Spring Multi-Tenancy - Adding new tenant without restart (using AbstractRoutingDataSource) - java

I'm implementing a multi-tenant system using Spring where each tenant has its own database. I have everything up and running.
I've extended "AbstractRoutingDataSource" and overridden "determineCurrentLookupKey" to determine which connection to use via the users domain/tenancy.
The "AbstractRoutingDataSource" is instantiated when the app loads and all the possible database connections are set there.
Here's my question -
Is there a way of dynamically adding additional connections to the AbstractRoutingDataSource? I want to be able to add additional tenants without restarting.
Any help would be greatly appreciated
Thanks

I am too late to this thread, but recently I needed to build a Saas style multi-tenant web app. Tenants needed to be added dynamically without requiring a server restart. So I shared my learnings here with a complete working example.

Yes You can do So, Here is complete project which explains very nicely about your requirement:
Multi-tenancy: Managing multiple datasources with Spring Data JPA

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Integrating Hibernate to Spring running on embedded jetty

I have just returned to Spring after 5 years of gap and it seems lot is changed. I have a task to create a REST Service using Spring with hibernate as an ORM, So far I am able to run a basic Rest Service using embedded jetty and able to make GET/POST calls, the next is to integrate hibernate into it so that the data fetch/Sent operation actually use MySQL instead of sending hard-coded response(which I have done currently).
The issue is earlier I used to work on Spring MVC using Tomcat where we had web.xml to define the dispatcher servlet and application-context which in turn were used to define hibernate config and other beans declaration, but now having embedded jetty I am not finding a way to integrate hibernate to my REST app, Is the way to add configuration is changed from XML to class based config. I searched over internet but maybe I am out of words or not using correct keywords, in short, Have no luck finding some solution to integrate hibernate to my Spring app which is using embedded jetty.
Could some please breif me about the recent changes or point me to the right tutorial ?
Any help appreciated, thanks in advance !
ps - I have used this example to progress so far https://github.com/pethoalpar/SpringMvcJettyExample
Yes , lot of changes in these 5 years and one of the game-changer is spring-boot
If you want to build a brand new project especially if you want to run the web application on the embedded container such as Jetty , you can check out spring-boot.It already provides integration with Jetty , hibernate and Spring MVC REST service.
The end result is that you just need to change a little bit configuration (most probably the DB connection info) and you can quickly get a production-ready REST service backed by JPA/Hibernate which can just run without any XML configuration anymore.
There are tons of tutorials in Internet talking about how to do it . You should easily find them out such as this using the keywords something likes "springboot webservice hibernate jetty" etc.

Hibernate database (maria-db) change detect

I need to understand, Is there anyway I can continuously look for change in Maria-DB table using Hibernate.
I have a spring boot application that is connected to Maria-DB. If some other application perform CURD on table, I want to catch that in spring.
If it's not possible using hibernate, suggest me alternative.
PS : This spring boot application is running is different Docker Container and Maria-DB is running is different Docker Container.
You can use Database Triggers, or better why don't you try enabling Hibernates 2nd level cache?
Solution to this specific problem is Spring Integration module as other ways not working here. I have create a sample application to demonstrate here you can find the source code
What this application does look database continuously.

Multi-Tenant and Central Database with Spring Boot and Hibernate

Specification
Each tenant has their own database which handles users in greater detail, and there needs to exist a central database which handles:
Tokens (OAuth2)
Users (limited level of detail)
Mapping users to their database
Problem
I've found solutions for multi-tenancy which allows me to determine the datasource depending on the user. However, I'm not sure how I can also link certain crud repositories to this central datasource, and others to variable datasources.
Another solution involved updating the properties file, and using a configuration server (i.e. via git) to trigger #RefreshScope annotated configs. Though I'm not sure if this can work for Datasources, or if this could cause problems later on.
Extra Context
I'm using Spring Boot and Hibernate heavily in this project.
This blog gives a very good tutorial on how to do it.
After a lot of research it looks like hibernate just isn't built for doing that, but by manually writing the schema myself I can inject that into new tenant databases using native queries.
I also had a problem with MS Server DBs, as they don't allow simply appending ;createDatabaseIfNotExist to the JDBC URL, which meant even more native queries (Moving the project over to use MySQL anyway, so this is no longer a problem.)

Multi tenancy with Spring boot

I'm planning to work on a multi-tenancy application and for now I'm just looking at different implementations on the web to understand the requirements needed to implement such task.
Hibernate + Spring boot are the technologies I'm planning to use.
From my readings, all the different tutorials are using the same approach which is to declare the data sources in a config file so that session factories are launched with the boot of the application, but I really want to have a higher level of the app, where I can add tenants dynamically and input their data sources informations.
This way the application can get the information of the new tenant without the need to touch the config files and re-boot the app.
I thought about having a separate database where I can store my tenants data source credentials or something like that. Can you give me another approach to solve this requirement or a link to an existing implementation that I can refer to.
Thanks
I got similar requirements in the past.
I implemented DataSource proxy class. The class has tenant resolver and a map of simple DataSources. All the places where we need a DataSource use the proxy.
On any method call e.g. getConnection() it resolves tenant, check whether the map contains already created DataSource (if not a new DataSource is created for the tenant and stored in the DB). Then the same method of real DataSource from the map is invoked.
Tenant resolver is ThreadLocal based where tenant value is stored in a filter (got tenant from request header) and used in the DataSource proxy.
What you need to do is using dynamic datasource routing of Spring Framweork via AbstractRoutingDataSource. This answer explains all for you.
In my question.I implements MultiTenantConnectionProvider and CurrentTenantIdentifierResolver.And use DataSourceLookup to choose datasource by tenant.This links is helpful to me.
Here is a full working example of a database-per-tenant multitenat app I built using Spring Boot 2, Spring JPA (Hibernate), Spring Security 5 running on MySQL.
I have explained how it all works and have shared the entire code too.
Take a look here.

Using Spring, JPA with Hibernate to access multiple databases/datasources configured in Jboss

I have a requirement where i need to configure a Spring based application to work with two databases. We have two databases, one that we use to keep the live data and the other database is used as a datawarehouse and contains archived data (which has the exact structure as the Live db).
To keep it simple, assume that there is a request to search for a product. What the application should do is to search for the product details in the Live database and if not found it will check the archive database.
If i need to configure such a setup, do i still need to configure to datasources and would the search code have to use the first datasource to check the live database and if not found it will run another query using the archive database?
The above is probably doable but i am wondering whether there is a better way of doing this. For example, is it possible for the application to work on a single datasource even though behind the scenes it actually works with two databases?
The application is based on Spring, JPA/Hibernate, SOAP and Mysql database and Jboss 7 as the application server.
Any examples showing how this is configured using Spring and Jboss would be very useful.
Thanks
Spring has exactly what you want - the AbstractRoutingDataSource. See this blog post on how to use it. In your case, you need to switch the datasource during one request, so you'll need to have 2 transactions, switching the datasource between them by changing the datasource indicator on the ThreadLocal:
For these DAOs, demarcate the wrapping Service-layer either with distinct packages, class names, or method names
Indicate to Spring that the Service-layer method calls should run in their own transactional contexts by annotating with #Transactional(propogation=Propogation.REQUIRES_NEW)
Create an Aspect (using AspectJ annotation #Aspect) to fire around the service-layer method calls (using #Around) to set the ThreadLocal value before the method call, and to unset it afterwards
In the #Controller, simply call the Service-layer methods. The Aspect will take care of setting the values to indicate which datasource to use, and the AbstractRoutingDataSource will use that datasource in the context of each transaction.

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