Synchronization of calls in progress with new Backup SIP Server
Iteration 110. FDS: https://intranet.genesys.com/display/RDSIPS/%5BFDS%5D+Synchronization+of+calls+in+progress+to+new+Backup+SIP+Server
Impacted pages:
- https://docs.genesys.com/Documentation/SIPS/8.1.1draft/HADeployment/RedundancyTypes#Hot-Standby_Redundancy_Type
- https://docs.genesys.com/Documentation/SIPS/8.1.1draft/HADeployment/ConfOptionsHA
- https://docs.genesys.com/Documentation/SIPS/8.1.1draft/HADeployment/NewInThisRelease
When Backup SIP Server restarted or HA link connection between Primary and Backup lost for some period of time, and then re-established, some calls would only exist on Primary SIP Server. Previously SIP Server would not synchronize such calls and in case of failover they would be lost. This feature addresses this issue. Primary and Backup SIP Servers, after establishing HA link connection, will exchange information about calls and trigger synchronization of missing calls to Backup SIP Server. This will ensure those calls are preserved in case of failover or switchover. Current limitation is multisite calls. Information about ISCC links between parties on different SIP Server HA pairs not synched during HA link connected. As result for such call ISCC functionality, in case of immediate Switchover, could be broken. The synchronization of new calls will happen right after HA link established. Immediate switchover or failover after HA Link connected should be considered as double failure.
SIP Server reports its readiness to upgrade and switchover over its web interface:
SIP Server application option http-port has to be configured on application level. Web Interface can be accedes using http://<SIPS_HOST>:<HTTP_PORT> Readiness to upgrade and switchover available in "Sip Server" section:
Reliable upgrade procedure of SIP Server HA pair:
- Check SIP Server in Backup role for readiness to upgrade via web interface
- Stop SIP Server running as Backup. Install new version and start again.
- Check Primary and Backup SIP Servers for readiness to switchover via web interface and initiate switchover if readiness is 1.
- Check SIP Server in Backup role for readiness to upgrade via web interface
- Stop SIP Server running as Backup. Install new version and start again.
ha-max-calls-sync-at-once
Section Name: TServer, Application level
Default Value: 500
Valid Values: 200-1000
Changes Take Effect: When HA link connection is established
Specifies the maximum number of calls that can be synchronized at once from the former primary SIP Server to the new primary SIP Server (the former backup) after the HA link connection is established, before waiting for 1 second to continue (with synchronization?). Only calls that are missing on the former backup SIP Server are synchronized. This option enables to throttle synchronization of calls in case of a slower network connection between primary and backup SIP Servers.
Feature Limitations
In case of multi-site call, information about ISCC links between parties on different SIP Server HA pairs not synced during HA link connected. As result for such call ISCC functionality, in case of immediate Switchover, could be broken. Complicated multi-site call flows which include OOSP transfers can result in a TEP-only (transit) call. Such calls exist only to propagate T-Events and updates between other sites, maintaining integrity of a multi-site call. Such call doesn't have TSCP/DDP counterparts. Thus, such transit calls will not get replicated to backup server after Backup SIP Server restart or reconnect
