When failover occurs

Failover occurs when users cannot access the server that contains the database they want or they cannot access the database itself.

The following are potential failover actions and causes:
  • Unable to access server
    • The server is down.
    • There are network connectivity problems.
    • The server has reached the maximum number of users allowed (set with Server_MaxUsers in NOTES.INI).
    • The server is restricted by the administrator (using the Server_Restricted setting in NOTES.INI).
    • The server is BUSY because it has reached the maximum load allowed (the server availability threshold).
  • Unable to access database
    • The database is marked Out of Service in the Cluster Database Directory.
    • The database is marked Pending Delete in the Cluster Database Directory.
When a server or database is not available, failover occurs when a user attempts to use IBM® Notes® to perform certain actions. The following describes the actions that trigger failover.
  • Database open operations
    • Database open operations
    • Opening a database from a bookmark
    • Clicking a document link, a view link, or a database link
    • Using Domain Search when a clustered indexing server is unavailable
    • Accessing roaming files when a clustered roaming server is unavailable
    • Activating a field, action, or button that contains @command ([FileOpenDatabase])
    • Running a LotusScript® routine that contains the OpenWithFailover method of the NotesDatabase class
    • Using Java that contains the OpenDatabase method of the DbDirectory class
    • Replicating with a database on a cluster server that is not running or not reachable on the network
  • Mail and calendar server operations
    • Sending mail
    • Name lookups
    • Type-ahead
    • Routing mail messages
    • Mail predelivery agents
    • Meeting invitations
    • Free time lookups
    • Server lookups
  • Web server operations
    • Selecting the Open URL icon
    • Clicking a URL hotspot
    • Accessing a URL with a Web browser

When failover does not occur

Failover does not occur in the following cases:

  • When a server becomes unavailable while a user has a database open
    Tip: The user can reopen the database, which causes failover to a different replica, if one exists in the cluster. If the user was editing a document when the server became unavailable, the user can copy the document to the replica.
  • When a user chooses File > Application > Properties or File > Application > Open.
  • When the router attempts to deliver mail and mail routing failover is disabled or MailClusterFailover is set to 0
  • When the template server is unavailable while creating a new database
  • When a server fails while running agents, other than the mail predelivery agents
  • When a server fails while running the Administration Process
  • When replicating with a server that is restricted by the administrator or has reached the maximum number of users or the maximum usage level set by the administrator
  • When replicating with a database marked Out of Service