Graceful rollover

Staring with Release 8.1.400.37, URS simplifies the process for moving call processing from one URS instance to another URS. Once a working or active primary/backup pair of URSs exists, URS automatically performs all necessary steps for a graceful rollover using those relationships.

How It Works

When a graceful rollover starts, Management Layer still sees the primary/backup pair relationship between the two URSs, but internally those URSs turn into a cluster of two independent URSs, which can stop to execute the graceful rollover commands.

Prerequisites

The prerequisites for a graceful rollover are as follows:

• A primary/backup URSs must be configured and work. Graceful shutdown is not applicable for single (backup less) URS instance.
• Genesys recommends configuring agent reservation before using graceful rollover since the graceful rollover process temporarily turns a primary/backup pair of URSs into a cluster of two independent URSs. For more information, see the agent_reservation option in the Universal Routing 8.1 Reference Manual.
• If Orchestration Server backed-up calls are present, verify that the current backup URS is aware of all such calls. To verify, send a web request to the primary URS: urs/console?backup. The response should be name(host:port,socket);000000000000. The presence of a non-null connection ID after the semicolon indicates that it is not safe to start the rollover process as some ORS backed-up calls could be lost.

Graceful Rollover Command

You can start graceful rollover with any of the following:

• A web request to the current primary URS: urs/console?rollover
• The console command rollover
• The Local Control Agent command Suspend (Graceful Stop)

Web request

When URS receives a graceful rollover command by web request:

The current primary URS

• stops processing of new interactions (from T-Servers or Web clients).
• stops processing of any multimedia calls (returns them to Ixn queues) and ORS backed-up calls.
• imitates switching into backup mode of operation, forcing ORS (if any) to switch to current backup node.

The current backup URS

• deletes all interactions (as they all will be processed by the current primary node) except for the ORS backed-up interactions.
• switches into primary mode of operation and starts processing new interactions as they arrive.

When the original primary finishes processing all existing calls, it automatically exits.

Console command

When graceful shutdown is started with the console rollover command:

• if no backup is configured then URS replies with no backup and does not start the graceful shutdown procedure; if URS has no connection with its backup then URS will reply with no connection and will not start graceful shutdown procedure.
• URS replies with the name of its backup server and starts the graceful shutdown procedure.

LCA command

When graceful shutdown is started through LCA, URS ignores the request if no proper backup exists. Effectively it results in an ungraceful shutdown, as in such cases SCS requests that the application quit.