- people - netdevconf.info

0x14: nutsnbolts talk, Storage application performance boost with zero thrashing networking stack
by Jamal Hadi Salim 29 Jan '20

29 Jan '20

There has been an ongoing effort in the community to get Zero-copy working over the last few years - with much success. While both MSG_ZEROCOPY (zero copy transmit) and socket mmap (zero copy receive) have been out in the wild for sometime now, there are no known high scale open source application consumers of these interfaces. In this talk, Or Gerlitz will describe how he makes use of these interfaces to integrate into spdk(https://spdk.io/) - an open source storage framework which uses sockets for nvme-over-tcp in a smart NIC environment. The goal is to use kernel uAPIs while achieving high scale performance. Or will delve into MSG_ZEROCPOY and the challenges that he had to deal with. He will describe the need for an app author to understand and how to best tie-in their app state machine to the interfaces: to address both transactions responses from the peer app and zero-copy notifications from the local socket provider. Should the app use ZC with all or nothing approach or sometimes yes and other-times no? Come to the talk to get the answer and advise on how to effectively use these interfaces. In addition Or will spend time going into the performance analysis details correlating I/O performance visavis CPU cost (which is often tricky to get right with traditional tools like profiler/flame-graphs). More info: https://netdevconf.info/0x14/session.html?talk-storage-application-performa… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: nutsnbolts talk, Media Redundancy Protocol
by Jamal Hadi Salim 29 Jan '20

29 Jan '20

MRP(Media Redundancy Protocol) is an open standard for ring topologies in industrial ethernet networks defined in common standards-based protocol(IEC 62439-2). In an MRP-enabled network each Ethernet switch is connected to two other switches forming a ring. An MRP-enabled ring can overcome single link point of failures at worst case recovery time of 30ms - which is faster than STP. In this talk Horatiu Vultur will describe the MRP protocol in some detail. They will then proceed to discuss the effort to add support to the kernel; different implementation approaches considered and eventual implementation path taken after receiving feedback on the mailing list. And last but not least, future work will be discussed including hardware offload of MRP as well as preliminary results comparing hardware-offloaded MRP vs non-offloaded version. More info: https://netdevconf.info/0x14/session.html?talk-adding-MRP-to-the-linux-kern… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: nutsnbolts talk, Extend segment routing for another source routing protocol named RPL
by Jamal Hadi Salim 29 Jan '20

29 Jan '20

RPL is an IPv6 Routing Protocol for Low-Power and Lossy Networks defined in RFC 6550. RFC 6550 defines a mode that is known as "storing" mode. RFC 6554 defines a "non-storing" mode of route propogation. While there are several other RPL open source implementations, they all implement RPL using the "storing" mode which propagates routes via ICMPv6. There are no open source "non-storing" mode implementations. In this talk, Alexander Aring et al will discuss an implementation that uses "non-storing" mode (RFC 6554). In the storing mode(per RFC 6554), route propagation is done via the IPv6 Routing Header. Aring et al discuss the architecture, interface approach, challenges that they overcame and outstanding future work. More info: https://netdevconf.info/0x14/session.html?talk-extend-segment-routing-for-R… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: nutsnbolts talk, Implementation of IPv6 IOAM in Linux Kernel
by Jamal Hadi Salim 28 Jan '20

28 Jan '20

Operations, Administration, and Maintenance (OAM) refers to a set of techniques and mechanisms for performing fault detection, isolation and performance measurements. Classical approaches such are traceroute, ping, etc can now be improved by collecting more granular and precise per-packet telemetry. The IETF is currently in the process of standardizing In-situ OAM (IOAM) to allow collecting operational information along a path. In this talk Justin Iurman et al discuss an implementation of IOAM for the Linux kernel with IPv6 as the encapsulation protocol. They will discuss the details of their approach and demonstrate evaluation results. More info: https://netdevconf.info/0x14/session.html?talk-implementation-of-IPv6-IOAM-… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: Free Range Routing workshop
by Jamal Hadi Salim 28 Jan '20

28 Jan '20

The PC has accepted a new workshop session. Donald Sharp and David Lamparter will chair the FRRouting (https://frrouting.org/) workshop. Current agenda for the workshop includes: * Where to put kernel boundary conventions: * Current Status on netconf/yang models * Status of using kernel nexthop groups FRR * FRR feature rundown: Recent past and future work * Installing FRR for kernel developers For more details: https://netdevconf.info/0x14/session.html?workshop-FRR Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: nutsnbolts talks, Hierarchical Token Bucket
by Jamal Hadi Salim 27 Jan '20

27 Jan '20

Hierarchial bandwith management is a very important packet service for a lot of networking use cases (ranging from large data centres to service provider use cases, etc). Over the last decade, the TC Hierarchical Token Bucket(HTB) qdisc has emerged as the most popular non-work conserving queueing discipline for enabling this service in Linux. HTB is quite flexible and versatile, but at large scale (think thousands to million flows) it comes at a cost: 1) cpu cycles predominantly due to stalls caused by shared queus lock contentions 2)extensive memory costs when adding many flows. At 0x14 we have two sessions that are addressing this issue in different ways. Our first talk is from Yosef Kuperman, Rony Efraim and Maxim Mikityanskiy and focuses on offloading HTB to the NIC hardware (Mellanox cnx5). Flow classification takes place in the TC egress clsact to avoid any sorts of (queue) locking. Packets are tagged and the offloaded HTB uses these tags as flow/classids to select the correct queue in the hierarchy. Kuperman et al will go over the challenges they overcame, show performance numbers and solicit feedback. More Info: https://netdevconf.info/0x14/session.html?talk-hierarchical-QoS-hardware-of… Our second talk is from the Google folks Stanislav Fomichev, Eric Dumazet, Willem de Bruijn, Vlad Dumitrescu, Bill Sommerfeld and Peter Oskolkov. Google has for many years utilized HTB and consequently faced scaling challenges. With the recent introduction of Early Departure Time model (See Van Jacobson's keynote on EDT in netdev 0x12), an opportunity has opened up to achieve the same packet service in a more efficient way. In this talk, Stan et al describe how they moved away from HTB altogether. The packet service is created using composition of BPF, FQ and EDT. The authors will provide performance numbers, discuss some of the outstanding challenges and solicit feedback from the community. More info: https://www.netdevconf.info/0x14/session.html?talk-replacing-HTB-with-EDT-a… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: New Bronze sponsor, Meter!
by Jamal Hadi Salim 26 Jan '20

26 Jan '20

We are pleased to announce Bronze sponsorship from Meter[meter.com]! Thank you for your support Meter. Meter is the easiest way to get the best Internet and WiFi for offices. Meter takes care of everything, from ISP selection and installation to ongoing support and network management. Meter combines powerful software, custom hardware, and dedicated experts to provide dramatically better Internet speed, security, and reliability. More info: https://netdevconf.info/0x14/news.html?bronze-sponsor-meter-com cheers, jamal

1 0

0x14: nutsnbolts talk, Kernels of Splitting TCP in the Clouds
by Jamal Hadi Salim 26 Jan '20

26 Jan '20

In this talk Markuze Alex et al describe how they improved, by orders of magnitude, client download times of a global overlay network across public clouds. The overlay network known as the Pathway project (operated by VMware Research) interconnects geographical spread of public clouds and their vast compute and networking infrastructure The secret sauce? KTCP, a Kernel module running on a modified Linux Kernel which implements novel TCP splicing. Markuze and co. will discuss why their approach is different relative to the many approaches already out in the wild that implement TCP proxying. They will present numbers against classical approaches which demonstrate that KTCP is able to considerably increase the link utilization by TCP connections and reduce the connection latency close to its theoretical minimum. More info: https://netdevconf.info/0x14/session.html?talk-kernels-of-splitting-TCP-in-… cheers, jamal

1 0

0x14: moonshot, BP4: Byte-code for Programmable Protocol-independent PDU Processing
by Jamal Hadi Salim 26 Jan '20

26 Jan '20

Tom Herbert loves moonshots and three-letter acronyms. First it was XDP and now it is BP4. In this talk, Tom will introduce BP4 - a Domain Specific Language for programmable dataplanes based on unifying the best features of eBPF and P4. The goal of BP4 is “write once, run anywhere, run well!” BP4 is intended to run in _both software and hardware_ execution environments. Central to a BP4 program is a dynamically programmable parser that supports a wide variety of protocols and permits support for new protocols to be added on the fly. The BP4 parser semantics include native support for parsing Variable Length Headers (VLH) that contains TLVs, flag-fields, or variable length arrays. Tom will describe the first PoC for BP4 which leverages the eBPF infrastructure. The PoC implements a flow dissector as a BP4 program by essentially replicating the functionality of the current Linux kernel flow_dissector with extra functionality to handle TLV and flag-fields. The programmable flow dissector will then be used as the basis for a dynamic tc-flower classification (which will allow protocols to be programmed and dynamically added for tc-flower processing). More info: https://netdevconf.info/0x14/session.html?talk-BP4-byte-code-for-programmab… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

0x14: 'Tis A TLS Festival folks!
by Jamal Hadi Salim 24 Jan '20

24 Jan '20

TLS aint cheap on the CPU. The trend on Internet traffic is indicating that the majority of internet traffic is being encrypted with TLS. In other words the most common packets are using TLS! For this reason, we need to pay more attention to TLS performance. At 0x14 we have a small TLS festival. And its all about improving performance. In the first talk, Pawel Szymanski and Manasi Deval that assert the claim that you can achive good performance by letting the CPU do its thing. Use modern CPU instructions like X86 AESNI. They run experiments that compare user-mode TLS, Kernel TLS write and kernel TLS Sendfile to contrast various bottlenecks in each one with regards to encryption and authentication, cost of system calls and the memory bandwidth. They will present their results during the talk. The talk will also provide some insight on which of the three approaches is best suited for different type of application scenarios. More info: https://netdevconf.info/0x14/session.html?talk-TLS-performance-characteriza… And in the second TLS talk, Tariq Toukan, Bar Tuaf and Tal Gilboa discuss offloading of TLS to the NIC. They start by reviewing the life cycle of a HW offloaded kTLS connection and the driver-HW interaction in order to support it. They will then present their experiments where NginX TLS activity is offloaded to the Mellanox ConnectX-6Dx NIC (using mlx5e driver). And finally, they present their experimental results which show significant performance speed-up gained by offloading kTLS operations to the HW. More info: https://netdevconf.info/0x14/session.html?talk-kTLS-HW-offload-implementati… In the third talk, Alexander Krizhanovsky and Ivan Koveshnikov continue their quest(see netdev 0x12 talk) to investigate and improve TLS handshake by moving it into the kernel (currently user space handled). In continuation from 0x12, Alexander and Ivan have been experimenting with new kernel approaches to reduce some perf culprits involved in completing a TLS handshake, namely dynamic memory allocation and big integer initialization. They will present their results which quantify the new approach. The talk will cover many other perf topics related to TLS handshake. More info: https://netdevconf.info/0x14/session.html?talk-performance-study-of-kernel-… Reminder, registration is now open and early bird is still in effect. https://netdevconf.info/0x14/registration.html cheers, jamal

1 0

2024

2023

2022

2021

2020

2019

2018

people