server - Saas: Single-instance vs Multi-instance vs Single-tenant vs Multi-tenant?

Question

I've been reading about instances and tenants and in the Saas architecture. My questions are as follows (please correct anything that you notice I've gotten wrong with any of the following terms):

1) Instance: Is an instance of a piece of software just a copy of that software with its own database? Is there anything more to it than that?

2) Tenant: Is a tenant a user / group of users that share a common set of access privileges to an individual instance?

3) Single-instance: If a Saas provider offers single-instance service, does this mean that they create only a single instance of their software? Or does it mean that there could be multiple instances, but that each instance can serve multiple tenants? If so, is single-instance the same as multi-tenant?

4) Multi-instance: Does this mean that each instance can serve only one tenant, or can there be multiple instances that each serve multiple tenants? ie. Can a multi-instance service be either single-tenant or multi-tenant?

5) Single-tenant: Does this just mean that an individual instance can serve only one tenant, or does it also imply that there are multiple instances? ie. Can a single-tenant service be both single-instance and multi-instance?

6) Multi-tenant: Does this just mean that an individual instance can serve multiple tenants, or does it imply that there is only a single instance? ie. Can a multi-tenant service be both single-instance and multi-instance?

7) To sum up: Can you have single-instance+single-tenant, single-instance+multi-tenant, multi-instance+single-tenant, and multi-instance+multi-tenant?

标签： servermulti-tenantsaassingle-instancemulti-instance-deployment

Answer 1

我将根据我的直接经验来写：

1）简单的答案是“是”。

2）几乎是的：可能会有细化的访问权限，比如一两个管理员和普通用户。

3) 他们只为您提供该模块的一个实例，这将是单租户。

4）他们为您提供该模块的多个实例，这些实例将是单个租户。

5) 我会使用单租户来指代托管实例的服务器仅由一个租户使用。这可能是为了感知安全利益，或者服务器运行在 SaaS 提供商非标准的时区，例如全年保持 UTC。

6) 我会使用多租户来指代托管实例的服务器被多个租户使用。这往往更具成本效益，并且可能与单租户一样安全。

7) 是的，不是的，是的，是的。