170 research outputs found
ATP: a Datacenter Approximate Transmission Protocol
Many datacenter applications such as machine learning and streaming systems
do not need the complete set of data to perform their computation. Current
approximate applications in datacenters run on a reliable network layer like
TCP. To improve performance, they either let sender select a subset of data and
transmit them to the receiver or transmit all the data and let receiver drop
some of them. These approaches are network oblivious and unnecessarily transmit
more data, affecting both application runtime and network bandwidth usage. On
the other hand, running approximate application on a lossy network with UDP
cannot guarantee the accuracy of application computation. We propose to run
approximate applications on a lossy network and to allow packet loss in a
controlled manner. Specifically, we designed a new network protocol called
Approximate Transmission Protocol, or ATP, for datacenter approximate
applications. ATP opportunistically exploits available network bandwidth as
much as possible, while performing a loss-based rate control algorithm to avoid
bandwidth waste and re-transmission. It also ensures bandwidth fair sharing
across flows and improves accurate applications' performance by leaving more
switch buffer space to accurate flows. We evaluated ATP with both simulation
and real implementation using two macro-benchmarks and two real applications,
Apache Kafka and Flink. Our evaluation results show that ATP reduces
application runtime by 13.9% to 74.6% compared to a TCP-based solution that
drops packets at sender, and it improves accuracy by up to 94.0% compared to
UDP
CoRD: Converged RDMA Dataplane for High-Performance Clouds
High-performance networking is often characterized by kernel bypass which is
considered mandatory in high-performance parallel and distributed applications.
But kernel bypass comes at a price because it breaks the traditional OS
architecture, requiring applications to use special APIs and limiting the OS
control over existing network connections. We make the case, that kernel bypass
is not mandatory. Rather, high-performance networking relies on multiple
performance-improving techniques, with kernel bypass being the least effective.
CoRD removes kernel bypass from RDMA networks, enabling efficient OS-level
control over RDMA dataplane.Comment: 11 page
Managing NFV using SDN and control theory
Control theory and SDN (Software Defined Networking) are key components for NFV (Network Function Virtualization) deployment. However little has been done to use a control-theoretic approach for SDN and NFV management. In this paper, we describe a use case for NFV management using control theory and SDN. We use the management architecture of RINA (a clean-slate Recursive InterNetwork Architecture) to manage Virtual Network Function (VNF) instances over the GENI testbed. We deploy Snort, an Intrusion Detection System (IDS) as the VNF. Our network topology has source and destination hosts, multiple IDSes, an Open vSwitch (OVS) and an OpenFlow controller. A distributed management application running on RINA measures the state of the VNF instances and communicates this information to a Proportional Integral (PI) controller, which then provides load balancing information to the OpenFlow controller. The latter controller in turn updates traffic flow forwarding rules on the OVS switch, thus balancing load across the VNF instances. This paper demonstrates the benefits of using such a control-theoretic load balancing approach and the RINA management architecture in virtualized environments for NFV management. It also illustrates that GENI can easily support a wide range of SDN and NFV related experiments
Replicating Persistent Memory Key-Value Stores with Efficient RDMA Abstraction
Combining persistent memory (PM) with RDMA is a promising approach to
performant replicated distributed key-value stores (KVSs). However, existing
replication approaches do not work well when applied to PM KVSs: 1) Using RPC
induces software queueing and execution at backups, increasing request latency;
2) Using one-sided RDMA WRITE causes many streams of small PM writes, leading
to severe device-level write amplification (DLWA) on PM. In this paper, we
propose Rowan, an efficient RDMA abstraction to handle replication writes in PM
KVSs; it aggregates concurrent remote writes from different servers, and lands
these writes to PM in a sequential (thus low DLWA) and one-sided (thus low
latency) manner. We realize Rowan with off-the-shelf RDMA NICs. Further, we
build Rowan-KV, a log-structured PM KVS using Rowan for replication. Evaluation
shows that under write-intensive workloads, compared with PM KVSs using RPC and
RDMA WRITE for replication, Rowan-KV boosts throughput by 1.22X and 1.39X as
well as lowers median PUT latency by 1.77X and 2.11X, respectively, while
largely eliminating DLWA.Comment: Accepted to OSDI 202
- …