IBM Impact 2011 was a wildly busy week! Customer meetings, entertaining keynotes, informative sessions, and hands-on labs packed the 6 days with more than enough action. I spent a lot of the week presenting sessions and conducting labs for the newly announced IBM Workload Deployer. As one would expect with any new announcement, we got tons of questions about IBM Workload Deployer. While I cannot capture all the questions and their answers here, I will try to cover some of the more prevalent ones below.
Question: What happened to WebSphere CloudBurst?
Answer: The short answer is, it simply went through a rename. WebSphere CloudBurst became IBM Workload Deployer v3.0. The version 3.0 acknowledges this is an evolution of what we started with WebSphere CloudBurst, which was at version 2.0. Why remove WebSphere from the name? The fact that this is now an IBM branded offering is more accurate as it is capable of deploying and managing more than just WebSphere software.
Question: What is new in IBM Workload Deployer?
Answer: While there are many new features that I will be talking about over the coming months, the most prominent new facet is the introduction of workload patterns (also referred to as virtual application patterns). As opposed to topology patterns (traditionally referred to as simply patterns in the WebSphere CloudBurst product), workload patterns raise the level of abstraction to the application level. Instead of focusing on application infrastructure and its configuration as you do with topology patterns, workload patterns allow you to focus on the application and its requirements. When using workload patterns, you provide the application, attach policies that specify functional and non-functional requirements, and deploy. IBM Workload Deployer handles deploying and integration the middleware infrastructure necessary to support the application, and it automatically deploys your application on top of that middleware. In addition, IBM Workload Deployer manages the application runtime in accordance with the policies that you specify in order to provide capabilities such as runtime elasticity.
Question: If I am a current WebSphere CloudBurst user, what does this mean for me?
Answer: Not to worry. You will be able to use all of your WebSphere CloudBurst assets (patterns, scripts, images) in the new IBM Workload Deployer. All of the capabilities previously in WebSphere CloudBurst are present in IBM Workload Deployer (terminology may vary slightly -- topology pattern instead of just pattern for instance). Additionally, we continue to expand on the functionality that you are familiar with from WebSphere CloudBurst. This includes updates for Environment Profiles, new IBM Hypervisor Edition images, new pattern building capabilities, and more. Stay tuned for more information about these new features and for information on how you can move your WebSphere CloudBurst resources to the new IBM Workload Deployer.
Question: How do I choose between using workload and topology patterns?
Answer: There are a number of factors that will lead you to using either workload patterns, topology patterns, or both. The primary decision point will be how much control you really need (not want). When using workload patterns, you sacrifice some customization control over the configuration, integration, and administration of the middleware application environment since the workload pattern and management model abstracts away the 'guts' of the system. Everything about the workload pattern is application-centric. On the other hand, topology patterns give you intimate control over the configuration, integration, and administration of the middleware application environment. As a general rule of thumb, if your application requirements match the capabilities of a workload pattern, that is the way to go as it can greatly reduce complexity and cost associated with deployment and management. If a workload pattern does not meet the needs of your application, topology patterns can still greatly reduce cost and complexity and you can tailor them to fit almost any need. Beyond generalities, there is no hard and fast rule for choosing one over the other. It comes down to understanding your application environment and its needs.
Question: Is IBM Workload Deployer an appliance like WebSphere CloudBurst?
Answer: Yes, it is still an appliance, but an updated one! The new appliance is 2U, and it provides more storage, processing power, and memory. It is still just as easy to setup, but just slightly bigger.
Well, that is all for now, but I will be back many times over the coming months with more information. In the meantime, if you have any questions, please leave them in a comment below.
If you read some of my entries from time to time, chances are you know that you can use WebSphere CloudBurst to apply interim fixes and fixpacks to your deployed virtual systems. When you choose to apply either a fix or fixpack, WebSphere CloudBurst temporarily stops the virtual system, takes a snapshot of the system (the entire WebSphere cell), applies the fix or upgrade, and then starts the system back up. The result is an updated, running WebSphere cell, and if you need to, you can rollback the virtual system to the previous configuration by simply clicking a button.
In WebSphere CloudBurst 1.0 the application of fixes and upgrades were applied via the web console which made it hard to automate this process. However, in WebSphere CloudBurst 1.1 you can use the command line interface to apply fixes and fixpacks to virtual systems. The appliance still takes the actions I described above, thus the process is still simple, safe, and fast. The only difference is the interface through which you drive the application of the maintenance.
What does it look like? Quite frankly, it's very simple. You can go through all of my virtual systems and apply both fixes and fixpacks with the seven line script below:
for virtualSystem in cloudburst.virtualSystems:
fixes = virtualSystem.findFixes()
if len(fixes) > 0:
upgrades = virtualSystem.findUpgrades()
if len(upgrades) > 0:
You can write this script once, save it as a Jython file, and run it with the CLI's batch mode anytime you want to roll out maintenance to your virtual systems. It's really amazing to me that the above SEVEN lines are capable of rolling out all fixes and all upgrades within your WebSphere CloudBurst catalog to every virtual system the appliance is managing. I can't think of an easier or safer way to automate the deployment of fixes/upgrades to your WebSphere environments.
Let me know if you have any questions. As always you can reach me on Twitter @WebSphereClouds.
One of the things that often comes up at some point in IBM Workload Deployer conversations is the notion of self-service access. Specifically, users want to know what the appliance provides that enables them to allow various teams in their organization to directly deploy the middleware environments they need. In other words, they want to use IBM Workload Deployer to tear down the traditional barriers that exist between those that request the environment and those that fulfill said request. Now, as we begin to elaborate on this notion, it becomes quickly apparent that in order to effectively enable self-service, IBM Workload Deployer must deliver a few things.
First, IBM Workload Deployer must provide the means to define users with various levels of access. Second, IBM Workload Deployer must provide the means to define resource access at a fine-grained level to different users and groups of users. Check and check. The appliance has been doing this since the beginning of WebSphere CloudBurst. Without those two things, the conversation of self-service access would end pretty quickly. However, there is a final capability that is equally important: IBM Workload Deployer must deliver a means to limit resource consumption at a fine-grained level.
In IBM Workload Deployer there are a couple of ways to achieve this. First, you could define multiple cloud groups and allow access to those groups in a way that maps directly to resource entitlements. While that may work in some situations, others call for even more granularity. You may want to allow multiple different users or groups to access a cloud group, but you may want to allow different consumption limits for each of these groups. In this situation, you can take advantage of environment profiles and a new option when defining users of IBM Workload Deployer.
Consider the case that you have a group of developers and you want to limit their consumption of memory in the cloud. First, you start by defining your development users and for each you select Environment Profile Only as the value for the Deployment Options field.
By selecting the above value for the deployment options of a user, you restrict that user to only deploying via an environment profile as opposed to general cloud group deployments. After defining all of your development users, you may choose to organize them into a user group for easier management. At that point, you can define environment profiles and determine which ones your developers should have access to using the Access granted to field of the profile.
Within the environment profile, you can define resource consumption limits for compute resource and software licenses. For instance, you can define a limit on the amount of virtual memory consumed by all deployments using the profile. It is important to note that the limit is cumulative for ALL deployments that use the profile.
Now that all of the controls are in place, consider the deployment process for one of your development users. They pick a virtual system pattern, click the deploy icon and begin to configure the pattern for deployment. In the Choose Environment section of the deployment dialog, your development user will only be able to select the Choose profile option for deployment. Further, they will only be able to deploy using the environment profiles to which they have access.
After the deployment completes, a look at the Environment limits section in the profile shows the current usage totals.
Now suppose another development user, or even the same one, comes along and attempts to deploy another virtual system pattern even though the profile limits have already been reached. The user can initiate the deployment, but they will get a near immediate failure owing to the fact that they would exceed consumption limits if the deployment were allowed to proceed.
The same kind of enforcement occurs regardless of the resource limit type. You can use this approach to limit the consumption of CPU, virtual memory, storage, or software licenses among the various different users or groups of users you define in IBM Workload Deployer. If you combine fine-grained resource consumption limits with varying permissions and fine-grained access, I think you are on the road to truly enabling self-service in the enterprise.
Script packages are an integral part of virtual system patterns in IBM Workload Deployer. By attaching script packages to your patterns, you provide customizations particular to your unique cloud-based middleware environments. Customizations provided by script packages might include installing applications, creating application resources, integrating with external enterprise systems, and much more. The bottom line is, if you are creating virtual system patterns, you will almost certainly be creating script packages.
Largely, the act of creating a script package is independent of IBM Workload Deployer. The appliance does not dictate a particular scripting language, so all you need to do is make sure you can invoke your logic in the operating system environment. Your script package may be a wsadmin script, shell script, Java program, Perl script, and on and on. After you create the actual contents of your script package, you will then load that asset into the IBM Workload Deployer catalog.
Once loaded into the catalog, you define several attributes of your script package, including the executable command, command arguments, variables, execution time, and more. The process for defining these attributes is trivial using the intuitive UI in IBM Workload Deployer, but I wanted to take a little time to remind you of a technique I recommend to all users defining script packages. You can actually package a JSON file within the script package that defines all of the script's attributes. The format of the file is simple, and I am including an example below:
The example above is one taken from a script package in our samples gallery, and it shows the basics of which you need to be aware. Notice that in the JSON file, you can provide a name, description, unzip location, executable command, command arguments, variables, and more. You only need to ensure that the name of this JSON file is cbscript.json and that you include it at the root of the script package archive. Once you have done that, you load the script package archive into the catalog, refresh the script package details, and voila -- all the attribute definitions appear!
You may ask why I recommend this since it could seem like an unnecessary step. My answer to that is that you have to define these attributes anyway, so you might as well capture it once in the file. Once you capture it once in the file, you can ensure that if the same script needs to be reloaded, or if you need to move it to another appliance, its definition will be exactly the same (and presumably correct). I use this approach for all of my work, and for all of the samples I contribute to our gallery, and it really saves me a lot of misplaced effort that can result from typos. If you are out there creating script packages, try adopting this approach. I'm pretty sure you will be happy you did!
Since the IMPACT conference, there has been quite a bit of buzz around the new features, capabilities, and enhancements coming in WebSphere CloudBurst 2.0. In addition to the updates for the appliance, there are some updates to the IBM Hypervisor Edition virtual images as well. In particular, there is one new offering that I want to make sure is getting more than a mere 15 minutes of fame.
What is this new offering that deserves some time in the spotlight? Well, it is the Intelligent Management Pack for the WebSphere Application Server Hypervisor Edition. Still not sure what this is? Simply put, it is an optional add-on to the WebSphere Application Server Hypervisor Edition that enables WebSphere Virtual Enterprise capabilities in the environments dispensed by WebSphere CloudBurst.
If you are not familiar with WebSphere Virtual Enterprise, this still may not mean much yet. Essentially, the use of the Intelligent Management Pack means you create environments that contain capabilities to dynamically manage your application runtime environment. This includes, but is not limited to, the following capabilities:
Dynamic clustering: Create WebSphere Application Server clusters whose membership changes autonomically in order to meet the needs of your applications. You create service level agreements to define the needs for your applications.
Application health monitoring: Monitor the health of your applications by assigning health policies. These policies designate the condition to monitor for (i.e. memory leaks), and they dictate what action to take in case the condition occurs (i.e. restart the server).
Application editioning: Manage multiple versions of your applications and roll out new versions of your applications without incurring downtime. This is essential if you consistently deliver updates to your applications deployed in production environments.
On-Demand routing: Build WebSphere CloudBurst patterns that include On-Demand Router parts. On-Demand Routers are a key component of WebSphere Virtual Enterprise environments and act as an enabler of some of the functionality discussed above.
If you are a user of WebSphere Virtual Enterprise, or otherwise knowledgeable with the product, the Intelligent Management Pack should be pretty familiar to you. When you deploy a pattern built from WebSphere Application Server Hypervisor Edition with the Intelligent Management Pack, you end up with a WebSphere Virtual Enterprise cell. When you log into the administration console, you will see the WebSphere Virtual Enterprise console. You can use any of the features in the normal WebSphere Virtual Enterprise product in the environment created by WebSphere CloudBurst.
Be on the lookout for more information concerning the Intelligent Management Pack. I know there is an article in the works, and we will also be working on some short demos for our YouTube channel. In the meantime, please reach out to me here or on Twitter (@damrhein) with any questions or comments.
Can you have cloud computing without virtualization? I don't think so. Some have stated to me that they believe a cloud could b contrived without virtualization but I don't see it. Cloud computing is all about being able to expand or contract an enterprise on demand and as a service. Without deployable virtual images there is no mechanism for doing this efficiently.
I suppose that you could argue that clouds do not necessarily include the OS or the hardware and that you could scale by use of templates and configuration files to clone systems. That is cloning. Cloning, spawning, parallel processing and other mechanisms for creating capacity and processing power dont have the scope that a full cloud implementation has. Cloud computing is an administration paradigm that may share or even employ some or all of these other techniques but can include more.
I guess the biggest thing that sets cloud computing apart from cloining or spawning is that cloud computing is a paradigm for a flexible distributed computing platform. Cloning and spawing are techniques as is Virtualization.Clouds are entire managed infrastructures where virtulized systems are simply tools and cloning is a function of products.
It's here at long last! IBM PureSystems was announced today and in particular the IBM PureApplication System family member. IBM PureApplication System includes many of the capabilities that you have been hearing about and using in IBM Workload Deployer. While this solution includes and builds upon the capabilities of Workload Deployer, there's also a lot more functionality that is built into a completely integrated and optimized solution that not only manages your private cloud but runs it in the most optimized fashion. It really is a complete private cloud solution that is highly optimized to provide the best possible integration of software and hardware made simple for your cloud needs.
Looking for a reminder of the difference a year can make? If so, just take a look at the last year or so for the WebSphere CloudBurst product. Since about this time last year, we have seen the release of versions 1.1, 1.1.1, 2.0, and 126.96.36.199, each one bringing their own set of major enhancements and features. Owing to this aggressive pace, it is sometimes easy to miss out on the latest capabilities of the product. For that reason, I wanted to give a brief rundown of some (definitely not all) of the major additions to WebSphere CloudBurst over the past year.
PowerVM and z/VM support: WebSphere CloudBurst 1.1 introduced support for PowerVM (based on Power5 and Power6 systems), and version 1.1.1 introduced support for z/VM. This means that a single WebSphere CloudBurst Appliance can provision to VMware, PowerVM, and z/VM virtualization platforms.
Power7 support: WebSphere CloudBurst 188.8.131.52 introduced support for Power7 systems, thus allowing users to take advantage of the significant enhancements provided by Power7 via WebSphere CloudBurst deployments.
Expansion of the IBM Hypervisor Edition portfolio: The portfolio of images that you can deploy using WebSphere CloudBurst now includes WebSphere Application Server, WebSphere Process Server, WebSphere Portal Server, WebSphere Business Monitor, WebSphere Message Broker, and DB2. In addition to adding new images, we also expanded the platform and operating system support for existing images. For example, you can take advantage of the Red Hat Enterprise Linux OS for WebSphere Application Server Hypervisor Edition, and you can deploy WebSphere Process Server Hypervisor Edition to z/VM infrastructure.
Addition of the Intelligent Management Pack: The Intelligent Management Pack is an optional feature of the WebSphere Application Server Hypervisor Edition that allows you to take advantage of autonomic, policy-driven runtime management capabilities in your deployed environments. This includes the ability to create proactive health policies for your environments, assign SLAs to your applications, manage the update of applications, and more.
License management capabilities: In WebSphere CloudBurst version 2.0 and later, you can make use of license monitoring and management functionality. This allows you to get both point-in-time and historical views of software PVU usage within your cloud, and it allows you to setup policies concerning the usage of PVUs for WebSphere CloudBurst deployments.
Environment profiles: WebSphere CloudBurst provides quite a bit of out-of-the-box deployment automation in terms of selecting hypervisors, assigning IP addresses, and more. However, sometimes you need more control over exactly how this happens. WebSphere CloudBurst 184.108.40.206 introduced environment profiles that you can use to exercise more control over how deployment happens in WebSphere CloudBurst.
In my view, this is quite an impressive list of features delivered within a year's time. I should also reiterate that this is by no means a complete list, but just a selection of some of the major enhancements during this time. If you have any questions about the above additions, or if you have any questions on other features, please let me know.
Customers are always impressed when they learn about the simplicity, resiliency, and rapid time to value they can received from virtual applications. However, they are usually a little mystified at how virtual applications really work. After all - they have become quite accustomed to doing things the "traditional way" where they control every aspect of their applications manually. Virtual Applications represent an entirely new way of thinking. Sure, the benefits are enormous but can you really trust them? How is it doing all of this anyway?
What seems like "magic" is really a sophisticated and coordinated set of activities driven and coordinated by IBM Workload Deployer while leveraging the expertise built into the pattern type. Yes, you can trust it because experts have worked to build the system and created to it react and respond much faster than you can. When moving away from manual processes to automated processes it is always nice to get a sense of what is really happening. I think it is just human nature. We can't really place our trust in something until we have first hand experience or understand what it is really doing ... I guess it is the critic inside each one of us. Even after you've experienced the value it is still reassuring to see and understand the "how".
It is the "how does it do that?" type of question that I attempted to answer for virtual applications in a blog post I wrote on the Expert Integrated Systems blog recently. It attempts to pull the curtain aside and describe what is actually happening to support a virtual application pattern. As with my previous post - this was written for IBM PureApplication Systems but the concepts are 100% applicable to IBM Workload Deployer. I think you will find it interesting ... Continue reading ...
Dustin and i manned the IBM booth at InterOp in Las Vegas last week. The conference was very different from the industry conferences I remember, but then again I haven't been to one in a long time. I don't recall seeing boxing matches, light shows or bikini models but I think they are a welcome addition.
Ostensibly this conference was focused on cloud computing and was even called the "Cloud Summit". However, in the vendor area, there were few real cloud computing specific peds. Most of the vendor displays were about hardware, system monitoring and security.
Ric Telford of IBM gave a keynote address and sspoke of IBM's cloud offerings. After the keynote, there was a flurry of visitors asking about IBM, Cloud Computing and IBM's cloud offerings. Most of the visitors were looking for education and we were happy to have the opportunity to talk about the company and cloud computing from IBM's perspective.
We had the CloudBurst Appliance with us and it drew some interest. The purple case definitely stood out and drew inquiries. Some excitement is being generated but I think now the industry and the market has to catch up to us.
I write a lot about WebSphere CloudBurst script packages. Typically, I write about what they are, how to create them, and even provide some samples from time to time. I find that most of the time I'm either writing or talking about script packages from the standpoint that they allow you to automate the delivery of customizations to environments you deploy with WebSphere CloudBurst. More specifically, I usually explain how you can include these script packages in your patterns to ensure that your custom scripts execute as part of every pattern deployment. The truth is, that is not the whole story. In fact, it's only 1/3 of the story.
In WebSphere CloudBurst, when you define a script package you also define its execution mode. The execution mode can be one of three values, and it indicates the invocation time for the script. The default value is at virtual system creation, and that tells WebSphere CloudBurst to automatically invoke the script as part of the deployment process. This seems to be the most commonly used execution mode, and in the original version of WebSphere CloudBurst it was the only available mode (which probably attributes to why I only usually tell 1/3 of the story here). As you may expect, there is a wide range of usage scenarios for this class of script packages including installing applications, activating monitoring agents, registering cells with an externally managed DNS server, and much more.
If you are like me (and many humans), you enjoy and actually expect symmetry. In that regard, it probably comes as no surprise that there is a script package execution mode called at virtual system deletion. As the name indicates, this class of script packages executes as an automatic part of the virtual system deletion process. When a user tells WebSphere CloudBurst to remove a virtual system, before it shuts down the machines in the system, it will run each script package marked to execute at virtual system deletion. Typical use cases for these scripts include removing information about the cell from externally managed DNS servers, freeing up connections with external systems, and other external 'clean up' activities.
So this leaves the final execution mode for script packages, the when I initiate it mode to be precise. This class of script packages executes when explicitly triggered by a user. In the virtual machine detail section for a deployed virtual system, you can see a list of user-initiated script packages for a given machine. There is a start button by each of the user-initiated script packages that allows you to invoke the script when, and as many times as you need to. While these script packages have many different use cases, the most common use case is to deploy application updates. Users build these application update scripts, attach them to a pattern, and invoke them whenever they want to deliver an updated application into their already deployed environment.
WebSphere CloudBurst script packages are one of the main vehicles for delivering your customizations to your cloud environments. The three execution modes mentioned above allow you to determine when the right time to deliver those customizations is.
May is almost here and that means that IBM IMPACT is right around the corner. Just like years past, IMPACT 2010 will be a great chance to get valuable education and insight into IBM WebSphere software and software from across the IBM software family. If you want to hear how IBM software is leading the march toward a smarter planet, register now.
IMPACT 2010 will be a great chance to hear the WebSphere cloud computing story. There will be multiple sessions on the WebSphere CloudBurst Appliance. These include customer-led sessions, internal adoption stories, overviews, and much more. I'll be there running a hands-on lab and delivering a session that discusses integration between WebSphere CloudBurst and IBM Rational tools. Of course, there is more to WebSphere and cloud computing than WebSphere CloudBurst. We have several other sessions that will detail all of IBM WebSphere's work in the cloud.
If you are interested, I put together a short video discussing some of the sessions on tap for WebSphere and cloud computing at IMPACT 2010. I'd also encourage you to check out the social media site for IBM IMPACT 2010. On that site, you will find tweets, videos, and blogs about the conference. Don't forget to sign up, and I hope to see you in Las Vegas!
-- Dustin Amrhein
We've begun to seed this location with all sorts of helpful information on IBM Workload Deployer. Check it out and you will find links to a "getting started" section, articles, demos, redbooks, whitepapers, pointers to various blogs where authors write about private clouds or IBM Workload Deployer (yep, this blog is included), links to product documentation and education assistant, upcoming events, and more included in the wiki. We're still populating this location with content and we're looking for input on how to improve things ... so please provide your feedback and check back often to see how it evolves.
The content provided in the community is open and visible to everyone immediately. However, there is even more value if you create an id (or use your existing developerWorks id) to become a member of the community. Members can participate in the many collaborative elements that the community provides. This includes the ability to open discussions and collaborate on the forum, post blog entries in the IBM Workload Deployer community blog, or even share content that you have created which may be of interest to others.
There is even a specific section in the community focused on the Plugin Developer's Kit that Dustin mentioned in the previous post on extensibility ( see IBM Workload Deployer PDK wiki page ).
So please visit this new IBM Workload Deployer community and send us your feedback so that we can improve and grow this into a valuable resource. Ultimately, we want this to be a place where we can help each other be successful using IBM Workload Deployer. We also want to learn valuable insights from your experiences with IBM Workload Deployer so that we can continue to make improvements and optimizations in the appliance with the goal of improving your private cloud experience, making your business more agile and efficient. As always, please send us your feedback.
Among the major features of the new virtual application pattern in IBM Workload Deployer is the notion of elasticity. That is, as your application needs more resources, it gets them. When your application can meet its SLAs with fewer resources, the environment shrinks. With this kind of pattern, you enable elasticity by specifying a policy and defining the scaling trigger (i.e. CPU usage, application response times, database response times, etc.). What may have been a bit lost in some of these new announcements regarding IBM Workload Deployer is the fact that you can now leverage this core feature of cloud, elasticity, in your virtual system patterns.
If you have read this blog in the past, you probably already know that the Intelligent Management Pack is an option for virtual system patterns built using WebSphere Application Server Hypervisor Edition. When you enable the Intelligent Management Pack option, you are essentially building and deploying WebSphere Virtual Enterprise (WVE) environments. For those of you not familiar with WVE, the best way to describe it is that it provides you with application and application infrastructure virtualization capabilities. Of its many capabilities, one most germane to our discussion today is the ability for users to attach SLAs to applications and then have WVE automatically prioritize requests and manage resources in order to meet those SLAs. Inherent in this capability is the ability to dynamically start and stop application server processes (JVMs) as required. In other words, WVE provides JVM elasticity.
The fact that WVE provides JVM elasticity is nothing new. Further, IBM Workload Deployer started providing virtual machine (VM) elasticity in previous versions (when it was WebSphere CloudBurst). With this feature, you could add or remove VMs to an already deployed virtual system using dynamic virtual machine operations provided by the appliance. The catch was that the VM elasticity was a manual action and you could not link this elasticity to the same SLAs tied to your applications. Well, thanks to a new feature in WebSphere Virtual Enterprise and easy integration provided by the Intelligent Management Pack, this is no longer the case.
Starting in IBM Workload Deployer 3.0, you can take advantage of a new WVE feature called Elasticity Mode when using the Intelligent Management Pack. Elasticity mode is not unique to IBM Workload Deployer, but a concept new to the base WVE product. It allows one to define actions for how WVE should grow and shrink the set of nodes used by application server resources. Like the basic JVM elasticity capability in WVE, these node elasticity actions trigger based on SLAs tied to your applications. Consider the case that you are using elasticity mode and your application is not currently meetings its SLA. If WVE does not think it can start any more application server instances on the current set of nodes, it will grow the set of nodes per your elasticity configuration. Conversely, if WVE detects that it can meet SLAs with fewer nodes, it will shrink the resources per your elasticity configuration.
In IBM Workload Deployer, using elasticity mode becomes even easier. All you need to do is use the Intelligent Management Pack and enable the elasticity mode option in your virtual system patterns. When you do this, you get automatic integration between IBM Workload Deployer and the deployed WVE environment. What does that mean? It means that if WVE detects it needs more nodes, it will automatically call back into IBM Workload Deployer and request that the appliance provision a new VM that will serve as a node for application server processes. It also means that if WVE detects it could meet SLAs with fewer resources, it will call into IBM Workload Deployer and ask it to remove a node. All of this happens without any user scripting. All you have to do is enable this option in your patterns and configure SLAs appropriate for your applications.
To me, this exciting new feature brings out the best of elasticity capabilities in both IBM Workload Deployer and WebSphere Virtual Enterprise. The result is a single management plane that gives you both VM and JVM elasticity for your cloud-based application environments. Best of all, elasticity actions map directly to SLAs for your applications. After all, when it comes to cloud, it's the application that really matters!
The reason I suggest the application proxy approach is twofold. First, it affords you the ability of having custom interactions with the REST API. For instance, you may insert logic into the server-side proxy code that returns only a subset of the JSON data contained in the response from the appliance. Alternatively, in an effort to reduce the chattiness on your client-side, you may join JSON data from multiple different REST requests to the appliance to fulfill a single client request. You may even decide to represent the data in an all together different format than JSON. All of these options and many more are available to you if you implement an application-based proxy to the REST API.
The second reason I suggest the application approach is that it is easier, and seemingly safer, to not deal with user passwords on the client-side. If you setup your application proxy, you can configure it to retrieve the appropriate password from a secure location (like an encoded file) based on information passed along in the request. This means the password information is only present in the request (in encoded form of course) from the application proxy to the WebSphere CloudBurst Appliance.
The good news about the application-based proxy approach is that it is simple to put in place. I composed one using the open source Apache Wink project. The Apache Wink project is an open source implementation of the JAX-RS specification (and then some), and it enables you to develop POJOs that are in turn exposed in a RESTful manner. In my case, I had a single resource POJO:
The Apache Wink runtime routes any HTTP GET request whose path is like /resources/* to the getResources method in the WCAResource class. This method passes along information taken from the query string (the host name of the target WebSphere CloudBurst Appliance and the requesting WebSphere CloudBurst username), as well as the HTTP path information and sends it on to the getResource method declared as follows:
The getResource method above uses the WebSphere CloudBurst host name and the request path to construct the URL for the corresponding WebSphere CloudBurst REST API call. Next, it constructs an Apache Wink Resource object and sends the REST request along to the WebSphere CloudBurst Appliance. How do we authenticate this request? We use the WebSphere CloudBurst username (sent as a query string parameter) to retrieve the appropriate encoded password information. Once we have that, we construct the necessary header for basic authorization over SSL.
The application-based proxy shown here is simply a pass-through. It does not manipulate the data returned from the WebSphere CloudBurst REST API, nor does it map a single client-side call to multiple REST requests. However, it would be simple enough to extend it to do any of those things. If you have any questions about the code here, please let me know. I'd be happy to share more of the code, or talk about how and where to extend it.