I made a web based application by using the java language, and I would like to monitor its performance periodically (e.g. response time). Also I want to display this information on the homepage of my application. Is that possible? Can I have any idea about how this can be made.
Thanks.
You can take a look at stagemonitor. It is a open source java web application performance monitor. It captures response time metrics, JVM metrics, request details (including a call stack captured by the request profiler) and more. The overhead is very low.
Optionally, you can use the great timeseries database graphite with it to store a long history of datapoints that you can look at with fancy dashboards.
Example:
Take a look at the github page to see screenshots, feature descriptions and documentation.
Note: I am the developer of stagemonitor
Depending on your environment, I would use a cron job or task that measures the response time to request your app using something like HttpClient. Then drop that information into a database table accessible by your app.
The answer here is the simplest way you can measure the time: How do I time a method's execution in Java?
Why not checkout Munin monitoring? The website says
Munin the monitoring tool surveys all your computers and remembers
what it saw. It presents all the information in graphs through a web
interface. Its emphasis is on plug and play capabilities. After
completing a installation a high number of monitoring plugins will be
playing with no more effort.
SLAC at the Stanford university also keeps a large, quite well sorted list with various solutions for network monitoring among other things. SLACs list of Network Monitoring Tools, check for instance "Public domain or free network monitoring tools".
You can also consider to create your own custom web application monitor. Therfore, use the ProxyPattern and and create a concreate monitor. By using Spring framework you can easily swich on and off the monitor during runtime without re- deployment or restart of the web application. Furthermore you can create a lot of different specific monitors by yourself and are able to control what is beeing monitored. This gives you a maximum of flexibility, but requires a bit of work.
It is possible.
The clearest way to go about it, providing true numbers is to simulate a client that performs some sort of activity that mimics the real usage. Then have that client periodically use the website.
This presupposes that your website has a means to accept inputs that do not impact the real back end business. Crafting such interfaces requires some thought, but is not beyond the ability of a person who could put together the web site in the first place. The key points are to attempt to emulate as much using the real website as possible, but guard against real business impact. Basically it is designing for a special user (the tester).
So you might have a special user that when logged in, all purchases are bound to a special account that actually is filtered out to appropriately not demand payment and not ship goods. Provided the systems you integrate with all share an understanding of this live testing account, you can simultaneously test alongside of real production post-deployment.
Such a structure provides a huge benefit. You get performance of the real, live running system. Performance tends to change over time, and is subject to the environment. By fetching your performance numbers on the live system, in the same environment, you get a much better view of what real users might be encountering. Also, you can differentiate and track performance for different activities.
Yes, it is a lot more to design and set up; however, if you are in it for the long run, the benefits are huge.
I guess JavaMelody is the most appropriate solution for you. It can be built into a Java application and due to this feature, it monitors the functionality inside the app. Using this platform, it’s possible to get much more specific parameters for your Java app, than via external monitoring. In addition, it allows you displaying some statistics on your app homepage. Moreover, you can build in the app the graphs from JavaMelody, that essentially facilitates the app monitoring.
Take a look at the detailed overview of JavaMelody: http://cases.azoft.com/enterprise-system-monitoring-solutions-business-apps/
Related
I'm trying to make simple application and deploy it on Google Cloud Platform Flexible App Engine, which will contain two main parts:
Front end application (simple Web UI based on Java 8 (Spring + Thymeleaf) with OAuth authorization from different external sites)
Back end application (monitoring several resources in separate threads, based on logged in users and reacting to their input in a certain way (behavioral changes))
Initially I was planning to make them as one app, but I think that potentially heavy background processing may cause failures in my front end application part + App Engine docs says that deployed services behave similar to microservice architecture.
My questions are:
Do I really need to separate front end from back end, if I need to react to user input as fast as possible? (but delays up to 2 seconds aren't that critical)
If I do need to separate them (and I strongly believe that I do) - how to I set up interaction between applications?
Each resource must be tracked exactly by one thread on back end - what are the best practices about this? I thought about having a SQL table with a list of acquired resources, but the flaw I see there is if an instance will fail I will need to make some kind of clean up on that table and redetermine which resources are actually acquired.
Your proposed architecture sounds like the right approach in separating the two into different services for the following reasons:
Can deploy code for each separately, rollback versions separately, and split traffic separately for experiments or phased rollouts.
Can adjust machine types and memory allocations for each service to better suit its needs. If you're doing work that is memory intensive on the backend, you can adjust that service's settings to allocate more memory per instance.
Allow each type of service to scale independently based on demands, which should result in better utilization of the services and less waste. This should also lower your overall spending than if you tried to go for a one-sized fits all approach in a single monolithic service.
You can mix different runtime environments across services. For example, you can mix language runtimes within a project OR you could even mix between standard and flexible environments. Say your front-end code is more cost efficient in standard, designate that service as a standard environment service and your backend as a flexible environment service. Or say you need a customer docker file with Perl in it, you could do that as a flexible environment custom runtime and have your front-end in Java 8.
You can still share common services like Cloud SQL, PubSub, Cloud Tasks (currently in alpha) or Redis for in memory caching. Your works don't need t reside in App Engine, they could reside in a different product if that better suits your needs.
Overall, you get much better control over your application to split it apart. The biggest benefit likely comes down to optimizing your application for spending only on what you need.
I think that you are likely to be able to deploy everything as an appengine app except if you use some exotic Java libraries that are not whitelisted. It could still be good to deploy it with compute engine for increased configurability and versatility.
You can create one front-end instance and one back-end instance in compute engine and divide the resources between them like that. Google's documentation has an example where you can do that.
First of all, I have a conceptual question, Does the word "distributed" only mean that the application is run on multiple machines? or there are other ways where an application can be considered distributed (for example if there are many independent modules interacting togehter but on the same machine, is this distributed?).
Second, I want to build a system which executes four types of tasks, there will be multiple customers and each one will have many tasks of each type to be run periodically. For example: customer1 will have task_type1 today , task_type2 after two days and so on, there might be customer2 who has task_type1 to be executed at the same time like customer1's task_type1. i.e. there is a need for concurrency. Configuration for executing the tasks will be stored in DB and the outcomes of these tasks are going to be stored in DB as well. the customers will use the system from a web browser (html pages) to interact with system (basically, configure tasks and see the outcomes).
I thought about using a rest webservice (using JAX-RS) where the html pages would communicate with and on the backend use threads for concurrent execution.
Questions:
This sounds simple, But am I going in the right direction? or i should be using other technologies or concepts like Java Beans for example?
2.If my approach is fine, do i need to use a scripting language like JSP or i can submit html forms directly to the rest urls and get the result (using JSON for example)?
If I want to make the application distributed, is it possible with my idea? If not what would i need to use?
Sorry for having many questions , but I am really confused about this.
I just want to add one point to the already posted answers. Please take my remarks with a grain of salt, since all the web applications I have ever built have run on one server only (aside from applications deployed to Heroku, which may "distribute" your application for you).
If you feel that you may need to distribute your application for scalability, the first thing you should think about is not web services and multithreading and message queues and Enterprise JavaBeans and...
The first thing to think about is your application domain itself and what the application will be doing. Where will the CPU-intensive parts be? What dependencies are there between those parts? Do the parts of the system naturally break down into parallel processes? If not, can you redesign the system to make it so? IMPORTANT: what data needs to be shared between threads/processes (whether they are running on the same or different machines)?
The ideal situation is where each parallel thread/process/server can get its own chunk of data and work on it without any need for sharing. Even better is if certain parts of the system can be made stateless -- stateless code is infinitely parallelizable (easily and naturally). The more frequent and fine-grained data sharing between parallel processes is, the less scalable the application will be. In extreme cases, you may not even get any performance increase from distributing the application. (You can see this with multithreaded code -- if your threads constantly contend for the same lock(s), your program may even be slower with multiple threads+CPUs than with one thread+CPU.)
The conceptual breakdown of the work to be done is more important than what tools or techniques you actually use to distribute the application. If your conceptual breakdown is good, it will be much easier to distribute the application later if you start with just one server.
The term "distributed application" means that parts of the application system will execute on different computational nodes (which may be different CPU/cores on different machines or among multiple CPU/cores on the same machine).
There are many different technological solutions to the question of how the system could be constructed. Since you were asking about Java technologies, you could, for example, build the web application using Google's Web Toolkit, which will give you a rich browser based client user experience. For the server deployed parts of your system, you could start out using simple servlets running in a servlet container such as Tomcat. Your servlets will be called from the browser using HTTP based remote procedure calls.
Later if you run into scalability problems you can start to migrate parts of the business logic to EJB3 components that themselves can ultimately deployed on many computational nodes within the context of an application server, like Glassfish, for example. I don think you don't need to tackle this problem until you run it to it. It is hard to say whether you will without know more about the nature of the tasks the customer will be performing.
To answer your first question - you could get the form to submit directly to the rest urls. Obviously it depends exactly on your requirements.
As #AlexD mentioned in the comments above, you don't always need to distribute an application, however if you wish to do so, you should probably consider looking at JMS, which is a messaging API, which can allow you to run almost any number of worker application machines, readying messages from the message queue and processing them.
If you wanted to produce a dynamically distributed application, to run on say, multiple low-resourced VMs (such as Amazon EC2 Micro instances) or physical hardware, that can be added and removed at will to cope with demand, then you might wish to consider integrating it with Project Shoal, which is a Java framework that allows for clustering of application nodes, and having them appear/disappear at any time. Project Shoal uses JXTA and JGroups as the underlying communication protocol.
Another route could be to distribute your application using EJBs running on an application server.
We have a need to monitor performance of our java web app. We are looking for some tolls which can help us with this task. The major difficulty is that we are SaaS provider with multi-tenant server architecture with hundreds of customers running on the same hardware. So far we tried commercial products like DynaTrace and Coradinat but unfortunately they don't get the job done so far. What we need is a simple report which would tell us if we had performance problems on each customer site in a specified period of time. Mostly it will be response time per customer but also we will need some more specifics based on the URLs.
please let me know if someone had any experience with setting up such monitoring.
Thanks!
Take a look at stagemonitor. It is an open source java web application performance monitoring library capable of multi-tenancy. It captures response time metrics, JVM metrics, request details and more. The overhead is very low. It uses the great timeseries database graphite that automatically downsamples historical datapoints which leads to a low storage overhead.
Here is a screenshot. You can find more on the project site.
Note: I am the developer of stagemonitor
HypericHQ is nice for this because, being written in Java itself, it integrates quite nicely with all the MBean properties already exposed on your APP server. You can set up administrator alerts/charts based on JVM properties/app server MBean properties that most non-Java tools can't get at.
On the downside, it does like to run a relatively heavy (as these things go) agent on your server.
-I am not in any way affiliated with Hyperic Inc ;)
I always seem to have this internal struggle when it comes to user interface. I build up an application "engine" and tend to defer user interface to after I get my algorithms working. Then I go back and forth trying to decide how to let a user interact with my program. Personally, I'm a fan of the command line, but I can't expect that of my users generally.
I really like what's possible in the browser in the age of web 2.0 and ajax. On the other hand it's not so hard to make a Swing front-end either, and you can generally count on a more consistent presentation to the user (though using a good javascript framework like YUI or jQuery goes a long way toward normalizing browsers).
Clearly both approaches have their merits and drawbacks. So, what criteria / parameters / situations should lead me to use a lightweight (e.g. web-based) GUI? What criteria / parameters / situations should lead me to use a heavier (e.g. Swing-based) GUI?
It is not my intent to start a flame war, merely interested in the community's constructive/objective opinions.
Edit #1
In light of the first few responses, I would like to clarify that I would like to deploy my application regardless, not host it on some internet server necessarily. So I would have to deploy with a light-weight web-server infrastructure a la Jetty/Tomcat or similar.
It depends on the application and this is essentially a usability driven question (though there are considerations like data storage and platform requirements). Think of the pros and cons.
Pros of a lightweight Web UI:
Ease of distribution
Platform independent
Ease of maintenance
Cons of a lightweight Web UI:
Less environmental control
Markup standards vary between browsers
Requires a web server and everything that goes with it
Pros of an executable UI
More environmental control (i.e.: full screen applications, etc)
Not necessarily subject to latency and outages
Cons of an executable UI
Pushing updates may be more difficult
Requires installation
Potential platform requirements (frameworks, packages, etc)
Potentially requires knowledge of advanced networking topics (web services, etc)
One small factor you may want to consider is that the user will have go through some type of installation (albeit minimal) if you distribute a swing application.
Also a web application will allow you to accurately track the usage of your application (via google analytics or something similar). Not sure if that's a concern but it may be useful to you in the future.
If it is a client-server application I would normally go for a web frontend for the application.
You will save yourself of countless problems with things like installed JRE versions, distributing upgrades, application permissions, disappeared shortcuts...
You need to break the requirements of the application down to decide this...
Do the users have Java of sufficient version installed? It will need to be, to run a Swing GUI.
Do you have a web server?
Do you need the flexibility of a Swing GUI or the accessibility of the web interface?
Is Java Webstart and option, if so, you can distribute a Swing GUI via the web.
Does your application perform extensive calculations or processing? If so, a client app may be the answer.
There are a million questions such as these. I would suggest a brain storming session and keeping track of all the pros and cons of each, adding a point score, than throwing it all away and going with your gut feeling :)
If you anticipate there being frequent updates to the app then web based may be better since the user would not have to update the client or install a new client containing the updates.
If you think that the user may need the ability to use the app while not conencted to the internet then swing would be better.
Just two things off the top of my head.
Think about the users and use cases of your project.
Do users expect to have access to it when they're disconnected from the Internet (for example, on an airplane or in a coffee shop with no Internet access)? Use Swing.
Do you want users to be able to access the same tool from different computers (for example, both at work and at home)? Use a web UI.
Also consider whether the user needs to save and load data, and whether the tool produces data files that some might consider sensitive (if so, storage on the web might be an issue).
Do make a quick guess I often try to ask myself/customers if the application has a high "write" demand.
For a mostly read-only application a thin-client solution is perfectly well suited.
But if a lot write actions are needed then a swing desktop application has more flexibility.
Personally I always prever a swing desktop application. It can easily deployed using Java Webstart.
Not knowing anything about your application I can not give the best recommendation possible. However I can state from personal/professional experience that installing an application on clients machines is a LOT more of a pain in the ass than it seems.
With AJAX/web you really only have to worry about supporting like three browsers. Installation messes/updates are only felt once when you deploy the product to the web server.
With like a stand-along Swing app, you get to deal with the really really big mess that is installing the application onto unknown systems. This mess was so bad that things like AJAX were really pushed along to make web apps behave/feel like a real native app.
I have an application that's a mix of Java and C++ on Solaris. The Java aspects of the code run the web UI and establish state on the devices that we're talking to, and the C++ code does the real-time crunching of data coming back from the devices. Shared memory is used to pass device state and context information from the Java code through to the C++ code. The Java code uses a PostgreSQL database to persist its state.
We're running into some pretty severe performance bottlenecks, and right now the only way we can scale is to increase memory and CPU counts. We're stuck on the one physical box due to the shared memory design.
The really big hit here is being taken by the C++ code. The web interface is fairly lightly used to configure the devices; where we're really struggling is to handle the data volumes that the devices deliver once configured.
Every piece of data we get back from the device has an identifier in it which points back to the device context, and we need to look that up. Right now there's a series of shared memory objects that are maintained by the Java/UI code and referred to by the C++ code, and that's the bottleneck. Because of that architecture we cannot move the C++ data handling off to another machine. We need to be able to scale out so that various subsets of devices can be handled by different machines, but then we lose the ability to do that context lookup, and that's the problem I'm trying to resolve: how to offload the real-time data processing to other boxes while still being able to refer to the device context.
I should note we have no control over the protocol used by the devices themselves, and there is no possible chance that situation will change.
We know we need to move away from this to be able to scale out by adding more machines to the cluster, and I'm in the early stages of working out exactly how we'll do this.
Right now I'm looking at Terracotta as a way of scaling out the Java code, but I haven't got as far as working out how to scale out the C++ to match.
As well as scaling for performance we need to consider high availability as well. The application needs to be available pretty much the whole time -- not absolutely 100%, which isn't cost effective, but we need to do a reasonable job of surviving a machine outage.
If you had to undertake the task I've been given, what would you do?
EDIT: Based on the data provided by #john channing, i'm looking at both GigaSpaces and Gemstone. Oracle Coherence and IBM ObjectGrid appear to be java-only.
The first thing I would do is construct a model of the system to map the data flow and try to understand precisely where the bottleneck lies. If you can model your system as a pipeline, then you should be able to use the theory of constraints (most of the literature is about optimising business processes but it applies equally to software) to continuously improve performance and eliminate the bottleneck.
Next I would collect some hard empirical data that accurately characterises the performance of your system. It is something of a cliché that you cannot manage what you cannot measure, but I have seen many people attempt to optimise a software system based on hunches and fail miserably.
Then I would use the Pareto Principle (80/20 rule) to choose the small number of things that will produce the biggest gains and focus only on those.
To scale a Java application horizontally, I have used Oracle Coherence extensively. Although some dismiss it as a very expensive distributed hashtable, the functionality is much richer than that and you can, for example, directly access data in the cache from C++ code .
Other alternatives for horizontally scaling your Java code would be Giga Spaces, IBM Object Grid or Gemstone Gemfire.
If your C++ code is stateless and is used purely for number crunching, you could look at distributing the process using ICE Grid which has bindings for all of the languages you are using.
You need to scale sideways and out. Maybe something like a message queue could be the backend between the frontend and the crunching.
Andrew, (in addition to modeling as a pipeline etc), measuring things is important. Have you ran a profiler over the code and got metrics of where most of the time is spent?
For the database code, how often does it change ? Are you looking at caching at the moment ? I assume you have looked at indexes etc over the data to speed up the Db ?
What levels of traffic do you have on the front end ? Are you caching web pages ? (It isn't too hard to say use a JMS type api to communicate between components. You can then put Web Page component on one machine (or more), and then put the integration code (c++) on another, and for many JMS products there are usually native C++ api's ie. ActiveMQ comes to mind), but it really helps to know how much of the time is in Web (JSP ?) , C++, Database ops.
Is the database storing business data, or is it being also used to pass data between Java and C++ ? You say you are using shared mem not JNI ? What level of multi-threading currently exists in the APP? Would you describe the code as being synchronous in nature or async?
Is there a physical relationship between the Solaris code and the devices that must be maintained (ie. do all the devices register with the c++ code, or can that be specified). ie. if you were to put a web load balancer on the frontend, and just put 2 machines up today is the relationhip of which devices are managed by a box initialized up front or in advance?
What are the HA requirements ? ie. just state info ? Can the HA be done just in the web tier by clustering Session data ?
Is the DB running on another machine ?
How big is the DB ? Have you optimized your queries ie. tried using explicit inner/outer joins sometimes helps versus nested sub queries (sometmes). (again look at the sql stats).