Abstract: Embodiments of a system that determines a condition associated with an integrated circuit disposed on a circuit board are described. During operation, the system receives electromagnetic-interference (EMI) signals from one or more antennas while the integrated circuit is operating, where the one or more antennas are disposed on the circuit board. Then, the system analyzes the received EMI signals to determine the condition.

Abstract: The disclosed embodiments provide a system that analyzes telemetry data from a computer system. During operation, the system obtains the telemetry data as a set of telemetric signals using a set of sensors in the computer system. Next, the system uses a regularization technique to calculate a temperature derivative with respect to time for a component in the computer system from the telemetric signals. Finally, the system controls a subsequent value of the temperature derivative with respect to time by modulating a fan speed in the computer system based on the calculated temperature derivative with respect to time and the telemetric signals.

Abstract: The disclosed embodiments provide a system that prevents oscillatory load behavior for a multi-node distributed system. During operation, the system uses a load-balancing policy to distribute requests to nodes of the distributed system. The system determines operational characteristics for the nodes as they process a set of requests, and then uses these operational characteristics to compute machine queuing models that describe the machine state of each node. The system then uses this machine state for the nodes to determine whether the load-balancing policy and the distributed system are susceptible to oscillatory load behavior.

Abstract: Some embodiments of the present invention provide a system that stores telemetry data from a computer system. The system includes a first buffer, a second buffer, and a third buffer. During operation, the system periodically obtains the telemetry data from the computer system and stores the telemetry data in the first buffer, second buffer, and third buffer. The system also compresses the telemetry data in the first and second buffers. To compress the data, the system creates a first set of summary statistics from the telemetry data in the first buffer and the second buffer and stores the first set of summary statistics in the first buffer, which becomes a historical data buffer.

Abstract: A method for performing server monitoring via condition tracking and state identification of server components. In one embodiment, the method includes continuously monitoring a server, the server having a plurality of components, determining whether a component of the plurality of components has entered a maintenance state, and triggering a maintenance action for the component if it has entered the maintenance state.

Abstract: Some embodiments of the present invention provide a system that schedules read operations for disk drives in a set of disk drives. During operation, the system monitors a write rate for write operations to a given disk drive in the set of disk drives, wherein vibrations generated by the read operations directed to disk drives in the set of disk drives are transmitted to the given disk drive. Then, the read operations for disk drives in the set of disk drives are scheduled based on the write rate for the given disk drive, thereby limiting interference between the write operations and the vibrations generated by the read operations.

Abstract: Some embodiments of the present invention provide a system that analyzes data from a computer system. During operation, the system obtains the sensor data from a component in the computer system using a set of sensors. Next, the system transmits the sensor data to a microcontroller unit (MCU) coupled to the sensors and stores the sensor data in internal memory of the MCU. Finally, the system assesses the integrity of the component by analyzing the sensor data using a pattern-recognition apparatus in the MCU.

Abstract: A system for characterizing vibration of a rack structure having at least one hard disk drive disposed therein and a vibration exciter operatively associated with the rack structure includes one or more computers. The one or more computers are configured to command the vibration exciter to provide vibration input to the rack structure and to command a plurality of reads from the at least one hard disk drive such that, for each of the plurality of reads, data stored on the at least one hard disk drive is retrieved from the at least one hard disk drive. The one or more computers are also configured to obtain read rate information related to the plurality of reads and to identify at least one resonant frequency of the rack structure based on the read rate information.

Abstract: One embodiment of the present invention provides a system that characterizes a computer system parameter by analyzing a target electromagnetic signal radiating from the computer system. First, the system monitors the target electromagnetic signal using a first directional antenna located outside of the computer system, wherein the first directional antenna is directed at a location inside the computer system. The system also monitors the target electromagnetic signal using a second directional antenna located outside of the computer system, wherein a receiving axis of the second antenna is oriented non-parallel to a receiving axis of the first antenna, and wherein the second directional antenna is directed at the location inside the computer system. Next, the system characterizes the computer system parameter based on the target electromagnetic signal received from the first antenna and the target electromagnetic signal received from the second antenna.

Abstract: A system for determining vibration of at least one hard disk drive includes one or more computers configured to command a plurality of reads from the at least one hard disk drive such that, for each of the plurality of reads, data stored on the at least one hard disk drive is retrieved directly from the at least one hard disk drive. The one or more computers are also configured to obtain read rate information related to the plurality of reads and to determine a vibration level experienced by the at least one hard disk drive based on the read rate information.

Abstract: Some embodiments provide a system that analyzes telemetry data from a monitored system. During operation, the system obtains the telemetry data as a set of telemetric signals from the monitored system and groups the telemetry data into one or more clusters of correlated telemetric signals from the telemetric signals. Next, the system increases a bandwidth associated with monitoring the telemetric signals. To increase the bandwidth, the system omits one or more of the correlated telemetric signals from each of the clusters during sampling of the telemetric signals and estimates the omitted correlated telemetric signals by applying a nonlinear, nonparametric regression technique to the sampled telemetric signals.

Abstract: Some embodiments of the present invention provide a system that schedules read operations for disk drives in a set of disk drives. During operation, the system monitors a write rate for write operations to a given disk drive in the set of disk drives, wherein vibrations generated by the read operations directed to disk drives in the set of disk drives are transmitted to the given disk drive. Then, the read operations for disk drives in the set of disk drives are scheduled based on the write rate for the given disk drive, thereby limiting interference between the write operations and the vibrations generated by the read operations.

Abstract: Some embodiments of the present invention provide a system that characterizes the performance of a disk drive at frequencies in a set of frequencies in a frequency range. First, the disk drive is vibrated at each frequency in the set of frequencies, one frequency at a time. During this process, a disk drive performance metric is monitored. Next, the performance of the disk drive is characterized by determining the parameter related to acceleration due to the vibrations for each frequency at which a disk drive performance metric degrades by a predetermined amount from a baseline.

Abstract: A system for characterizing vibration of a rack structure having at least one hard disk drive disposed therein and a vibration exciter operatively associated with the rack structure includes one or more computers. The one or more computers are configured to command the vibration exciter to provide vibration input to the rack structure and to command a plurality of reads from the at least one hard disk drive such that, for each of the plurality of reads, data stored on the at least one hard disk drive is retrieved from the at least one hard disk drive. The one or more computers are also configured to obtain read rate information related to the plurality of reads and to identify at least one resonant frequency of the rack structure based on the read rate information.

Abstract: One embodiment provides a system that mitigates vibrations caused by cooling fans in a computer system. More specifically, the system includes a cooling fan mechanically coupled to the chassis of the computer system, wherein vibrations generated by the cooling fan are coupled to the chassis. The system also includes an actuation mechanism that creates a relative displacement between the cooling fan and the chassis when a control signal is applied to the actuation mechanism. The system additionally includes a detection mechanism which detects the relative displacement and generates a feedback signal which represents the relative displacement. The system further includes a control signal generation mechanism which converts the feedback signal into the control signal, which is subsequently applied to the actuation mechanism. When the control signal is applied to the actuation mechanism, the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from the chassis.

Abstract: Some embodiments of the present invention provide a system that attenuates noise from a fan exhaust of a computer system. During operation, the system monitors the noise from the fan exhaust and calculates a frequency spectrum of the noise from the monitored noise. Next, the system generates an antiphase spectrum from the frequency spectrum and generates a flow of air which exhibits a property of the antiphase spectrum. Finally, the system directs the flow of air into the fan exhaust so that the noise is attenuated by a reduction of turbulence in the fan exhaust by the flow of air.

Abstract: Embodiments of a computer system that includes a vibration-cancelling mode, and a related method and computer-program product (e.g., software) for use with the computer system, are described. During operation, a processor monitors operations in the computer system, and may select either the vibration-cancelling mode or an inactive mode based on the monitored operations. For example, the processor may select the vibration-cancelling mode when there are input/output-(I/O) intensive workloads to an array of one or more hard disk drives (HDDs) in the computer system. In this way, the processor may reduce the energy consumption associated with vibration-induced retries to the HDDs (and reduced I/O throughput) without increasing the energy consumption associated with active vibration damping at other times, such as when the computer system is idle or during processor-intensive workloads.

Abstract: Some embodiments of the present invention provide a system that controls a power utilization of a computer system by adjusting a cooling fan speed. During operation, a relationship between information related to the cooling fan speed and the power utilization is determined. Then, the cooling fan speed is adjusted based on the determined relationship to control the power utilization of the computer system.

Abstract: One embodiment of the present invention provides a system that generates vibration-resistance signatures for hard disk drives (HDDs). In this system, a set of HDDs is mechanically affixed to a disk enclosure. The system additionally includes a vibration generator which is mechanically coupled to the disk enclosure and can apply a translational vibration profile to the disk enclosure. The system further includes a coupling mechanism between the set of HDDs and the disk enclosure which translates the translational vibration profile into both translational and rotational vibrations for the set of HDDs in multiple dimensions. The system additionally includes a monitoring mechanism which monitors an HDD performance metric from the set of HDDs while the HDDs are subject to the translational and rotational vibrations. The system also includes a signature-generation mechanism which uses the monitored HDD performance metric to generate vibration-resistance signatures for the set of HDDs.

Abstract: Some embodiments of the present invention provide a system that controls a device that characterizes the health of a computer system power supply. During operation, a signature for the power supply is generated based on measurements of a set of performance parameters for the power supply. Then, the health of the power supply is characterized based on a comparison between the signature for the power supply and signatures for one or more other power supplies.