The redundant line control function provides a high-reliability communication infrastructure that supports continuous transmission in the event of a network path or card failure by making transmission routes redundant with multiple NIC (Network Interface Cards).
GLS enables the following four network control methods. For details on the virtual NIC mode, see "PRIMECLUSTER Global Link Services Configuration and Administration Guide 4.3: Redundant Line Control Function for Virtual NIC Mode."
In Fast switching mode, a redundant transmission route between Solaris servers or Linux servers in the same network is used so that the total amount of data transferred can be increased, and that the data communication can be continued even if the transmission route fails. It also enables higher levels of throughput through redundant transmission routes. GLS performs early failure detection, so when one transmission route fails, the failed route will be cut off then the system will be operated on a reduced scale. The compatible hosts are SPARC M10, SPARC Enterprise, PRIMEPOWER, GP7000F, Fujitsu S series, GP-S, PRIMERGY, and PRIMEQUEST.
Note that fast switching mode cannot be used to communicate with hosts on the other networks beyond the router.
Figure 1.1 Fast switching mode
In NIC switching mode, redundant NICs (LAN cards) are connected to each other on the same network and used exclusively. If one transmission route fails, ongoing communications will be switched to the other transmission route. There are no restrictions on remote systems to communicate with.
Note that NIC switching mode can be used to communicate with any hosts on the other networks beyond the router.
Figure 1.2 NIC switching mode
Virtual NIC mode provides a high-reliability communication by grouping multiple network interfaces on the same network as one virtual interface. If one transmission route fails, ongoing communications will be switched to the other transmission route. There are no restrictions on remote systems to communicate with. When comparing the virtual NIC mode to the NIC switching mode which makes network interfaces on the same network redundant, there are the following features:
Specifying IP addresses to be monitored is unnecessary by the fault monitoring function.
In Solaris Zones environments, the virtual NIC is available from not only a global zone but also a non-global zone.
In Oracle VM environments, the configuration where virtual interfaces connect to virtual bridges is available.
Figure 1.3 Virtual NIC mode
GS/SURE linkage mode enables the system to control lines by using a Fujitsu method for high-reliability communication between the system and Global Server or SURE SYSTEM. In this mode, duplicated lines are used concurrently. During normal operation, lines are automatically assigned to each TCP connection for communication. In the event of a fault, the system disconnects the faulty line and operates on a reduced scale by moving the TCP connection to the normal line. This mode provides the following connection functions (Hereafter, GS refers to Global Server and SURE refers to SURE SYSTEM).
