I have a java webapp using hibernate over MYSQL db. I need at least an hour of data maintenance daily, hence I need to bring down the db and switch to the backup db.
I don't see an elegant way to switch to another db from my app using hibernate. Is there?
Other totally different ways for database maintenance is welcome.
As you are using a Java WebApp, I assume you are using a container (like Tomcat) or an application server (like JBoss). In both cases, you should be using managed connections by the container, via JNDI. In such case, you can just use JMX (or the admin console) to change the actual datasource, to point to the backup DB, clean the pool and reopen new connections. When you are done, just perform the same steps, pointing the datasource to the actual database.
If you are not using managed connections by the container, you are out of luck. As the Hibernate configuration is static, you'll need to bring down your app, deploy a new version of it with your persistence.xml/hibernate.cfg.xml pointing to the backup, do the maintenance, and deploy the "old" version when you are done.
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I'm running optaweb-employee-rostering in a dockerized Wildfly server, persisting data with MySql database running in a container too. The .war file is not built in sever's Docker image, it's manually deployed in it via Wildfly's admin interface. Every time container is stopped a restarted, the application rebuild sample data, deleting any data saved during usage, so that the final behavior is the same as ram based storage: the data is lost if the server stops.
Is there a way to avoid this behavior and keep saved data on server restart?
This is caused by the hbm2dll value here and due to the Generator's post construct. In the current openshift image there are environment variables to change that.
We're working on streamlining this "getting started" and "putting it into production" experience, as part of the refactor to react / springboot.
I have just completed a Spring Boot tutorial of 34 videos. Im looking online and everything seems to show me how to create persistence of my data when the spring application is running. However, once I stop the program and restart it, it doesn't have the data I want saved.
So what it sounds like is I need to store this information on a database. I think I've set up a MySql server on my laptop and I have the workbench app/interface.
What might be more appropriate is connecting to an online server that I have with phpmyAdmin. In any case, how do I connect my spring application to a database instead of to a localhost:8080
Please let me know where I can look and what resources I have here as I'm kind of new to this sort of thing. Much appreciated!
There 2 options
Either use persistent DB instead of in-memory storage
You are using spring.jpa.hibernate.ddl-auto=create-drop hibernate property that will recreate db schema every time you start the application - thus its "clear" of the start. Use update or validate instead.
Maybe you can set spring.sql.init.mode=never to not always initialize your database using scripts.
This way you'll find all data you saved even when re-run the app.
I am working on a JAVA web application and i have mysql as my backend. I make DB calls from my application. But whenever i make any change in DB, my local server has to be restarted to redeploy my java EAR for the updated DB changes to be reflected, Is there a way i can get the updated DB changes without restarting my local server?
Please let me know.
You don't need to restart your local server unless and until you want to change the database mean you want to point to entirely different database schema.
And if you want to change i.e adding extra columns to the database then also it will work fine but if you delete columns or table from current schema then only you need to change your code and start your server again.
Note :-
In case if you are working with Dynamic Web Project in eclipse with Tomcat server configured within then you don't need to do that also because server will reload your project after some time automatically.
I am working at a company that has some CRM software running in a remote Windows XP server that uses a SQLAnywhere 9 db to store its data; I have access to this remote server with an administrator account.
I would like to extract the db into a .sql file so that I can run the db locally on my machine without affecting the running db in the server (since it is key for the company's day to day operation).
The reason I need this is that we are going to test some BI Software and we need data from this database to test it, but we don't know the structure of the database since the developers of the CRM software didn't give us any documentation on it. So we need to have the database locally so that, without affecting the running CRM, we can:
understand the structure by looking at the DDL
make queries to it to get sample data
I researched a bit, and the most common solution to my problem was to use dbunload on the remote server to unload the db into a reload.sql file that contained what I needed. But most tutorials on the subject mention that I have to stop the db first (which would be catastrophic). If this is the only option, then I guess I am willing to do it on the weekend when the CRM is not used, but I wanted to know if there was another solution first.
If there is no other solution, can you point me to where I can find the proper and safer way to do this?
I have researched a lot, but prior to this day I have never even heard of SQLAnywhere, so I really need all the help I can get. My main concern is doing something that impacts negatively the CRM software.
Thank you.
You can run dbunload across the network, you just have to tell it to do an "external" unload. The default is to do an internal unload which would only work from the machine where the database server is running.
I don't have SQL Anywhere 9 documentation right now to look up the exact switch, but dbunload -? should show you all the possible switches.
Edit:
-an will create a new database and load the data and schema from another data
-xi switch will do external unload and internal reload.
-c parameters to connect to your remote database
I have a situation where I would like a desktop application to be useable whether an internet connection is present or not.
I have a choice of MySQL on a web server and I could work with a local MySQL database or maybe MS Access database on the local drive and then just update data when connection is restored. My issues are as follows.
Sync local changes to remote server. Multi site / multi user scenario so how to keep db in sync when connection restored without loosing changes from other users in server data.
Sync remote changes to local. Multi site / multi user scenario so how to keep db in sync when connection restored without loosing changes made locally while updating with server data.
Currently I am using XML files and LingtoXML querying but it is unsatisfactory to continue with these files so a better solution is required.
Any help would be appreciated to identify what technology would work best and how to keep them in sync.
Thanks in Advance.
"Jet Replication Objects (JRO)", the replication features of the Access Database Engine, have been deprecated (ref: here). I believe that the related management features have also been completely removed from Access 2013. Therefore, native Access replication should no longer be considered a viable option.
Microsoft's recommendation would be to use SQL Server and its replication features. However, SQL Server Express has limitations on how much it can do (e.g., it can be a "Subscriber" but not a "Publisher" or "Distributor", ref: here) so presumably there would have to be a non-free copy of SQL Server involved somehow.
I haven't yet had the occasion to use MySQL replication myself, but it is probably worth considering. Chances are good that you could still use Access as a front-end (via ODBC linked tables).