# How to setup Single Application and multiple customers/db **URL:** \ **Category:** Deployment\ **Created:** [December 20, 2007, 11:19pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824 "2007-12-20T23:19:22Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [December 20, 2007, 11:19pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/1 "2007-12-20T23:19:22Z")
Hi All, I have an rails application which is designed to connect to one db and work at 1 url. Let say i want to host it 10 customers like [http://customer1.coolapp.com](http://customer1.coolapp.com) -\>customer1 db [http://customer2.coolapp.com](http://customer2.coolapp.com) -\>customer2 db [http://customer3.coolapp.com](http://customer3.coolapp.com) -\>customer3 db … [http://customer10.coolapp.com](http://customer10.coolapp.com) -\>customer4 db What is the best way to deploy the application? Option 1: have multiple code trees for each customer and thus each customer having his own rails app and use apache/lighttpd to route the requests much like [http://duncandavidson.com/archives/154](http://duncandavidson.com/archives/154) Option 2: have a single code tree and depending upon the request url, connect to the appropriate database, much like [http://wiki.rubyonrails.org/rails/pages](http://wiki.rubyonrails.org/rails/pages) … Databases. I will have some customer specific datafiles. Which of the approaches is a scalable and maintainable, for lets say 100-1000 customers. Thanks in Advance. ---
**Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [December 28, 2007, 1:52am UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/2 "2007-12-28T01:52:38Z")
For me, I would add customer\_id in the tables, and make sure that one “customer” only could see his data. Then you can easily scale. Also just let the “customer” login. There “record” will tell you who they are, and you can go from there. You can also do the different dns names, but dns’s are a pain, and also take a while to populate. Also that means you can have a single mongrel\_cluster, and a nginx proxy to handle the whole mess. Otherwise you memory usage is going to get interesting. Did something similar for a network management application I’ve done before. On Dec 21, 6:19 am, Giridhar Tatavarty \ **Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [January 2, 2008, 9:15pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/3 "2008-01-02T21:15:14Z") Thanks for the reply. The solution seems interesting but I already have the tables and the application setup without the customer\_id, so it would take a significant effort to go change the working application. Is there any plug-in / Active record hacks which will do it easily. ---
**Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [January 3, 2008, 7:30am UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/4 "2008-01-03T07:30:10Z")
Actually its pretty easy to add the fields using migrations. Since you probably only have 1 or two customers at this point. Really promise you your going to regret it other ways. Also the “customer” id is hiden in most in your “views”. On Jan 3, 4:15 am, Giridhar Tatavarty \ **Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [January 3, 2008, 4:43pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/5 "2008-01-03T16:43:16Z") Hello, I don’t think it would be that hard to add in the customer id application wide if you changed things at the model or application level. The concern I would have is performance/privacy issues with all of the data in the same location. On the other hand, I would just try to lockdown the application security wise and use the same db. That way you can take advantage of mysql clustering [http://www.mysql.com/products/database/cluster/](http://www.mysql.com/products/database/cluster/) when your app gets large enough. It’s a scaling issue that rails will have to deal with more and more, but I’m confident that it would be mmore manageable for now to setup a customer\_id key in your fields than to deal with the extra database complexity. -ht On Jan 2, 2:15 pm, Giridhar Tatavarty \ **Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [January 10, 2008, 3:48pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/6 "2008-01-10T15:48:29Z") Thank you Vitaly, Hugh and glennswest, for taking time to answer my question. I think both the solutions are attractive and have their advantages and disadvantages. It appears that application stability and privacy issues are very critical so i am leaning towards the solution of Vitaly Kushner and implement a scheme which serves different db, depending upon url. I agree with glennswest that dns is pain and testing such setup is also very complication and i cannot test on my localhost easily such as customer1.localhost or customer2.localhost etc . Once, i implement i would post my results. Once again i thank everyone for their comments. ---
**Author:** ![tgiridhar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/858c86/32.png) [@tgiridhar](https://www.ruby-forum.com/u/tgiridhar)\ **Post date:** [January 7, 2008, 11:20pm UTC](https://www.ruby-forum.com/t/how-to-setup-single-application-and-multiple-customers-db/123824/7 "2008-01-07T23:20:53Z")
Giridhar Tatavarty wrote: > Hi All, > > I have an rails application which is designed to connect to one db and > work at 1 url. Let say i want to host it 10 customers > > like > > [http://customer1.coolapp.com](http://customer1.coolapp.com) -\>customer1 db > [http://customer2.coolapp.com](http://customer2.coolapp.com) -\>customer2 db > [http://customer3.coolapp.com](http://customer3.coolapp.com) -\>customer3 db > … > [http://customer10.coolapp.com](http://customer10.coolapp.com) -\>customer4 db > > What is the best way to deploy the application? > Option 1: have multiple code trees for each customer and thus each > customer having his own rails app and use apache/lighttpd to route the > requests much like [http://duncandavidson.com/archives/154](http://duncandavidson.com/archives/154) > > Option 2: have a single code tree and depending upon the request url, > connect to the appropriate database, much like > [http://wiki.rubyonrails.org/rails/pages](http://wiki.rubyonrails.org/rails/pages) … Databases. > > I will have some customer specific datafiles. > > Which of the approaches is a scalable and maintainable, for lets say > 100-1000 customers. > > Thanks in Advance. The answer depends on the exact circumstances, but in case of an existing application I think it is much better to go with a single application tree serving from DIFFERENT databases. i.e. have some filter choose database per customer. you will have to juggle some active record connections (and keep them alive etc.) but it will be much easier then going though the whole application ensuring that the data can not ‘leak’ from one customer to another. In a real-world non trivial application of a substantial size you usually have custom sql, performance hacks, page caches etc that might cause the leaks and depending on the problem domain it might not be an acceptable risk. BTW, the leak by cached pages is something you will have to deal with anyway. You need to define fragment cache path (if you use file store) depending on the customer. and if you want page caching, you will need to configure separate web server root per customer. i.e. in apache, you will have to define separate virtual host per customer with a separate cloned ‘public’ directory as a root dir, all proxying dynamic requests to the same mongrel cluster for example. Same with per-customer data files. just put them in separate directories and define current customer directory per request.