多个组织的系统设计

Question

At the company I work for, we develop and host a CRM system for multiple organisations where the database is segregated - ie our clients do not share 1 large database similar to Facebook, we have separate databases per client, but the same CRM software. All other system aspects such as caching are organisation specific.

We're migrating our servers onto AWS and this has given us an opportunity to think about the infrastructure.

Our base system is written using the CodeIgniter framework, so we're thinking instead of having multiple instances of the same CRM, creating a single instance and attaching the relevant database credentials depending upon hostname / user account (this method, the CRM would be accessed via a dedicated URL). Eg if user A works for company B, we'll connect to company B's databases and not company C. This example would also help with our versioning control.

I'm just wondering if others have had a similar experience, and whether the general feeling is to keep instances completely segregated or migrate to a true "software as a service" single instance method?

Answer 1

it realy depends on DB sizes and traffic. If you have got a lot of traffic, separate DBs are better as you can easily move them out on to their own server instances if they need more resources + it is easyer to manage. If you don't have a lot of traffic, you can use one DB but that is risky if you need to do something company specific specific. Code wise, a single instance is much easier to maintain because you would not have to roll out changes for every instance individually, and if your server hits capacity, simply slap on a load balancer and spin up more instances of the same webserver ()keep in mind DBs should be on separate server/s.

Answer 2

The author of this thread already accepted proposal as answer. However, I recommend you to read on multi-tenant architecture which will guide you more. Here you could associate individual companies as tenants.

• Msdn
• Wiki

Answer 3

There are several important considerations in choosing a multi-tencancy or single-tenancy architecture, including:

• Security - can you effectively segregate data, access, permissions etc. in a multi-tenancy environment?
• Infrastructure costs - will you be able to effectively utilise server/platform capacity with a single tenants? On AWS, scaling can help with this.
• Licensing costs - are there significant additional license costs in a single-tenanted environment (normally more servers means more licenses)?
• Effort/cost to implement and maintain - will a single-tenant solution require significantly more effort to manage deployments and maintain the infrastructure?