Efficient Measurement on Programmable Switches Using Probabilistic Recirculation

Abstract

Programmable network switches promise flexibility and high throughput, enabling applications such as load balancing and traffic engineering. Network measurement is a fundamental building block for such applications, including tasks such as the identification of heavy hitters (largest flows) or the detection of traffic changes.However, high-throughput packet processing architectures place certain limitations on the programming model, such as restricted branching, limited capability for memory access, and a limited number of processing stages. These limitations restrict the types of measurement algorithms that can run on programmable switches. In this paper, we focus on the RMT programmable high-throughput switch architecture, and carefully examine its constraints on designing measurement algorithms. We demonstrate our findings while solving the heavy hitter problem.We introduce PRECISION, an algorithm that uses Probabilistic Recirculation to find top flows on a programmable switch. By recirculating a small fraction of packets, PRECISION simplifies the access to stateful memory to conform with RMT limitations and achieves higher accuracy than previous heavy hitter detection algorithms that avoid recirculation. We also analyze the effect of each architectural constraint on the measurement accuracy and provide insights for measurement algorithm designers.

Programming Protocol-Independent Packet Processors High-Level Programming (P4HLP): Towards Unified High-Level Programming for a Commodity Programmable Switch

“…The E-Domino can implement various data plane algorithms. Except for the space saving algorithm, which is not feasible on the state-of-art hardware, we implement the other algorithms (Bloom filter [12], Flowlet [13], HashPipe [15], RAP [16], PRECISION [10], Elastic sketch [17] and SketchLearn [18]) in E-Domino and then transform them into P4 programs using P4HLPc. The P4 programs use different atoms.…”

“…We present the design of E-Domino, taking the PRECISION [10] heavy hitter detection algorithm as an example, as shown in Algorithm 1. PRECISION measures the size of flows with the key-value pair register Key i and Val i .…”

“…Although P4 (Programming Protocol-Independent Packet Processors) [9] provides abstractions for the data plane, switch chips put tight restrictions on P4 programming [10,11]. These restrictions can be on processing resources, storage resources, and latency; programmers can declare arbitrary numbers and combinations of the P4 hardware primitives; the programmers must handle read/write dependencies when using storage resources, and they must pay attention to latency restrictions to guarantee line-rate processing; in addition, manufacturers tailor P4 specifications for their architectures, putting even more restrictions on P4.…”

“…In this paper, we choose three types of network algorithms: (i) The basic algorithms which implement the single task and can be used as modules of other algorithms, e.g., the Bloom filter [12] and Flowlet [13]. (ii) The Heavy Hitter (HH) detection algorithms, e.g., SpaceSaving [14], HashPipe [15], Randomized Admission Policy (RAP) [16], and Probabilistic RECirculation admisSION (PRECISION) [10]. (iii) The network telemetry systems which are general-purpose algorithms, e.g., ElasticSketch [17] and SketchLearn [18].…”

MV-Sketch: A Fast and Compact Invertible Sketch for Heavy Flow Detection in Network Data Streams

“…MV-Sketch achieves line-rate measurement with limited resource overhead. It also achieves higher accuracy and smaller resource usage than PRECISION [7] (a heavy hitter detection scheme in programmable switches). See Section VI.…”