Chapter 1 Product Overview 9
Dynamic Reconfiguration and High Availability
The Sun Crypto Accelerator 4000 hardware and associated software providesthe
capabilityto work effectively on Sun platforms supporting Dynamic Reconfiguration
(DR) and hot-plugging. During a DR or hot-plug operation, the Sun Crypto
Accelerator 4000 software layer automatically detects the addition or removal of a
board and adjusts the scheduling algorithms to accommodate the change in
hardware resources.
For High Availability(HA) configurations, multiple Sun Crypto Accelerator 4000
boards can be installed within a system or domain to insure that hardware
acceleration is continuously available. In the unlikely event of a Sun Crypto
Accelerator 4000 hardwarefailure, the software layer detects the failure and removes
the failed board from the list of available hardware cryptographic accelerators. Sun
Crypto Accelerator 4000 adjusts the scheduling algorithms to accommodate the
reduction in hardware resources.Subsequent cryptographic requests are scheduled
to the remaining boards.
Note that the Sun Crypto Accelerator 4000 hardware provides a source for high-
quality entropy for the generation of long-term keys. If all the Sun Crypto
Accelerator 4000 boardswithin a domain or system are removed, long-term keys are
generated with lower-quality entropy.
Load Sharing
The Sun Crypto Accelerator 4000 software distributes load across as many boardsas
are installed within the Solaris domain or system. Incoming cryptographic requests
are distributed acrossthe boards based on fixed-length work queues. Cryptographic
requests are directedto the first board, and subsequent requests stay directed to the
first board until it is running at full capacity.Once the first board is running at full
capacity,further requests are queued to the first board available that can accept the
request of this type. The queueing mechanism is designed to optimize throughput
by facilitating request coalescing at the board.