What is the best way to deploy Thrift Java service implementations? - java

I know Thrift has its own Threadpool server but I'm not sure it will be able to handle heavy load. Would you recommend putting it behind tomcat ?
In addition, if you wanted to use the socket transport implementation could you still use tomcat ? or would need to use some other solution ?
I would really love to hear about your experience deploying thrift java services.

Consider putting it inside application server (tomcat, jetty, etc.) and accessing it through HTTP using TServlet. You get from the server:
Threads management
Connections management
You get to use standard Filters to maybe rate limit the requests, or manage access based on cookies
Probably readily available access logs
You can easily add JSON Protocol for debugging

Related

Moving from Spring HTTP invoker to load balanced solution

Our application currently uses Spring's HttpInvokerProxyFactoryBean to expose a Java service interface, with POJO requests and responses handled by our single Tomcat server. This solution allows us to have a pure Java client and server, sharing the same Java interface. Due to increased load, we are now looking into the possibility of load balancing across multiple Tomcat instances.
It would be nice if we could make this transition while retaining the same Java interface, as this would minimise the additional development required. Googling seems to suggest that the most common solution for Tomcat load balancing is to use Apache http server together with mod_jk, but I presume this would mean using some communication mechanism other than Spring's HTTP invoker? Is there a better solution which would allow us to retain more of our current code? If not, what would be involved in transitioning between what we have now and Apache/mod_jk?
Any help would be greatly appreciated as I don't have any experience in this matter.

rmi and webservice

currently i have an web app build with Strus2 and Spring (IoC, Transactions), and i want to split this into 2 apps; one client which will contain only the web part and one core services that will be accessed via webservices and/or rmi.
I have a dilemma in what technology should i use for "glue", because i like the fact that webservices can be accessed by any clients (php,.net,...,mobile), but as i understand java rmi is faster then webservices.
I was thinking to expose the functionality via webservices and rmi in the same time... but i do not know how to do that.
Also in my current app i have a ajax action that is executed each second from the client to the server, and in this new configuration i think that there will be some performance penalties due to this.
How should i "attack" this situation ?
Thanks,
but as i understand java rmi is faster then webservices.
Why do you think this? Do you have a citation to bolster this claim?
Both RMI and webservices are using TCP/IP; both incur similar network latency. The former uses Java or CORBA serialization to send messages over the wire; the latter uses either HTTP (for REST) or XML over HTTP (for SOAP or RPC-XML).
The relative speed is far more dependent on what those services are doing and how you code them.
I would prefer a web service because simple and open win. You are restricted to RMI/CORBA clients if you use RMI.
Nice. You are running Spring and you already have all you need. Just throw in a few jars (spring webservices and related jars) and you should be good to go.
Please refer :
http://static.springsource.org/spring/docs/2.5.4/reference/ejb.html
http://static.springsource.org/spring/docs/2.5.4/reference/remoting.html

Integration of Java server application into Application Server like TomCat, GlassFish, etc

I am working on a server application that does the following:
Read data from a measuring device that is being addressed via a serial interface (javax.comm, RXTX) or sockets.
Exchange data (read and write) with another server application using sockets.
Insert data from (1) and (2) into a database using JDBC.
Offer the data from steps (1) to (3) to a JavaScript-based web app.
My current prototype is a stand-alone Java application and implements task (4) by writing the data to an XML file that is being delivered to the client via a web server (Apache), but I consider this to be a hack, not a clean solution.
This server application needs to start up and work also without any web clients being present.
I would like to integrate this server application into a Java application server, but I do not have much experience with these technologies and don't know where to start. I have tried some simple examples for TomCat and GlassFish, but that did not bring me any further because they are all built around serving web requests synchronously and stop where it would be getting interesting for me.
Is this possible to run such an app within TomCat or GlassFish?
If yes, where would be a good point to start (examples, which base classes, ...)?
Would it make any sense to split the application and implement only task (4) in a servlet, the rest in an ordinary application, communication via sockets, etc.?
Would other servers, e.g JBoss, be a better choice and if yes, why?
Edit:
The reasons I want to use a Java EE container are:
I would like to have a clean external interface for step (4).
On the long run, the application will need to scale to a huge number of simultaneous clients (at least several 10.000), so a want a standard way of scalability and application management.
In general, it's not a good idea to implement all of this in a servlet container such as Tomcat.
A servlet container is designed to service requests from a client. It sounds like you have a process which will be running all the time or at least periodically. You can do this in Tomcat, but it's probably easier to do it outside. Leave Tomcat to do what it's good at, servicing requests from browsers. It's happiest when the requests are short lived.
So I would do as you suggest, and only have step 4 in the container. You can easily interrogate the database populated in step 3, so there is no need to create web services to populate the servlet container.
For step 4, you will need to expose some services from Tomcat, either through rest, soap, whatever you like. The javascript clients can then interrogate these services. This is all completely doable with Tomcat.
For scalability, there shouldn't be a problem using Tomcat. If all it's doing is pumping data from the database to the client, there probably isn't a reason to choose a J2EE container. If you don't have need of complex transaction management or security, try using something open source. It sounds like you can get what you want from Tomcat (& hibernate & spring security if necessary). If you start to have performance problems, then the fix will probably be the same for JBoss & Tomcat: you need more servers.
My advice: stick to the simple open source solutions and move to an application server only if you find it to be necessary.
I would loosely couple the solution and not try to do everything on the Java EE/Servlet container as exchanging data using sockets (managed by the application itself) is not something you typically want to do from a Java EE/Servlet container.
Running this on a Java EE container might also be overkill as this doesn't sound like a typical enterprise application where stuff like security and transaction management is important and the app could benefit from services provided by the Java EE/Servlet container.

Can I implement a socket server on Tomcat using GenericServlet?

I would like to implement a socket server that will be connected to by multiple clients. In order to make the implementation as simple as possible and not have to code management of threads and connections etc I'd like to use Tomcat. We already use tomcat as part of our solution.
I am sure that Tomcat can be used for non http servlets and socket connections - with GenericServlet. I'd like this to be confirmed and any tips that can be given about implementations.
UPDATE - using tomcat seems the wrong tactic - little is gained from the rest of tomcat infrastructure. Anyone got other implementation suggestions? For example Apache MINA has been recommended - any others?
If you want to create support for a non-HTTP server inside tomcat you will need to implement a new protocol handler (see the docs for PoolTcpEndpoint). But at that point you're mostly going to be gaining the Catalina startup and shutdown functionality and not a whole lot else.
If you do want to base your app on a servlet container, I'd suggest jetty for size, ease of use, ability to start programatically and ability to fit completely inside the debugger.

Best Java supported server/client protocol?

I'm in the process of writing a client/server application which should work message based. I would like re-use as much as possible instead of writing another implementation and curious what others are using.
Features the library should offer:
client and server side functionality
should work message based
support multi-threading
should work behind load balancer / firewalls
I did several tests with HTTPCore, but the bottom line is that one has to implement both client and server, only the transport layer would be covered. RMI is not an option either due to the network related requirements.
Any ideas are highly appreciated.
Details
My idea is to implement a client/server wrapper which handles the client communication (including user/password validation) and writes incoming requests to a JMS queue:
#1 User --> Wrapper (Check for user/password) --> JMS --> "Server"
#2 User polls Wrapper which polls JMS
Separate processes will handle the requests and can reply via wrapper to the clients. I'd like to use JMS because:
it handles persistence quite well
load balancing - it's easy to handle peaks by adding additional servers as consumer
JMSTimeToLive comes in handy too
Unfortunately I don't see a way to use JMS on it's own, because clients should only have access to their messages and the setup of different users on JMS side doesn't sound feasible either.
Well, HTTP is probably the best supported in terms of client and server code implementing it - but it may well be completely inappropriate based on your requirements. We'll need to actually see some requirements (or at least a vague idea of what the application is like) before we can really advise you properly.
RMI works nicely for us. There are limitations, such as not being able to call back to the client unless you can connect directly to that computer (does not work if client is behind a firewall). You can also easily wrap your communication in SSL or tunnel it over HTTP which can be wrapped in SSL.
If you do end up using this remember to always set the serial version of a class that is distributed to the client. You can set it to 1L when you create it, or if the client already has the class use serialver.exe to discover the existing class's serial. Otherwise as soon as you change or add a public method or variable compatibility with existing clients will break.
static final long serialVersionUID = 1L
EDIT: Each RMI request that comes into the server gets its own thread. You don't have to handle this yourself.
EDIT: I think some details were added later in the question. You can tunnel RMI over HTTP, then you could use a load balancer with it.
I've recently started playing with Hessian and it shows a lot of promise. It natively uses HTTP which makes it simpler than RMI over HTTP and it's a binary protocol which means it's faster than all the XML-based protocols. It's very easy to get Hessian going. I recently did this by embedding Jetty in our app, configuring the Hessian Servlet and making it implement our API interface. The great thing about Hessian is it's simplicity... nothing like JMS or RMI over HTTP. There are also libraries for Hessian in other languages.
I'd say the best-supported, if not best-implemented, client/server communications package for Java is Sun's RMI (Remote Method Invocation). It's included with the standard Java class library, and gets the job done, even if it's not the fastest option out there. And, of course, it's supported by Sun. I implemented a turn-based gaming framework with it several years ago, and it was quite stable.
It is difficult to make a suggestion based on the information given but possibly the use of TemporaryQueues e.g. dynamically created PTP destinations on a per client basis might fit the problem?
Here is a reasonable overview.
Did you tried RMI or CORBA? With both of them you can distribute your logic and create Sessions
Use Spring....Then pick and choose the protocol.
We're standardizing on Adobe's AMF as we're using Adobe Flex/AIR in the client-tier and Java6/Tomcat6/BlazeDS/Spring-Framework2.5/iBATIS2.3.4/ActiveMQ-JMS5.2 in our middle-tier stack (Oracle 10g back-end).
Because we're standardizing on Flex client-side development, AMF and BlazeDS (now better coupled to Spring thanks to Adobe and SpringSource cooperating on the integration), are the most efficient and convenient means we can employ to interact with the server-side.
We also heavily build on JMS messaging in the data center - BlazeDS enables us to bridge our Flex clients as JMS topic subscribers. That is extremely powerful and effective.
Our Flex .swf and Java .class code is bundled into the same .jar file for deployment. That way the correct version of the client code will be deployed to interact with the corresponding middle-tier java code that will process client service calls (or messaging operations). That has always been a bane of client-server computing - making sure the correct versions of the respective tiers are hooked up to each other. We've effectively solved that age-old problem with our particular approach to packaging and deployment.
All of our client-server interactions work over HTTP/HTTPS ports 80 and 443. Even the server-side messaging push we do with BlazeDS bridged to our ActiveMQ JMS message broker.

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