Node.js . It is quite fun! In this article I won't go in a a very complex application but just give you the basic steps to create your first Node.js+Couchbase application... on Mac OS X.
In this post I just want to show how easily is to get
started with Couchbase, and also explain how to “query” the data. The basic
steps of this tutorial are:
Install Couchbase
Create Data
Query Data
I will try to post more articles, if I have time to show how to use Couchbase from your applications (starting with Java).
Prerequisites :
Could not be simpler : Couchbase 2.0 available here. (Currently in Developer Preview)
I am using Couchbase on Mac OS X, so let me describe the installation in this environment. If you are using other operating system just take a look to the Couchbase documentation.
Couchbase installation is very (very!) fast:
Download the Mac OS X Zip file.
Double-click the downloaded Zip installation file to extract the contents. This will create a single file, the Couchbase.app application.
Drag and Drop the Couchbase.app to your chosen installation folder, such as the system Applications folder.
To start Couchbase Server, just double click on the Couchbase Server. Once the server is started, a new icon is added in the OS X Menu to indicate that the Server is up and running.
You can now configure your Couchbase instance, for this you just need to access the Admin Console, available at the following location http://127.0.0.1:8091 (change the IP address if needed) or simply by going in the Couchbase menu and click on Open Admin Console entry.
Welcome Screen : Click Setup
Set the disk and cluster configuration. On my instance I keep the default location for the on disk storage. Just configure the size of the memory usage for your instance, for example 800Mb. So far, we have a single instance, so no need to join a cluster.
Choose to generate sample data. This will be interesting to learn more about data and views.
Create the default bucket (use for testing only). A bucket is used by Couchbase to store data. It could be compared to a “database” in RDBMS world.
Configure update notifications to be alerted when new version of Couchbase is released
Configure the server with a final step with the administrator username and password
When this is done you are automatically redirected to the Admin Console.
This is it! You are ready to use your Couchbase server.
Couchbase has many interesting features, especially around scalability and elasticity but for not in this article let's focus on the basics :
Couchbase has many ways to manipulate data from you favorite programming language using the different client libraries : Java, Python, PHP, Ruby, .Net, C. For now let's use the Admin Console to create and query data.
Couchbase can store any type of data, but when you need to manipulate some data with a structure the best way is to use JSON Documents. So let's use the console and create documents.
To create new documents in your database, click on the "Data Buckets" tab. If you have installed the sample you see 2 buckets: default and gamesim-sample.
Let's create a new documents in the default bucket:
Click on Documents button
Click on Create Document
Since each document must have an id for example 100.
Couchbase save the document and add some metadata such as _rev, $flags, expiration
Add new attributes to the document that describe an employee : Name, Departement and Salary, then save it. You just need to update the JSON object with values
First of all you can quickly access a document using a simple HTTP request using its id. For example to access the Mayla with the id 300 just enter the following URL:
http://127.0.0.1:8092/default/300
In this URL you have :
8092 is the Couch API REST port used to access data (where 8091 is the port for the Admin console)
default is the bucket in which the document is stored
So we have seen how you can access one document. But what if my need is :
"Give me all the employee of the Technology department"
To achieve such query it is necessary to create views. The views are used by Couchbase server to index and search your data. A view is a Map function written in JavaScript, that will generate a key value list that is compliant with logic you put in the Map function. Note that this key,value is now indexed and sorted by key. This is important when you query your data.
So let's create a new view from the Admin Console:
Click on the Views tab (be sure you are on the default bucket)
Click on the "Create Development View"
Enter the Document and View name:
Document Name : _design/dev_dept
View Name : dept
Cick Save
Click on your View to edit it
Since we need to provide the list of employees that are part of a the Technology department, we need to create a view that use the department as key, so the map function looks like :
function(doc){emit(doc.dept,null);}
Save the view
This function takes the document and create a list that contains the "dept" as key and null as value. The value itself is not that important in our case. A simple rule will be : do not put too much data in the value since at the end Couchbase server creates an index with this map. Will see that Couchbase allows developer to easily get the document information when accessing a view.
Click on the "Show Results" button, the result will look like:
As we have seen in earlier it is possible to access the document using a single URL, it is the same for views. You can for example access the view we have just created using the following URL:
You have many other parameters you can use when accessing a view to control the size, the time out, .... One of them is quite interesting is include_docs that ask Couchbase to include the full content of the document in the result. So if you call :
Let's now create a little more complicated view to answer the following business requirement:
"Give me all the employee with a salary between 5000 and 6000"
So now you know that you need to create a new view with the salary as key let's with the following Map function:
function(doc){emit(doc.salary,null);}
Couchbase is automatically sorting the key when creating/updating the index so, let's use the startkey and endkey parameter when calling the view. So let's call the view with from the following URL:
Install Couchbase* Create data using the Admin Console
Query data with views
When I get more time I will write another article that do the same from Java, and other languages.
Note from @ingenthr
Nice blog! Note that while querying the REST interface directly is okay, we've really tried to make it easy by having high-level language support for queries in each of the official client libraries. They're all listed over at http://www.couchbase.com/develop
Like many developers I am using Twitter Boostrap for my Web applications. Using this framework has been very helpful for me, since I am really not a good HTML/CSS developer. For now, on my site Resultri I am using the default look and feel, will customize it later.
Lately, I wanted to integrate Google Map to my application, and when testing it, I had the bad surprise to see that the Controls and WindowInfo are not printed correctly as you can see in the screen shot below:
This is not a big issue at all, just a conflict on the img tag and its style (max-width) coming from Twitter Bootstrap. The quick fix :
override the style of the img tag for the div that contains your map.
For example in my case the div for my map is define as:
<divid="resultriMap"/>
You just need to add a new style to your page with the following definition:
<style>#resultriMap img{max-width: none;}</style>
After adding this to my page the map is correctly printed as you can see in the following screenshot :
Last week I was invited to present eXo Cloud IDE during the SAP Cloud Inside. This SAP Community event was a great opportunity to discuss about the cloud with an interesting point of view: the impact of the cloud for SAP customers (especially administrators and developers).
During this presentation I have introduced the eXo Cloud IDE, and I did a demonstration in which O have built and deployed applications : Open Social Gadgets, Ruby on Rails and Java/Spring, and explain how it could be extended to SAP business services.
Here the slides that I have used during this presentation:
