I'm using spring boot and uses the fat jar for production, which is pretty cool.
However, the way I'm deploying forces the application to be shutdown for about 15 seconds when redeploying, because I have to kill the running jar and start the new one. I haven't found any solutions for this, i.e. how to reload the new jar without a restart.
Is it possible to "hot reload/replace" the jar or would I have to run in a container, like tomcat, and deploying a war?
Please note that it's in production so I guess dev-tools is out of question.
It's more infrastructure question I guess.
You can create second "reserve"instance running your app.
When you are updating your app on the main instance - all users requests must be redirected to the second "reserve" instance. When the redeploy is finished - you redirect the request to the main instance again. And then redeploy app on the reserve instance. For example Nginx may help you with those redirections.
Related
do not judge this question) I want to implement WEB installer for my Spring Boot application, and very interesting moment is that my application plays 2 role: Installer and Backend(Application). When i first run my app i need to tell Spring to not initialize particular beans(Hibernate(while startup application must not to be failed to start because database may not exist), ActiveMq and others beans that will be added in installation process) and show some html pages with installation guide. Also i need to prevent access to endpoints where some logic with database occurs. When installation finished i will create new application.properties or some other file with settings and i tell Spring to initialize all required beans with Hibernate, ActiveMQ and others. Maybe i will make restart of application and new behaviour that based on installation will occur. And in next starts my application will not show installation guide. To simplify the question: I need to change startup behaviour of Spring Boot Application. For fun i can give an example with human: I need to make human live with no organs, and this human will live very good, and if i want i can add organs to human and he will be live very well))
You can use #Profile annotation. Check this link: https://www.mkyong.com/spring/spring-profiles-example/
I'm maintaining an old Spring project and it's startup time is very long. The app is running under Tomcat 7 and using Hibernate 4.3 + PostgreSQL 9.5. This is the log from IntelliJ IDEA that is being written on app start (uploaded to Pastebin due to SO post length limitations). Notice that time gap between 3rd and 2nd lines from the bottom. It seems that nothing is happening during that time. I've tried to set all log levels to TRACE but still haven't seen any other output to log. The question is how can I reduce the startup time? This is the things I've already tried:
set default-lazy-init=true on the main context configuration file;
set hibernate.hbm2ddl.auto to none on the persistance config;
set hibernate.temp.use_jdbc_metadata_defaults to false on the persistance config.
Non of them produced any measurable results. What else can I try? At least how can I understand what is happening during all this time?
I would suggest you to copy the .war file of your application to the webapps folder and let tomcat do the deployment, it is quicker and will save your time.
Tomcat supports hot deployment. Tomcat monitors the deployment directory for changes, so you can just copy the .war file into that directory, and the server will undeploy/redeploy.
You can write a script using ANT to automate the deployment process.
I want to extend the users admin portlet that is located in the control panel. I hooked the jsp and wanted to use methods from the service builder that are in the same hook as the jsp.
The problem is that the jsp can not find the classes. So I copied the *-service.jar to the tomcat lib/ext folder and removed it from the hook when deploying it.
But that doesn't work. After a while I get an exception that says Cache is not alive or this web application instance has been stopped already.
Is there a way to use methods from my custom service builder in the hooked jsp ?
The approach you have taken is correct, i.e. to put the *-service.jar inside [TOMCAT_HOME]/lib/ext and removing the jar from the hook.
The error might be because the hook may not have been properly undeployed, you may get some idea from this forum post. So my suggestion would be to:
Undeploy the hook
Stop the server
Copy the jar to [TOMCAT_HOME]/lib/ext
Clear temp and work directory
Restart the server
Deploy the hook
Whenever you remove a jar from a plugin-project and then just deploy without undeploying the portlet, sometimes you may notice that the jar file may be still present in the deployed webapps/plugin-project's directory, and this might be the case here as well. Also, whenever you put something in the global classpath (i.e. [TOMCAT_HOME]/lib/ext) you need to restart the server.
Also, don't forget to import the class in the JSP :-), just in case ...
I have a requirement that I need to use a single server machine to run 2 totally different applications.
The server machine has Apache Tomcat 6.0 installed. 1 of the applications is deployed on it and is running successfully for a long time. Initially, the clients used to connect to it by invoking the url "http://machine-name/1stProjectName/initialPage". I have also mentioned the "initialPage" as the Welcome Page in web.xml of this project. But somehow, later some ports or relating things were changed by the server maintenance team, and to connect to the application, now one has to use the url "http://machine-name" or "http://machine-name/initialPage", i.e. the machine name has started behaving like the project name folder because now if I invoke the url "http://machine-name/1stProjectName/initialPage", it gives 404 error saying that "/1stProjectName/1stProjectName/initialPage" resource not available.
Now, when I deploy the WAR of the second application into the webapps folder of Tomcat (just like I did for the first application), it unpacks it properly. But, the issue is how do I connect to this second project. If I use "http://machine-name", it takes me to the 1st application and if I use "http://machine-name/2ndProjectName/initialPage", it gives me an error that "/1stProjectName/2ndProjectName/initialPage" not available.
Kindly help or guide me in some direction.
Thanks in advance.
Your URLs should look like this if you did things properly:
Project 1: http://host:port/war-name-1
Project 2: http://host:port/war-name-2
That means no changes to content.xml to modify the path.
I would talk to your "server maintenance team" and let them know what you are trying to do (since they are the ones who made these changes in the first place). But it sounds to me that they just mapped a path to a specific location, that is your machine-name root is mapped to 1stProjectName.
I'm working on a project in Java using the spring framework, hibernate and tomcat.
Background:
I have a form page which takes data, validates, processes it and ultimately persists the data using hibernate. In processing the data I do some special command (model)
manipulation prior to persisting using hibernate.
Problem:
For some reason my onSubmit method is being called twice, the first time through things
are processed properly. However the second time through they are not; and the incorrect
information is being persisted.
I've also noticed that on other pages which are simply pulling information from the data
base and displaying on screen; Double requests are happening there too.
Is there something misconfigured, am I not using spring properly..any help on this would
be great!
Additional Information:
The app is still being developed. In testing the app I'm running into this problem. I'm using the app as I would expect it to be used (single clicks,valid data,etc...)
If you are testing in IE, make note that in some versions of IE it sometimes submits two requests. What browsers are you testing the app in?
There is the javascript issue, if an on click handler is associated with submit button and calls submit() and does not return false to cancel the event bubble.
Could be as simple as users clicking on a link twice, re-submitting a form while the server is still processing the first request, or hitting refresh on a POST-ed page.
Are you doing anything on the server side to account for duplicate requests such as these from your users?
This is a very common problem faced by someone who is starting off. And not very sure about the application eco-system.
To deploy a spring app, we build the war file.
Then we put it inside 'webapps' folder of tomcat.
Then we run the tomcat instance using terminal (I am presuming a linux system).
Now, we set up env in that terminal.
The problem arises when we set up our environment for the spring application where there can be more than one war files to be deployed.
Then we must cater to the fact that the env must be exclusive to a specific war file.
To achieve this, what we can do is create exclusive env files for every war. (e.g. war_1.sh,war_2.sh,.....,war_n.sh) and so on.
Now we can source that particular env file for which we have to deploy its corresponding war. This way we can segregate the multiple wars (applications) and their environment.