With a combination of high performance and nonvolatility, the arrival of 3D XPoint memory promises to fundamentally change the memory-storage hierarchy at the hardware, system software, and application levels. This memory will be deployed first as a block addressable storage device, known as the Intel Optane SSD, and even in this familiar form it will drive basic system change. Access times consistently as fast, or faster, than the rest of the system will blur the line between storage and memory. The low latencies from these solid-state drives (SSDs) allow rethinking even basic storage methodologies to be more memory-like. For example, the manner in which storage performance is measured shifts from inputoutput operations (IOs) at a given queue depth to response time for a given load, like memory is typically measured. System changes to match the low latency of these SSDs are already advanced, and in many cases they enable the application to utilize the SSD's performance. In other cases, additional work is required, particularly on policies set originally with slow storage in mind. On top of these already-capable systems are real applications. System-level tests show that applications such as keyvalue stores and real-time analytics can benefit immediately. These application benefits include significantly faster runtime (up to 3× ) and access to larger data sets than supported in DRAM. Newly viable mechanisms for expanding application memory footprint include native application support or native operating system paging, a significant change in the use of SSDs. The next step in this convergence is 3D XPoint memory accessed through processor load/store operations. Significant operating system support is already in place. The implications of consistently low latency storage and fast persistent memory on computing are great, with applications and systems taking advantage of this new technology as storage as the first to benefit.

Network firewalls occupy a central role in computer security, protecting data, compute, and networking resources while still allowing useful packets to flow. Increases in both the work per network packet and packet rate make it increasingly difficult for general-purpose processor based firewalls to maintain line rate. In a bid to address these evolving requirements we have prototyped a hybrid firewall, using a simple firewall running on a network processor to accelerate a Linux* Netfilter Firewall executing on a general purpose processor. The simple firewall on the network processor provides high rate packet processing for all the packets while the general-purpose processor delivers high rate, full featured firewall processing for those packets that need it. This paper describes the hybrid firewall prototype with a focus on the software created to accelerate Netfilter with a network processor resident firewall. Measurements show our hybrid firewall able to maintain close to 2 Gb/sec line rate for all packet sizes, a significant improvement over the original firewall. We also include the hard won lessons learned while implementing the hybrid firewall.

Wormhole routing is an attractive routing technique offering low latency communication without the need to buffer an entire packet in a single node. A new queueing-theoretic model for obtaining throughput and latency of binary hypercubes supporting wormhole routing is developed here. The model is very accurate in predicting the performance of an actual multicomputer over a range of network sizes, packet lengths, and input port priority mappings. Utilizing the model, the performance of networks with identical topologies but different node architectures is estimated.>