How is a salesforce site switch different from an instance refresh ? What is difference in terms of key things we need to check so that they do not impact adversely ?

3 Answers 3


A site switch is used by Salesforce mostly for maintenance and data recovery purposes. This Site Switching Overview knowledge article defines what is a site switch. In case of site switch, you do not lose any of your sandbox metadata or data, Users are just redirected seamlessly to another location without them being aware of behind the scenes activities. You though need to take certain actions to make sure this activity is seamless.

To get more details for faq and actions required for a site switch, refer the knowledge article which details out the topic.

Each Salesforce instance is built and maintained in two geographically separate locations. An instance is actively served from one location (the active site) with transactions replicating in near real-time to the other completely redundant location (the ready site). This infrastructure model allows us to switch the location of the active site for maintenance, compliance, and disaster recovery purposes, which is referred to as a site switch.

An instance refresh completely copies the metadata contents from Production (and data depending on type of sandbox) overriding any contents available in that sandbox. It's just like creating a new sandbox from Production and you lose any unsaved changes in that sandbox.

Refreshing a sandbox updates the sandbox’s metadata from its source org. If the sandbox is a clone or if it uses a sandbox template, the refresh process updates the org’s data in addition to its metadata.


Instance refresh means creating the instance on a new infrastructure so that salesforce can provide its customer latest in hardware.

An instance has many orgs and salesforce does complex capacity calculations and predictive modelling to ensure each org is working at an optimal level. sometimes due to capacity reasons, salesforce can decide to do an instance refresh and split the instance into say 2. for e.g split ap15 into ap100 and ap101. some orgs move to ap100 and some into ap101. they might as well choose to upgrade hardware at same time.

In instance refresh,the instance name will change.

Now let's understand Site Switching.

Every salesforce instance has 2 sites. think of sites as physical locations that are geographically apart. both of these sites are synced in real time. One location is Active (or Primary) and another is called Ready (or secondary).

Active site - currently serving the traffic and transactions Ready site - Replica or backup site.

site switching means switching the roles of active and ready site so that ready becomes Active and active becomes ready. Salesforce does this to ensure disaster recovery and compliance in relation to industry standard DR activities.


One example where a site switch can affect you occurred to our org recently.

  • We went from na30 to na81

Our middleware platform, Boomi, uses hard-coded instance names when you use the Boomi Platform Events feature. That is, Boomi was configured to use https://na30.salesforce.com/... and we had to manually change this to the new https://na81.salesforce.com/...

see related Boomi/SFDC config issue

  • Are you sure it was a site switch and not an instance refresh? Site Switching Overview states that "the instance name does not change". On the Instance Refresh it says "name of your instance will change" Commented Oct 1, 2020 at 10:12

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