I've uploaded my Rails app from a svn repository to my server. In my localhost it works ok, but when I try to access by Chrome I get the following error:
There appears to be a database problem.
Your config/database.yml may not be written correctly. Please check it and fix any errors.
Your database schema may be out of date or nonexistant. Please run rake db:migrate to ensure that the database schema is up-to-date.
The database server may not be running. Please check whether it's running, and start it if it isn't.
I've no idea what to do, because it's the first time I try to upload a rails project and I'm doing the same things I do in localhost in remote server.
By the way, should I run rails s too throught the ssh connection?
Update: first thing to do is get educated on deploying: start here on the Rails site.
So the thing is, on your server you need to have a database set up, like you do on your local machine. Checking out the code from SVN only gets you the application, not the database.
You mention in the title that you have Passenger set up on the server. Passenger is a module of Apache (or Nginx) which replace the rails s command you are using in development. It is in this passenger configuration file that you'll need to set the RailsEnv <something> to determine what and how the app starts and runs.
If the database servers are the same (e.g. MySQL on both platforms) and the environments are the same (e.g. "development"), and if the app/db/database.yml file is checked into source control, then skip ahead.
If your database and environment is different (e.g. SQLLite in development and MySQL in production) then you'll need to add the necessary configuration -- database name, host, port, usename, password for the environment in the database.yml (and specify the proper database gem in your Gemfile, based on the environment). If you are storing passwords, I don't recommend checking in the database.yml file, but that's a separate topic. In the end, you need to have the right database config in database.yml on the server.
Then, you can run bundle exec rake db:setup on the server from your app's root directory. This will initialize the database with the current schema, and run any seeds.rb setup needed. Check with rake -T to see other options you might consider.
Once that's done, subsequent deployments require that you check out your latest code from SVN, and usually restart the app (with Passenger, this is done with the command touch tmp/restart.txt from the app's root directory. If you have made changes to the database structure, before restarting, run bundle exec rake db:migrate
Oh, yeah, in production, if you're using the default environment, you'll also need to run bundle exec rake assets:precompile the first time, and every time afterwards if you have added images, changed javascript/coffeescript or css/sass files.
Having said this, #rwilliams comment about Capistrano is definitely something you'll want to think about. Deploying is tricky as you can see, and as your app gets bigger you'll want it to be simple. Capistrano allows you to set up a script of things that make deployment a command like cap deploy or cap staging deploy:migrations. It's a lot to learn, but worth the effort.
Related
I have a web server which is presenting some data from a Cloudera cluster. The data are stored on HBase and the cluster is secured with Kerberos. When I try to perform a get, the server hangs without logging any error.
So far I've tried:
Launching the webserver from command line after a kinit (the server is just for testing purpose, so log-in duration and complex procedures to start it are not an issue)
The runAs approach described in here, both with and without the configuration file import from this answer.
The CLASSPATH configuration approach described here
Global authentication with UserGroupInformation.loginUserFromKeytab (with and without all the configurations from point 2 and 3)
I've executed all the gets from hbase shell after kiniting with the web server's user and they work in reasonable time (less than a second, while the last time I left the connection open the server didn't respond in over an hour), so it's not a performance or authorization issue. Inside the same web server, with every configuration listed, I'm able to perform other actions, like connecting to HBase and getting the table instances.
I've also checked the logs from Kerberos, HBase and my web server and none of them presents any error. In fact, I'm pretty much afraid that the authorization works, but it just gets stuck in some loop during the get.
UPDATES: After more testing, I've verified that there is a user set right before the call to HBase's API. Also, I've checked and no calls are made to HBase. So this is not an authentication problem, but something else. Did anybody have the same problem?
I want to develop a Java based Webservice on my laptop. This webservice will take one input parameter, query my SQL Server database and will fetch information and will return it back.
I know, I do not need a webservice here. But, right now, I am just testing my android application which will call this webservice and will show return data on my device.
So, I have developed a java program which connects my SQL Server Database (which is present on my laptop) and returns a value against the parameter passed. I have made it a webservice by creating endpoints and publishing it from another class.
For reference, something like answer on this thread
So, when I run it from my Eclipse, I can go to a browser and run my webservice, pass parameter and get result.
But, once I close my eclipse, its no more accessible. I am new to this and after studying I am guessing that I will need IIS to host it on my laptop.
I want to ask, whether it is possible to run/publish it locally on my laptop as a background process so that I can test my android app by calling the same?
Future scope -
I am going to deploy this webservice in my company which will connect my database. Both webservice and sql server will be on same machine. I am going to call this webservice remotely over internet from my android device to show the results.
I guess, I will need IIS in future right? Is there any other way to fulfill this requirement? Please provide some ideas.
If, within Eclipse, you can get your web application deployed so that it is accessible via a browser, then you definately can do it without eclipse.
Eclipse uses plugins like Tomcat or Glassfish to run your webserver. These programs are available outside of Eclipse as standalone services. You can install these and run them as background processes at the command line.
Just figure out which one you are using in eclipse (or which one you want to use) and look for a standalone copy on the web.
Here's Tomcat, btw.
I am done with this.
What I did is, I went to Eclipse, selected my Project-> Right Click -> Export -> Under General -> Ant Buildfiles
This created, Build.xml in my Project directory.
I deleted all the class files and recompiled them using ant command.
In my case, target name was build-project which compiles all the java files.
So, I did ant build-project
Note - This was done as Eclipse was using different JDK version.
Now, I called my publish class to publish my webservice with
ant publish
This was half done as this was running in interactive mode.
Then I created a bat file with following command -
"path_for_ant_bin_directory\ant" -buildfile "path_to_build_file\build.xml" publish
This was opening up the command box. So, I created a vb script to run the bat file in background
Set oShell = CreateObject ("Wscript.Shell")
Dim strArgs
strArgs = "cmd /c path_to_bat_file\my_bat.bat"
oShell.Run strArgs, 0, false
And, now it nicely runs in background and I can access my webservice.
Hope it helps someone with similar requirement.
I was wondering if it was possible to get an SQLITE manager database onto a server? What i mean by this is so that when i complete my program in a java project and make an installer for that project. Anyone who downloads it from any computer running on any operating system who has administration rights can access the database without having connection issues. In addition anyone who logs in to the program can do so with full database connection.
Is there a way to do this? I also don't want the user who is going to install the program to install any additional programs for the database. In addition i would like this program to work on any computer who might not have the SQLITEManager plugin on there firefox web browser or even have firefox installed on there computer.
I would also like the admin to be able to edit anything on the online server the database should be on.
If this is not possible on SQLITE Manager could you recommend a database which can do this but also use and work on the code already made for the sqlite programs?
SQLite databases are just flat-files. What this means in layman's terms:
I download your database as a file.
I can modify it as I please.
I'm not forced to synchronize to the newer version of the flat-file.
You have a choice: You either write your code to force periodic synchronization of the SQLite flat-file to your clients, or you use a dedicated DBMS on your server, such as MySQL, and force your clients to connect to that.
We have a web application hosted on this webLogic server on a UNIX machine. Its primarily a JSP/Servlet based app. Whenever we do a modification/enhancemment to any one of those JSps or servlets, I precompile them on my local and deploy them on the UNIX system. For example, if there is a file called GetIdServlet.class, we usually rename the existing file to say GetIdServlet.class1 and then put in the new file as GetIdServlet.class. This is just to be able to revert back to the original file in case they are needed. However, I notice very strange behaviour. The application loses some functionality whenever we stop and start the server. The functionality may be back on the next or a few restarts after that. For example, a submit button that is supposed to direct it to the next page just stops working. It may start working after a few restart.
However on my local(Eclipse + webLogic) there is absolutely no issue. Everything works fine. Any ideas on what's going wrong?
You are using Unix Environment and i assume that the local desk setup used is windows OS or MAC. thus, when you copy the class files you are using some tool like WinSCP.
in case so, then please set the copy settings of such tool to use binary method of copying the files.
Example in WinSCP. go to Options->Preferences->Select Transfer in the Side Menu->under the Transfer Mode section, Select Binary option as the Transfer Mode. This will ensure that the binary replica is created on the Unix environment and that no data is lost in the transfer.
I want to place a server program written in Java on the cloud. It would accept TCP socket connections from clients (clients are android phones using 3G), do some computations, save stuff to a MySQL database (also on EC2), and send stuff back to the clients over the TCP connections. It may even be necessary to create several instances of the server (i.e. a process group).
Is this easy to do? I think I can make a AMI, but I'm not sure how to upload Java files, compile and run them, and create a MySQL database etc
Any help would be much appreciated.
Take a look at using Amazon Elastic Beanstalk. Beanstalk is Amazon's PaaS offering and it will alleviate a lot of the system administration burden. Here's a quick description from their docs:
AWS Elastic Beanstalk is an even
easier way for you to quickly deploy
and manage applications in the AWS
cloud. You simply upload your
application, and Elastic Beanstalk
automatically handles the deployment
details of capacity provisioning, load
balancing, auto-scaling, and
application health monitoring.
Also, if you're interested in using MySQL then you should look at Amazon RDS. Again, this will alleviate the system administration burden for your database tier. Here's a quick description from their docs:
Amazon Relational Database Service
(Amazon RDS) is a web service that
makes it easy to set up, operate, and
scale a relational database in the
cloud. It provides cost-efficient and
resizable capacity while managing
time-consuming database administration
tasks, freeing you up to focus on your
applications and business.
Is this easy to do? I think I can make
a AMI, ...
I think the answer depends on how comfortable you are with system administration in general. Creating a AMI to run in EC2 is really pretty much the same as creating a physical server or a VM image. You'll need to install an operating system, and then install tools, libraries and programs you need (like mysql, the jdk, ssh, etc).
You can save yourself a little work by using one of Amazon's pre-built AMI's http://aws.amazon.com/amis/. But, ultimately, you'll be responsible for all system administration of the server. If you've never built a server from the ground up, you have a pretty big learning curve ahead of you. It's not insurmountable, but just be warned that the devil is in the details; there's a ton of stuff you'll need to learn ;-)
... but I'm not sure how to upload Java
files, compile and run them, ...
Once the server is setup and running in EC2, compiling them and running java files is just the same as compiling and running on your local. Normally, you probably want to compile and package your java app into a jar or war and then transfer that up to your EC2 server. If you install linux os on your EC2 server, you can use scp or a FTP client to transfer your files over sftp to move the files from your local up to the server. Once the latest files are up on your server, you can ssh to the server and start your app.
... and create a MySQL database etc ...
Installing mysql is going to be specific to the OS you choose to install on your server. For example, you can install mysql easily on Ubuntu with a command like:
sudo aptitude install mysql
Again, there will be more system-admin-type stuff to learn here specific to mysql databases.
So, it's definitely doable. An experienced sys admin could build a AMI instance pretty easily/quickly. If this is your first experience with system administration, I'd suggest finding an old Desktop you have lying around and try installing Ubuntu and all the required libraries and tools you need (mysql, jdk, ssh, etc..). Get your java program working on the old desktop and then it should be pretty easy to create an AMI from that. Then you can run your custom AMI on EC2 and will be set up.
If you don't have a spare desktop lying around, you can use one of the Virtual Machine products like VMWare Player or Sun's VirtualBox and build a server instance on one of those.
If you want to avoid the hassle of managing the entire install of the Operating system, you might want to look at services like slicehost and/or linode instead of EC2. They give you ssh access to a pre-installed server. And it's as easy as clicking a button to install programs like mysql, etc.
Hope this answer is relevant and helpful, good luck.
- Dave
If you can use Tomcat as your server - you might want to try Amazon Web Services Elastic Beanstalk It will greatly simplify your task by providing an easy instance of Tomcat to deploy.
EDIT: AWS has a full section on how to develop using Java here: http://aws.amazon.com/java/
How comfortable are you with remote administering a server and solving problems most people have never heard of? That's what you're talking about.
You'll create your EC2 instance, log into it and configure it like you would any other server you're working with. You can download JDKs to it, dbs etc. You might consider using a tool like Chef to help you. You'll use ftp and scp to copy files to the server.
You're probably going to want your Java server on one box and have it talk to a separate db server since you say you may want multiple servers.
Once the server is working the way you like it you can create an image of it to use to launch multiple instances, then configure a load balancer to point at your servers.
If you can create a MySql db on your local box you can create it in the cloud. If not?....
Running Applications needs app. s/w to run them.
Apps such as Cyber Duck helps to upload files via SFTP.
I am successful in doing the same problem addressed.. Trust me, YOU CAN DO IT. All u need is interfaces for server services such as MySQL (use WorkBench to connect using key pair), terminal access (using PUTTY/SSH via MAC) and well you are good to go
I think to get started is to use a a whole unit packed into one archive.
Think of it as you have your Java files compiled, a embedded http server say tomcat. Now all of this packed in a jar ready to be deployed on Amazon's EC2. Use this link for more on embedded servers and relevant code.
As far as database is concerned, you can use Amazon's RDS. You can configure mysql on RDS and obtain a link to it for connection. Amazon RDS would help you to get started with database.
Now that you have everything ready to start and work with application. Now is the time to deploy on Amazon AMI
Perform Following steps to deploy you app on Amazon EC2:
Create a server instance on Amazon EC2 refer EC2 getting started.
Receive Private key file i.e. .pem(receive from Step 1), this file would help you to login to your server instance and perform SFTP.
Use Putty or similar SSH client to login to your EC2 server instance created on Step-1 using .pem file and server's public DNS, refer Accessing Instance for SSH login.
Transfer the archived files packed into jar to server using SFTP client, WinnSCP being one such client, refer SFTP for more on it.
Run application. Note in case of jar file you can simply fire java -jar TomcatApp.jar.
If everything is configured properly you would be to access the app using EC2 instance's public DNS or public IP, which would be of the form:
http://<public_dns_address>:<port number>/servlet
Hope it helps you to get started and provide you an overall view.