TimeTrader: Exploiting Latency Tail to Save Datacenter Energy for On-line Data-Intensive Applications

Datacenters running on-line, data-intensive applications (OLDIs) consume significant amounts of energy. However, reducing their energy is challenging due to their tight response time requirements. A key aspect of OLDIs is that each user query goes to all or many of the nodes in the cluster, so that the overall time budget is dictated by the tail of the replies' latency distribution; replies see latency variations both in the network and compute. Previous work proposes to achieve load-proportional energy by slowing down the computation at lower datacenter loads based directly on response times (i.e., at lower loads, the proposal exploits the average slack in the time budget provisioned for the peak load). In contrast, we propose TimeTrader to reduce energy by exploiting the latency slack in the sub- critical replies which arrive before the deadline (e.g., 80% of replies are 3-4x faster than the tail). This slack is present at all loads and subsumes the previous work's load-related slack. While the previous work shifts the leaves' response time distribution to consume the slack at lower loads, TimeTrader reshapes the distribution at all loads by slowing down individual sub-critical nodes without increasing missed deadlines. TimeTrader exploits slack in both the network and compute budgets. Further, TimeTrader leverages Earliest Deadline First scheduling to largely decouple critical requests from the queuing delays of sub- critical requests which can then be slowed down without hurting critical requests. A combination of real-system measurements and at-scale simulations shows that without adding to missed deadlines, TimeTrader saves 15-19% and 41-49% energy at 90% and 30% loading, respectively, in a datacenter with 512 nodes, whereas previous work saves 0% and 31-37%.Comment: 13 page

Evaluation of antipyretic activity of alcoholic extract of Murraya koenigii leaves in rabbits

Background: The present study was carried out to evaluate the antipyretic activity of alcoholic extract of Murraya koenigii leaves in rabbits by using PGE1 induced hyperpyrexia method. We found that not much work has been done on the antipyretic effect of this plant.Methods: Laboratory breed New Zealand strains of rabbits of either sex weighing 1000-1500 gm were used in the study. The animals were divided into five groups (n=6). The rabbits of all the groups were made febrile by injecting misoprostol (PGE1) subcutaneously in the dose of 100 mcg/kg.  For group 1 and 2, normal saline 2ml/kg as control and aspirin 28mg/kg as standard were given respectively. Alcoholic extract of Murraya koenigii leaves in the doses of 200, 400 and 800mg/kg were administered in remaining three groups respectively. Rectal temperatures were recorded with help of digital thermometer for every 30 min after drug treatment.Results: Alcoholic extract of Murraya koenigii produced highly significant (p<0.001) antipyretic effect in 400 and 800 mg/kg doses. But onset of action was fast with 800mg/kg dose.Conclusions: This study concludes that Alcoholic extract of Murraya koenigii has fast onset of action and also exhibited sustained anti pyretic action in New Zealand rabbits

Exposure to stress minimizes the zone of antimicrobial action: a phenotypic demonstration with six Acinetobacter baumannii strains

Aim: To phenotypically study the role of domestic environmental stress in the emergence of antimicrobial resistance in Acinetobacter baumannii. Materials and Methods: Six strains of A. baumannii were initially subjected to AST and then were exposed to various stresses (temperature, pH and random combinations). Stressed cells were subcultured and then subjected for AST. The ZOIs before and after exposure to stress were compared. Statistical analysis was done using Student t-test at p &lt; 0.10. Results: Exposure to stresses and combination of stresses resulted in substantial reduction in the ZOIs. Stress hardening was associated with further reduction in ZOIs. Conclusion: Exposure to domestic environmental stress imparted a significant and substantial reduction in the susceptibility of A. baumannii strains to antibiotics. DOI: http://dx.doi.org/10.5281/zenodo.118415

A Model of Practice Related Shifts in the Locus of Brain Activity During Verbal Response Selection Tasks

Recent Positron Emission Tomography (PET) and other studies have produced detailed information about the areas of the brain involved in word association tasks, their functional roles in learning word associations, and the changes in activity in these areas during learning. We present a dynamic neurond model that replicates observed human cognitive behavior in learning word as?sociations while satisfying salient neuroanatomical and neuropsychological constraints. The model captures the observed dynamics of cortico-thalamo-basal ganglionic loops

SafeBet: Secure, Simple, and Fast Speculative Execution

Spectre attacks exploit microprocessor speculative execution to read and transmit forbidden data outside the attacker's trust domain and sandbox. Recent hardware schemes allow potentially-unsafe speculative accesses but prevent the secret's transmission by delaying most access-dependent instructions even in the predominantly-common, no-attack case, which incurs performance loss and hardware complexity. Instead, we propose SafeBet which allows only, and does not delay most, safe accesses, achieving both security and high performance. SafeBet is based on the key observation that speculatively accessing a destination location is safe if the location's access by the same static trust domain has been committed previously; and potentially unsafe, otherwise. We extend this observation to handle inter trust-domain code and data interactions. SafeBet employs the Speculative Memory Access Control Table (SMACT) to track non-speculative trust domain code region-destination pairs. Disallowed accesses wait until reaching commit to trigger well-known replay, with virtually no change to the pipeline. Software simulations using SpecCPU benchmarks show that SafeBet uses an 8.3-KB SMACT per core to perform within 6% on average (63% at worst) of the unsafe baseline behind which NDA-restrictive, a previous scheme of security and hardware complexity comparable to SafeBet's, lags by 83% on average

Evaluation of new insecticide molecules for their effectiveness in the management of sugarcane early shoot borer, Chilo infuscatellus (Snellen)

An experiment was conducted at Zonal Agricultural Research Station, V.C farm, Mandya (Karnataka), India during 2015, to assess the chemical control of sugarcane early shoot borer (Chilo infuscatellus). Nine insecticides namely, Fipronil 0.3G, Chlorantraniliprole 0.4G, Chlorantraniliprole 18.5 SC, Spinosad 45SC, Flubendiamide 39.35SC, Cartap hydrochloride 4G, Phorate 10G, Carbofuran 3G, Chlorpyriphos 20EC, and compared with untreated (Check plot)using randomized block design with three replications. Significant differences were noticed among the treatments. Chlorantraniliprole 0.4G recorded lowest cumulative incidence (2.79 %) and highest per cent reduction over the control (85.78 %) which was followed by Cartap hydrochloride 4G (5.37% and 72.65%), Chlorantraniliprole 18.5 SC (5.95% and 75.62%), Flubendiamide 39.35SC (6.64% and 66.19%) and Fipronil 0.3G (6.83% and 65.22%) were found significantly superior in reducing the cumulative incidence of C. infuscatellus.In Co 86032 Cartap hydrochloride 4G was found to be the best insecticide in getting a highest cost benefit ratio (1:12.39). Other insecticides such as Fipronil 0.3G (1:8.84), Chlorantraniliprole 0.4G (1:6.96), Flubendiamide 39.35SC (1:5.42) and Spinosad 45SC (1:4.16) have also recorded better cost benefit ratio. Since Cartap hydrochloride 4G does not have crop label so we can recommend Fipronil 0.3G or Chlorantraniliprole 0.4G for the management of sugarcane early shoot borer

Smash Guard: A Hardware Solution to Prevent Security Attacks on the Function Return Address

A buffer overflow attack is perhaps the most common attack used to compromise the security of a host. A buffer overflow can be used to change the function return address and redirect execution to execute the attacker\u27s code. We present a hardware-based solution, called SmashGuard, to protecting the return addresses stored on the program stack. SmashGuard protects against all known forms of attack on the function return address pointer. With each function call instruction a new return address is pushed onto an extra hardware stack. A return instruction compares its return address to the address from the top of the hardware stack. If a mismatch is detected, then an exception is raised. Because the stack operations and checks are done in hardware, and in parallel with the usual execution of call and return instructions, our bestperforming implementation scheme has virtually no performance overhead. While previous software-based approaches\u27 average performance degradation for the SPEC2000 benchmarks is only 2.8%, their worst-case degradation is up to 8.3%. Apart from the lack of robustness in performance, the software approaches\u27 key disadvantages are less security coverage and the need for recompilation of applications. SmashGuard, on the other hand, is secure and does not require recompilation, though the OS needs to be modified to save/restore the hardware stack at context switches, and when function call nesting exceeds the hardware stack depth

Achieving Causal Consistency under Partial Replication for Geo-distributed Cloud Storage

Causal consistency has emerged as an attractive middle-ground to architecting cloud storage systems, as it allows for high availability and low latency, while supporting stronger-than-eventual-consistency semantics. However, causally-consistent cloud storage systems have seen limited deployment in practice. A key factor is these systems employ full replication of all the data in all the data centers (DCs), incurring high cost. A simple extension of current causal systems to support partial replication by clustering DCs into rings incurs availability and latency problems. We propose Karma, the first system to enable causal consistency for partitioned data stores while achieving the cost advantages of partial replication without the availability and latency problems of the simple extension. Our evaluation with 64 servers emulating 8 geo-distributed DCs shows that Karma (i) incurs much lower cost than a fully-replicated causal store (obviously due to the lower replication factor); and (ii) offers higher availability and better performance than the above partial-replication extension at similar costs