grails run-app will start my app in an embedded tomcat server.
I would like to configure this embedded server so that only a single request processor thread is available and that multiple threads are processed serially rather than concurrently (similar to default webrick behaviour in the rails world)
Is it possible? If so, how do I do it?
As far as I know, this is not directly supported by the Tomcat plugin. But you could easily modify the Tomcat plug-in and run your own version.
If you look at the class org.grails.tomcat.TomcatServer, you will see it starts a Tomcat instance.
Here is the doc for this class: http://tomcat.apache.org/tomcat-7.0-doc/api/org/apache/catalina/startup/Tomcat.html
There is a getConnector() method which will return the default HTTP connector. Once you have it, you can probably change the settings, like maxThreads.
But be careful the performance will be awful. But I guess you already know that.
Related
Is it possible to run a Spring Boot REST API service on top of Node.js instead of Tomcat,
or if not Node.js which are the other possible servers on which we can run our Spring Boot REST Application.
Please help me figure it out.
NodeJs is a server to run Javascript code. It can not run a Java web application, which needs a JVM (Java Virtual Machine) to be run into a JVM. Before you ask, no, NodeJS can not run a JVM. Is is just not made for that. To understand what I mean, it's like wanting a car to run with a outboard engine... Definitly not possible.
So NO, you can't run your Spring Boot REST Application on the top of NodeJs server.
If you don't want to use a Tomcat, then there is other options for you:
https://blog.idrsolutions.com/2015/04/top-10-open-source-java-and-javaee-application-servers/
I'm wondering how the Common Unix Printing System "CUPS" handels the user actions and affects the configuration files, from my humble background, a webpage only can access/edit files when there is some web server and a serverside script, so how it works without installing web server?
does it work through some shell script? if yes, how that occurs?
It is not the web frontend that alters the configuration files. At least not if you compare it to the 'typical' setup: http server, scripting engine, script.
CUPS itself contains a daemon, this also acts as a minimal web server. That deamon has control over the configuration files. And it is free to accept commands from some web client it serves. So no magic here.
Turned that around you could also setup a system running a 'normal' http server with such rights that is is able to alter all system configuration files. That's all a question of how that server/daemon is setup and started. It breaks down to simple rights management. You certainly do not want to do that, though ;-)
I need to make an application that runs as a server that accepts connections from various clients and responds to their requests (via proprietary protocol). This server also needs a GUI for configuration and monitoring. I (of course) need to run the server as a service, and the GUI has to be available only at certain moments. Since the server service and GUI share some of the hardware resources and part of the configuration they would run on the same machine. I would like that the GUI and the whole long running service are one process that will run in the background; the GUI would than be invoked (shown) only when needed.
My question is: can this be done with a JavaFX 2 GUI and how?
Thanks in advance
Josip
So you need Monitoring and Management in a Java application? You should be using the Java Management Extensions (JMX) Technology. http://docs.oracle.com/javase/6/docs/technotes/guides/management/overview.html
And if you decide that you can't just use a standard JMX client or create a plugin then you create your JavaFX application as a JMX client.
I'm looking at an existing website, deployed on an NFS server. I'd like to rewrite some portions of it to run on nodejs. As far as I can tell, nodejs isn't supported by the NFS folk, but I am constrained to using their servers.
So, is there a way to shoe-horn nodejs onto a nearlyfreespeech server? Has anyone tried this successfully?
As of 24/September/2014 NFS now support persistent processes:
Intro and overview - More power, more control, more insight, less cost
Official example - How-To: Django on NearlyFreeSpeech.NET
3rd party example - Run node.js on NearlyFreeSpeech.Net
To summarise the process described in mopsled.com's third-party example:
1) In NFS.N's admin UI, select your site's domain shortname under Sites, then change that site's "Server Type" to "Custom" instead of PHP / Apache.
2) Put your Node server code somewhere in /home/protected/
3) Create a shell script (eg run.sh) file somewhere in /home/protected/ that contains the command(s) to start your server (eg npm run start or node server.js). NFS.N will automatically run this script as a continuous process using a "Daemon", which we'll configure in the next step.
4) Select "Daemons" in your site's NFS.N admin UI, and enter your server's startup shell script path in the "command line" field. Complete the other fields as you see fit.
5) NFS.N will now ensure that your custom server process will run indefinitely. Your web server will now be available at the port your server listens at. However, NFS.N doesn't give root access for your server to communicate through the normal "low-level" internet ports (eg :80 and :443), so if you want to serve those, you must use NFS.N's "Proxy" feature described in the next step.
6) If you need to listen on low-level ports: select "Add a Proxy" in your site's NFS.N admin UI and enter the relevant settings, checking the "Bypass Apache entirely" option and giving the port your server is listening on for the "Target Port" option.
That's it! You can now stop/restart the server's continuous process (the shell script that the Daemon is maintaining) in the Daemon's configuration page.
NFS.net have a new "NFGI" architecture that may open the possibility to this:
NFGI can be made to work with other languages as well, making them first-class citizens of our service, just as fast and integrated as PHP currently is. This paves the way for making all sorts of frameworks viable that have traditionally been too slow when run through CGI. Rails. Catalyst. Django. We also believe it can be leveraged to make node.js work on our service, but we’re not 100% sure about that.
(Source: http://blog.nearlyfreespeech.net/2013/09/21/cgissh-upgrades/)
If you want this feature you can vote for it in their feature request system at https://members.nearlyfreespeech.net/support/voting
Although to be honest, I concur with earlier answers, using Node via CGI would lose some of the benefit...but would not be without its charms. Something like http://larsjung.de/node-cgi/ for NFS.net would be an interesting JavaScript replacement for PHP.
The problem is not that NFS.net will not support NodeJS. The thing is that you can't have "long running processes", i.e. servers. Since you can't run servers, you can't run Node.
In fact, the only way you can have anything dynamic there is by using CGI. There's no reason why Javascript engine could not be used to generate pages in response to requests, but I am not sure that can be done with node.
I am trying to set up a development environment for node.js. I assumed at first that it requires something similar to the traditional, "localhost" server approach. But I found myself at a loss. I managed to start a node.js hello world app from the terminal. Which doesn't looked like a big deal - having to start an app from the console isn't that hard. But, after some tweaking, I found out that the changes aren't shown in the browser immediately - you need to "node [appName here]" it again to run.
So, my question is:
Is there a software or a tutorial on how to create a more "traditional" development server on your local machine? Along with port listening setup, various configurations, root directories etc (things that are regular in stacks like XAMMP, BitNami or even the prepackaged Ubuntu LAMP). Since I'm new at node.js, I can't really be sure I'm even searching for the right things on google.
Thanks.
Take a look at :
https://github.com/remy/nodemon
it'll allow you to do - nodemon app.js
and the server will restart automatically in case of failure.
To do this I built a relatively small tool in NodeJS that allows me to start/stop/restart a NodeJS child process (which contains the actual server) and see/change configuration option and builds/versions of the application, with admin options available on a different tcp port. It also monitors said child process to automatically respawn it if there was a error (and after x failed attempts stops trying and contacts me).
While I'm prohibited from sharing source code, this requires the (built-in) child_process module, which has a spawn method that returns a child process I guess, which contains a pid (process id) which you can use with the kill method to kill said child process. Instead of killing it you could also work with SIGINT an catch it within your child application to first clean up some stuff and then exit. It's relatively easy to do.
Some nice reading material regarding this.
http://nodejs.org/docs/v0.5.5/api/child_processes.html