we have a logon group defined, which includes only one instance. Lately it happens that this logon group becomes unavailable for logon. No sessions are broken, only new logons are rejected.
When this happens, in transaction SMLG in Load Distribution, the instance shows response time and number of users 0, and below, where it is shown which instance is currently active for a logon group there is a blank field instead of the instance name.
This is very easily resolved, if we simply click on the instance status above, it gets refreshed, and everything is OK again.
Has anyone had a similar experience, and do you have an idea of what could cause this situatuion?