BER Illusion Methodology: A Novel, Open Sourced and Scalable Approach to Troubleshooting High Radix Photonics Interconnects in a Modern Hyperscale Datacenter

2021 ◽  
Author(s):  
Shreyas Rao ◽  
Abhijit Chakravarty ◽  
Dharmesh Jani
Keyword(s):  
Optical Interconnects ◽  
First Generation ◽  
Failure Detection ◽  
Previous Method ◽  
Three Dimensions ◽  
Link Failure ◽  
Transmitter Power ◽  
Root Cause ◽  
User Request ◽  
Universal Applicability

Abstract Facebook Datacenter consists of a large number of servers that run diverse Facebook services aggregated to serve any given user request. To allow this aggregation, servers have to interact with each other via different traffic flows which are managed by networking fabric. The underlying connection powering this fabric consists of a large number of pluggable optical interconnects and On Board Optical (OBO) modules carrying production data. This connectivity at scale requires fast and reliable detection of the link failures to ensure resolution. In the first generation of the deployments, detection of the link failure was sequential and a slow process. The troubleshoot process was equally tedious as the available tools required characterizing one optical transceiver at a time. Further, the failure analysis also presented a majority of resolution with no failed optics as a root cause resulting in high No Trouble Found (NTF) rate. In this paper we introduce a novel link failure detection and resolution method that improves on the previous method across three dimensions: faster resolution, reliable troubleshooting and scalable implementation. We introduce BER Illusion Methodology (BIM) that is a highly scalable and resource efficient solution that significantly reduces the time taken to troubleshoot pluggable optical interconnects. This is also scalable to next-gen OBO modules at Facebook datacenters aiming to lower the NTF rate and optimally utilizing the available resources. BIM, which is based on Open Compute Platform (OCP) network switches, can be used to troubleshoot 128 QSFP28, 64 QSFP56 or 32 OBO modules simultaneously in under 30 minutes. The tool is easy to implement and capable of also reporting diagnostics on the transceiver such as Transmitter Power, Transmitter Bias Current, Receiver Power, Case Temperature, Bit Error Rate result per channel, Vendor information and Manufacturing part number. This additional test data report along with true failure indication helps optic suppliers gain confidence and build customer credibility. The open-source nature and the universal applicability of this tool offers possibility for other users to adopt and further customize it for their networking needs.

scholarly journals Link Failure Detection and Classification in Wireless Sensor Networks using Classification Method

2019 ◽  
Vol 8 (12) ◽  
pp. 1132-1135
Keyword(s):  
System Performance ◽  
Detection Rate ◽  
Sensor Node ◽  
Weak Link ◽  
Failure Detection ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Link Failure ◽  
Packet Delivery

This paper develops a method to detect the failures of wireless links between one sensor nodes to another sensor node in WSN environment. Every node in WSN has certain properties which may vary time to time based on its ability to transfer or receive the packets on it. This property or features are obtained from every node and they are classified using Neural Networks (NN) classifier with predetermined feature set which are belonging to both weak link and good link between nodes in wireless networks. The proposed system performance is analyzed by computing Packet Delivery Ratio (PDR), Link Failure Detection Rate (LFDR) and latency report.

Integration and volunteering: the case of first-generation immigrants to Canada

2021 ◽  
Author(s):  
A. Stefanie Ruiz ◽  
Lili Wang ◽  
Femida Handy
Keyword(s):  
National Survey ◽  
First Generation ◽  
Immigrant Integration ◽  
Three Dimensions ◽  
First Generation Immigrants ◽  
Different Dimensions ◽  
Using Data ◽  
The Relationship

This study investigates the association between the integration of first-generation immigrants and their volunteering. Using data from a Canadian national survey, we examine three dimensions of immigrant integration: professional, psychosocial and political. General volunteering is not significantly related to integration; however, there exists a relationship between the different dimensions of integration and where immigrants choose to volunteer. Thus, the relationship between the type and degree of immigrant integration and volunteering is nuanced; it matters where volunteering occurs.

Failures in Soldering

2021 ◽  
pp. 326-337
Author(s):  
Qiming Zhang ◽  
Babak Kondori ◽  
Xing Qiu ◽  
Jeffry C.C. Lo ◽  
S.W. Ricky Lee
Keyword(s):  
Solder Joint ◽  
Failure Analysis ◽  
Manufacturing Process ◽  
Failure Modes ◽  
Solder Joints ◽  
Failure Detection ◽  
Cause Analysis ◽  
Root Cause ◽  
Integration Density ◽  
Root Cause Failure Analysis

Abstract Due to the recent requirement of higher integration density, solder joints are getting smaller in electronic product assemblies, which makes the joints more vulnerable to failure. Thus, the root-cause failure analysis for the solder joints becomes important to prevent failure at the assembly level. This article covers the properties of solder alloys and the corresponding intermetallic compounds. It includes the dominant failure modes introduced during the solder joint manufacturing process and in field-use applications. The corresponding failure mechanism and root-cause analysis are also presented. The article introduces several frequently used methods for solder joint failure detection, prevention, and isolation (identification for the failed location).

scholarly journals Validation of the brief scale for the evaluation of acculturation stress in migrant population (EBEA)

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Alfonso Urzúa ◽  
Diego Henríquez ◽  
Alejandra Caqueo-Urízar ◽  
Vanessa Smith-Castro
Keyword(s):  
Mental Health ◽  
Psychological Health ◽  
First Generation ◽  
Well Being ◽  
Three Dimensions ◽  
Acculturation Stress ◽  
Migrant Population ◽  
Physical And Mental Health ◽  
Culturally Adapted ◽  
Nomological Validity

Abstract Background Acculturation stress is associated with poorer physical and mental health and a lower level of psychological well-being. The causes of acculturation stress are diverse, but most are similar in the migrant population. Despite the importance of evaluating this variable, few studies have reported culturally adapted and validated instruments for specific populations. Based on this, the aim of this study was to evaluate the psychometric properties of a short scale for the evaluation of acculturation stress (EBEA). Methods Two studies were conducted, involving 1725 first-generation Colombian and Peruvian migrants living in Chile, between the ages of 18 and 60 years. In addition to the EBEA and as evidence of validity, the Beck Anxiety Scale and the WHOQOL-BREF psychological health domain were applied. A confirmatory factor analysis was carried out, and the reliability and nomological validity were evaluated. Results The results in both studies indicated that the scale presents a factorial structure of three dimensions: (a) the stress derived from the preparation and departure from the country of origin, (b) the stress produced by socioeconomic concerns in the host country, and (c) the tensions typical of adaptation to sociocultural changes or Chilean society. The reliability coefficients and the analysis of their nomological validity were very good. Conclusions The EBEA is a measure that offers quick, useful screening for researchers who need a short measure for research among migrants. This tool contributes to the work of education, prevention, and intervention in the field of general health and migrants’ mental health.

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