Datacenters are a critical part of the Internet infrastructure as key enablers of cloud computing and web services like search, social networking, and advertising. Quick response to users is essential as a mere hundred milliseconds may lead to substantial revenue losses and drop in customer traffic. However, bursty traffic with high fan-in, oversubscribed links and constrained switch buffers make this a challenging problem. Current approaches to minimize response times range from arbiter based approaches where senders collectively obey global scheduling decisions, to self-adjusting end-host based approaches where senders independently adjust transmission rate based on network congestion. The former incurs greater overhead compared to the latter, which trades off complexityforsuboptimality. Ourworkseeksamiddleground-optimalityofarbiterbased approaches with the simplicity of self-adjusting end-host based approaches. Our thesis is that rather than having a centralized arbiter schedule flows or the senders making independent scheduling decisions, the receiver can coordinate the various flows destined for it to achieve quick response times. We observe that since the receiver has complete knowledge of the flows destined for it, it can coordinate between theses flows without incurring flow switching costs and the overhead of accessing an arbiter. We demonstrate the advantage of receiver driven flow scheduling by addressing two important problems in datacenter networks. First, we address TCP incast, which is the throughputcollapseassociatedwithseveralparallelflowsoverwhelmingtheswitchbuffers. State-of-the-artsolutionsworkwhenuserrequestsareservedbyrack-localmachines. Nowadays, inter-rack communication is also important. We propose RecFlow, which works in both scenarios. A RecFlow receiver spaces ACKs in order to maintain levels of inflight traffic which prevent switch buffer overflows. It calculates its share of the capacity based on the bottleneck information received using OpenFlow. Using packet level simulations, we show that compared to state-of-the-art, RecFlow achieves up to 6x and 1.5x goodput improvement in the inter-rack and the intra-rack scenario respectively. Next, we seek to minimize the number of missed deadlines. Preemptive Earliest DeadlineFirst(EDF)schedulingisconsideredsuitabletoachievethisobjective. However,stateof-the-art approaches that emulate preemptive EDF rely on global flow scheduling which requires customized hardware or a separate control plane. We propose WARDS, a receiver side scheduler which implements preemptive EDF among its flows, through the use of switch priority queues. By using apriori workload information, we probabilistically promote a small number of nearest deadline flows to the top switch queue, thereby reducing the level of multiplexing between nearest deadline flows and those with deadlines further away. Using packet level simulations, we show that WARDS is able to achieve up to 5x performance improvement over state-of-the-art end-host based solutions.
أمطري، لا ترحمي طیفي في عمقِ الظلام أمطري، صبّي علیّ السیل، یا روح الغمام لا تُبالي([2]) أن تعیدیني علی الأرض حطام وأحیلیني([3]) ، إذا شئت، جلیداً أو رُخام
أترکي ریح المساء الممطر الداجي([4]) تجنّ ودعي الأطیار، تحت المطر القاسي، تئنّ أغرقي الأشجار بالماءِ ولا یحزنکِ غصن زمجري([5])، دويّ([6])، فلن أشکو، لن یأتیک لحن
أمطري فوقي، کماشئت، علی وجھي الحزین لا تبالي جسدي الراعش، في کفّ الدجون([7]) أمطري، سیلي علی وجھي، أو غشيّ عیوني بلّلي ما شئت کفيّ وشعري وجبیني
أغرقي، في ظلمۃ اللیل، القبور البالیہ([8]) وألطمي، ما شئتِ أبواب القُصور العالیہ أمطري، في الجبل الناءي([9])، وفوق الھاویۃ([10]) أطفءي النیران، لا تُبقي لحيّ باقیہ
آہ ما أرھبکِ الآن، وقد ساد السکون غیر صوتِ الرّیح، في الأعماق([11]) تدوي في جنون لم تزل تھمي([12])، من الأمطار، في الأرض، عیون لم یَزٖل، قلبي حزیناً، تحت أمواج الدُجون
أیّھا الأمطارُ، قد ناداکِ قلبي البشريُّ ذلک المفرق في الأشواق، ذاک الشاعريّ إغسلیہ، أم تری الحزنُ حماہ([13]) الأبديّ أبداً ، مثلک یا أمطارُ، دفاقٌ نقيُّ
أبداً یسمعُ، تحت اللیل، وقعَ القطرات ساھماً یحلم بالماضي وألغاز الممات یسأل الأمطار: ما أنتِ؟ وما سرّ الحیاۃ؟ وأنا، فیم وجودي؟ فیم دمعي وشکاتي([14])؟
This research article is based on contribution of sub-continent’s outstanding Islamic personalities and their leading role which they have played in establishing and strengthening linguistically, literarily and cultural links between Arabs and non-Arabs Various Arabic cultured institutions of higher learning under the personal guidance and scholarly interest Sultans setups which produced a good number of writers, Islamic thinkers, commentators of the holy Quran, scholars of hadith and understanding of language and literature. Moreover, their nobal work can be composed to any great arab scholar. The work, personalities and their extra ordinary Arabic books including literature in sub-continent is key part of this research. These personalities are Ameer Ali, Mohammad Aizaz Ali, Allama Syed Abu-Alhasan Ali Al-Nadvi, Shah Waliullah Dehlvi, Mahmmod Bin Muhammad Al Janfori, Shaikh Nizamuddin Lakhnavi, Al-Hindi Saffiduddin and Hazarat Shah Ismail Shaeed Brailvi.
A series of novel and biologically potent organometallic complexes using Nheterocyclic carbenes (NHCs), cephalosporin derivatives, quinolilone derivatives, vitamins and antiviral molecules as ligands has been synthesized. The geometry of the synthesized ligands and their metal adducts are done through state of the art spectral tools like NMR (1H, 11B, 19F) UV/Visible and FT-IR. It is confirmed through these spectral studies that in the NHCs the metal is bonded through the active carbine side while in other classes metal is bonded through either oxygen or through nitrogen in some cases. After synthesizing the ligand and the metals molecules are subjected to a variety of biological tests like, antibacterial, antifungal, antioxidant, Positron emission topography and ADMET studies in order to evaluate the bio-potential of the synthesized molecules. Some of the selected compounds are screened with various microorganisms like Gram positive bacteria, Gram negative bacteria and with some fungi. The results obtained are quite impressive, it can be shown that ligands in its free state possess less activity while it is clear from the results that their activity shifts to greater extent while treated with various metals. This clearly shows that metals are responsible for the bioactivity. Further, the molecular docking study was also carried out for Tin(IV) Schiff bases complex in order to correlate the biological experimental results. As in the parent study the Tin(IV) Schiff base complexes derived from piperenol and Entecavir exhibit excellent biological results which were further confirmed through molecular docking study. For some of the molecules ADMET study was also carried out in order to check/correlate the experimental data. ADMET study also confirmed the experimental results. It can be concluded from the present study that the organometallic complexes/metal molecules can serve as potent agents in curing many diseases and may prove their role as future metal base drugs.