Abstract
The LHCb Data Acquisition (DAQ) will be upgraded in 2020 to a trigger-free readout. In order to achieve this goal we will need to connect around 500 nodes with a total network capacity of 32 Tb/s. To get such an high network capacity we are testing zero-copy technology in order to maximize the theoretical link throughput without adding excessive CPU and memory bandwidth overhead, leaving free resources for data processing resulting in less power, space and money used for the same result. We develop a modular test application which can be used with different transport layers. For the zero-copy implementation we choose the OFED IBVerbs API because it can provide low level access and high throughput. We present throughput and CPU usage measurements of 40 GbE solutions using Remote Direct Memory Access (RDMA), for several network configurations to test the scalability of the system.
Highlights
The LHCb [1] experiment is one of the four big experiments placed in the Large Hadron Collider (LHC), situated in Geneva Switzerland
To handle the big amounts of data produced by the detector the Data Acquisition System (DAQ) selects interesting events according to the underling physics in a multi-stage process usually called trigger
This transport layer is integrated in the Data Acquisition Protocol Independent Evaluator [2] (DAQPIPE) emulation software, which emulates an DAQ network traffic and makes possible to measure the performances of different network technologies
Summary
This content has been downloaded from IOPscience. Please scroll down to see the full text. Ser. 608 012029 (http://iopscience.iop.org/1742-6596/608/1/012029) View the table of contents for this issue, or go to the journal homepage for more. Download details: IP Address: 131.169.4.70 This content was downloaded on 26/05/2015 at 20:53 Please note that terms and conditions apply
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