Altering Endpoints When You Use SOAP Sessions
When SOAP sessions are running over an HTTP endpoint, changes to that endpoint can affect the state of current sessions for that endpoint. Generally, changes to an endpoint can be categorized under the following main categories:
Changes to HTTP properties
Because this affects all HTTP connections to the endpoint, any subsequent use of an existing session or new sessions will be affected.
Change to global properties
These occur when the state of the endpoint changes, such as either started or stopped. As with HTTP properties, any changes to global properties will affect subsequent use of existing sessions or any new sessions initiated on the endpoint.
Change to SOAP properties
Because endpoint metadata is cached per each endpoint, changing SOAP properties such as WEBMETHOD, SCHEMA, or WSDL optional settings will affect current sessions.
Basically, executing any ALTER ENDPOINT statement will cause the endpoint to be invalidated. Because all session operations must occur on the same endpoint, this means that executing any ALTER ENDPOINT statement will end any open sessions on that endpoint.