|By Ignacio Coloma||
|March 29, 2005 12:00 AM EST||
Scripting languages have recently garnered a bit of attention. With the arrival of Groovy and Jython, writing scripts merged with Java is more natural than Ant. Using XML to call Java methods has always been forced, mostly because it's hard to express flow, conditional expressions, and custom Java code in a markup language (although things have improved a lot since Ant 1.5).
Why a scripting language? Well, if I have a completely blown IDE for Java programming, using Jython or Groovy can look backwards. You can code in fewer lines (though not much less), but I want the imports written automatically. I want compiler warnings while coding and I need refactorings. Plug-ins for these languages are still outside of Java IDE's capabilities.
But there are times where you just don't have a full IDE configured. Think about jobs that should be automated to be agile, or about server administrators. These people don't have anything like Eclipse, and their work can't be done in advance. You can't code for system administration. This is where tools like WLST come in and make the world a better place.
WLST (WebLogic Scripting Tool) is a Jython module that helps write scripts to administer and modify a server installation remotely. It comes in two flavors: offline, which can configure a server instance that doesn't exist yet, and online, which needs a WebLogic server to connect to. Both versions are in beta and are poorly documented, but they promise to improve and will be in some future WebLogic release.
We're going to focus on the online version here, because its functionalities are more complete than the offline version.
Automating Server Configuration:
Let's start by getting rid of that nasty WebLogic server configuration. Your typical development team replicates the same config in several hosts, changing only a couple of parameters such as the IP, hostname, and TCP port. In a relatively typical project, the process must be executed for each developer's PC, integration test host, and production. Ant tasks resolve great in this context, but it's not prepared to handle things like custom JMX beans.
We're going to create and launch the server, configure it, and do a shutdown, using a mixture of ant and WLST. First, let's create the server in Listing 1. For simplicity's sake, we're going to use the ant task here because combining WLST offline and online would mess things up.
I check the properties because when you deploy on more than one brand of app server it's easy to use the wrong build.properties file (see Listing 2).
We have just removed the whole domain directory, created a new clean one, and left the server running, so now in Listing 3 we can connect and configure it.
The server stop is necessary because some setting changes, i.e., security authenticators, need a graceful shutdown to be stored on disk. Omitting this step would kill the server in a hard way at the end of the ant script
Note: the WLST task is forked, and so, if WLST finds an error in your script, ant still will say "build successful," something that might confuse the person launching the script.
Let's split the WLST script into two parts to reuse as much of it as possible for administration tasks later. I have used the great examples enclosed with the WLST bundle and the output of the saveDomain() command as starting points. The saveDomain() generated script isn't very polished, but it serves to indicate the tool's possibilities (see Listing 4).
The loadProperties task converts all the entries in the administration.properties file to Jython variables. We've used the first methods of a Jython class to administrate the WebLogic server instance. It can easily be extended to create and remove DataSources, a JMS environment, and even security realms.
What you have seen is a way of creating and configuring MBeans (there's another way that will be explained in the next section). The downside is that you have to know the attributes and methods supported, and WLST doesn't document them. How can I guess which methods are available?
Well, the first way that comes to mind is going to the config.xml file or the web console and assume the attribute names hasn't changed. If we have a decent IDE we also can open the MBean interface class and see what's in there (it's the same as the MBean name, ending with 'MBean'). It won't show you code, but you can check which methods are available.
I prefer connecting to http://e-docs.bea.com/wls/docs81/javadocs/index.html and checking the contents of the package weblogic.management.configuration. For example, if we go to the ServerMBean class, we can see two interesting and not particularly well-known methods isJDBCLoggingEnabled() and setJDBCLoggingEnabled(). We can check them by opening the wlst interactive shell as laid out below:
wls:/mydomain/config> server=home.getAdminMBean('myserver', 'Server') wls:/mydomain/config> server.setJDBCLoggingEnabled(1) wls:/mydomain/config> server.isJDBCLoggingEnabled() 1
('home' is a variable of type AdminMbeanHomeImpl and can be studied as any other MBean; the only problem is that there's no javadoc available since it's an internal class).
If these last three commands aren't easily understood, don't worry. The shell will be covered in the next section.
Command Line System Administration
A system administrator can also administer the WebLogic server instance manually by using the interactive shell. The advantage here is you don't have to know a priori the MBean interfaces when trying to modify the system config. For this part, you have to include weblogic.jar, jython.jar, and wist.jar in the classpath and start the main class weblogic.WLST, which is the interactive console.
Keep it mind that this is Jython. Quotes and double quotes are used for string delimitation; instantiation doesn't need a new operator (as a matter of fact it's a syntax error); semicolons aren't required because each line ends with a carriage return; and variables don't have to be declared (a la Unix shell scripts). If that's not enough for you, please refer to the Python and WLST docs.
We need to start connecting to a WebLogic server instance. We can choose to use the AdminTool script developed before, or connect manually:
connect('weblogic', 'weblogic', "t3://localhost:7001) Connecting to weblogic server instance running at t3://127.0.0.1:7001 as username weblogic ...
Successfully connected to Admin Server 'myserver' that belongs to domain 'mydomain' is system output and should be formatted as code.
Now we can start playing with it. With WLST, the JMX tree can be traversed as a Unix filesystem, where the JMX MBeans are directories and its attributes are files. Keep in mind the Python syntax all the way through, and remember that WLST still doesn't recognize wildcards. That's the reason why we're going to omit most of the ls() output (see Listing 5).
We could have also gotten that far on a single cd('/JDBCConnectionPools/MyPool') command. WLST always remembers the cmo (Current Managed Object), the MBean corresponding to the current 'folder' we're browsing. So, these commands are equivalent from the practical point-of-view:
wls:/mydomain/config/JDBCConnectionPools/MyPool> cmo [Caching Stub]Proxy for mydomain:Name=MyPool,Type=JDBCConnectionPool wls:/mydomain/config/JDBCConnectionPools/MyPool> pwd() '/JDBCConnectionPools/MyPool'
Now, let's change a couple of random properties (see Listing 6). Remember that Python doesn't have boolean attributes. The server can return true and false (since it runs Java), but you can't assign those values. Don't worry, though; if you check it through the WebLogic console, your boolean value of 1 has been interpreted correctly by the server.
You could have gotten the same result using the equivalent techniques shown in the section above about "Automating Server Configuration." I find this way easier for systems administrators, and the first way for developers preparing scripts. It just fits better in each different kind of toolset: system administrators are more used to Unix shells, and developers feel more comfortable with the "smell" of Java.
Managing the Server Configuration Example: A Real Case
It's common to need to peep inside those nasty JDBC calls. One sometimes really wants to be able to see the conversation between the WebLogic server and the database, and why in hell the query returns 0 rows, or profile performance, okay. Logging the JDBC calls (not just the SQL, please, but the parameters too) with a hot-plug capability should be nice. Wanna give it a try?
First, let's download the p6spy JDBC driver. It is a JDBC wrapper that will log anything that goes through it. To configure it, put the p6spy.jar and the directory containing the p6spy.properties in the server classpath (don't forget the directory, or WebLogic will complain as if the JAR file were not present). Tune the p6spy.properties to your needs.
What we want to achieve is the creation of two Connection Pools, one directly with Oracle JDBC driver and the other through p6spy. Then, we will change the datasource to point to the p6spy datasource without restarting the server (if we believe the Web console interface, this change does not need a reboot).
We will start by executing the administration script developed earlier:
wls:/(offline)> execfile('AdminTool.py') Connecting to weblogic server instance running at t3://127.0.0.1:7001 as username weblogic ...
Successfully connected to Admin Server 'myserver' that belongs to domain 'mydomain'. It also is system output and should be formatted accordingly.
We can create the Connection Pool now.
wls:/mydomain/config> admin.createPool("P6SPY Connection Pool", "com.p6spy.engine.spy.P6SpyDriver") JDBCConnectionPool with name 'P6SPY Connection Pool' has been created successfully.
In the WebLogic console we can see the following (well, the WebLogic log line will only appear if you have the 'debug to console' option activated):
<28-feb-2005 20H18' GMT> <Info> <JDBC> <BEA-001132> <Initialized statement cache of size "10" for connection in pool "P6SPY Connection Pool".> 1109621928226|0|1|statement|SELECT 1 FROM DUAL|SELECT 1 FROM DUAL 1109621928242|0|1|statement|SELECT 1 FROM DUAL|SELECT 1 FROM DUAL
which shows the connection pool initializing and new connections test. We'll suppose that the dataSource doesn't exist yet. If we were clean, we would have foreseen it and created the method in our AdminTool class, but we can still do it via the interactive shell in Listing 7.
We have started directing the datasource to the P6SPY connection pool, so you can check your application and see that it really logs JDBC statements; try it with a test case. Now, there are two ways to disable the logging. Since we have the datasource in a Jython variable, we can do it the 'Java' way:
or, the 'system administrator' way shown in Listing 8.
WLST is an awesome tool capable of boosting your application server configuration and remote maintenance. It still lacks a find/locate option (for the not uncommon case where one needs to find a configuration option and can't recall its location) with wildcard support. But when it finally gets bundled with WebLogic 9 it's sure to be useful.
|[email protected] 10/03/08 09:23:49 AM EDT|
Adobe is changing the world though digital experiences. Adobe helps customers develop and deliver high-impact experiences that differentiate brands, build loyalty, and drive revenue across every screen, including smartphones, computers, tablets and TVs. Adobe content solutions are used daily by millions of companies worldwide-from publishers and broadcasters, to enterprises, marketing agencies and household-name brands. Building on its established design leadership, Adobe enables customers not o...
Oct. 1, 2016 12:30 PM EDT Reads: 605
SYS-CON Events announced today the Enterprise IoT Bootcamp, being held November 1-2, 2016, in conjunction with 19th Cloud Expo | @ThingsExpo at the Santa Clara Convention Center in Santa Clara, CA. Combined with real-world scenarios and use cases, the Enterprise IoT Bootcamp is not just based on presentations but with hands-on demos and detailed walkthroughs. We will introduce you to a variety of real world use cases prototyped using Arduino, Raspberry Pi, BeagleBone, Spark, and Intel Edison. Y...
Oct. 1, 2016 12:30 PM EDT Reads: 3,092
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
Oct. 1, 2016 12:30 PM EDT Reads: 5,525
“We're a global managed hosting provider. Our core customer set is a U.S.-based customer that is looking to go global,” explained Adam Rogers, Managing Director at ANEXIA, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Oct. 1, 2016 12:30 PM EDT Reads: 3,261
Why do your mobile transformations need to happen today? Mobile is the strategy that enterprise transformation centers on to drive customer engagement. In his general session at @ThingsExpo, Roger Woods, Director, Mobile Product & Strategy – Adobe Marketing Cloud, covered key IoT and mobile trends that are forcing mobile transformation, key components of a solid mobile strategy and explored how brands are effectively driving mobile change throughout the enterprise.
Oct. 1, 2016 12:30 PM EDT Reads: 2,325
What are the new priorities for the connected business? First: businesses need to think differently about the types of connections they will need to make – these span well beyond the traditional app to app into more modern forms of integration including SaaS integrations, mobile integrations, APIs, device integration and Big Data integration. It’s important these are unified together vs. doing them all piecemeal. Second, these types of connections need to be simple to design, adapt and configure...
Oct. 1, 2016 12:30 PM EDT Reads: 601
Ask someone to architect an Internet of Things (IoT) solution and you are guaranteed to see a reference to the cloud. This would lead you to believe that IoT requires the cloud to exist. However, there are many IoT use cases where the cloud is not feasible or desirable. In his session at @ThingsExpo, Dave McCarthy, Director of Products at Bsquare Corporation, will discuss the strategies that exist to extend intelligence directly to IoT devices and sensors, freeing them from the constraints of ...
Oct. 1, 2016 11:45 AM EDT Reads: 2,800
SYS-CON Events announced today that Sheng Liang to Keynote at SYS-CON's 19th Cloud Expo, which will take place on November 1-3, 2016 at the Santa Clara Convention Center in Santa Clara, California.
Oct. 1, 2016 11:45 AM EDT Reads: 265
Technology vendors and analysts are eager to paint a rosy picture of how wonderful IoT is and why your deployment will be great with the use of their products and services. While it is easy to showcase successful IoT solutions, identifying IoT systems that missed the mark or failed can often provide more in the way of key lessons learned. In his session at @ThingsExpo, Peter Vanderminden, Principal Industry Analyst for IoT & Digital Supply Chain to Flatiron Strategies, will focus on how IoT de...
Oct. 1, 2016 11:30 AM EDT Reads: 1,326
Complete Internet of Things (IoT) embedded device security is not just about the device but involves the entire product’s identity, data and control integrity, and services traversing the cloud. A device can no longer be looked at as an island; it is a part of a system. In fact, given the cross-domain interactions enabled by IoT it could be a part of many systems. Also, depending on where the device is deployed, for example, in the office building versus a factory floor or oil field, security ha...
Oct. 1, 2016 11:15 AM EDT Reads: 881
24Notion is full-service global creative digital marketing, technology and lifestyle agency that combines strategic ideas with customized tactical execution. With a broad understand of the art of traditional marketing, new media, communications and social influence, 24Notion uniquely understands how to connect your brand strategy with the right consumer. 24Notion ranked #12 on Corporate Social Responsibility - Book of List.
Oct. 1, 2016 10:45 AM EDT Reads: 619
Businesses are struggling to manage the information flow and interactions between all of these new devices and things jumping on their network, and the apps and IT systems they control. The data businesses gather is only helpful if they can do something with it. In his session at @ThingsExpo, Chris Witeck, Principal Technology Strategist at Citrix, will discuss how different the impact of IoT will be for large businesses, expanding how IoT will allow large organizations to make their legacy ap...
Oct. 1, 2016 10:30 AM EDT Reads: 716
Fact is, enterprises have significant legacy voice infrastructure that’s costly to replace with pure IP solutions. How can we bring this analog infrastructure into our shiny new cloud applications? There are proven methods to bind both legacy voice applications and traditional PSTN audio into cloud-based applications and services at a carrier scale. Some of the most successful implementations leverage WebRTC, WebSockets, SIP and other open source technologies. In his session at @ThingsExpo, Da...
Oct. 1, 2016 10:30 AM EDT Reads: 1,728
What does it look like when you have access to cloud infrastructure and platform under the same roof? Let’s talk about the different layers of Technology as a Service: who cares, what runs where, and how does it all fit together. In his session at 18th Cloud Expo, Phil Jackson, Lead Technology Evangelist at SoftLayer, an IBM company, spoke about the picture being painted by IBM Cloud and how the tools being crafted can help fill the gaps in your IT infrastructure.
Oct. 1, 2016 10:00 AM EDT Reads: 3,207
For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.
Oct. 1, 2016 10:00 AM EDT Reads: 3,326
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
Oct. 1, 2016 10:00 AM EDT Reads: 524
In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lea...
Oct. 1, 2016 09:45 AM EDT Reads: 843
In his session at @ThingsExpo, Kausik Sridharabalan, founder and CTO of Pulzze Systems, Inc., will focus on key challenges in building an Internet of Things solution infrastructure. He will shed light on efficient ways of defining interactions within IoT solutions, leading to cost and time reduction. He will also introduce ways to handle data and how one can develop IoT solutions that are lean, flexible and configurable, thus making IoT infrastructure agile and scalable.
Oct. 1, 2016 09:15 AM EDT Reads: 1,683
So, you bought into the current machine learning craze and went on to collect millions/billions of records from this promising new data source. Now, what do you do with them? Too often, the abundance of data quickly turns into an abundance of problems. How do you extract that "magic essence" from your data without falling into the common pitfalls? In her session at @ThingsExpo, Natalia Ponomareva, Software Engineer at Google, provided tips on how to be successful in large scale machine learning...
Oct. 1, 2016 08:30 AM EDT Reads: 2,518
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
Oct. 1, 2016 08:30 AM EDT Reads: 3,431