Data center aisle obstruction detection

A system for detecting air flow obstruction in a data center is described. The system is configured to detect that an air outlet of the data center has been obstructed. A time period during which the air outlet is obstructed is determined. An alarm is activated when the air outlet has been obstructed for a predetermined time period.

BACKGROUND

A data center is a facility that houses computer systems and various networking, storage, and other related components. Many organizations and businesses utilize data center resources to provide computing and information services to support their day-to-day operations. Data centers may provide computing services to businesses and individuals as a remote computing service or to provide “software as a service” (e.g., cloud computing). The services provided by data centers are typically implemented with large quantities of computing equipment at the data center. It is important to efficiently perform maintenance activities for the computing equipment.

DETAILED DESCRIPTION

A data center provides computing resources to users via user computers over a communications network such as the Internet. The computing resources can include various types of resources, such as data processing resources, data storage resources, data communication resources, and the like. Data centers typically serve many hundreds or thousands of customers, and can house thousands of servers and other computing equipment. A data center, for example, may have hundreds or thousands of equipment racks that can house thousands of servers and other computing devices.

Data centers must manage environmental conditions to ensure efficient operation of the computing equipment. Data centers may utilize heating, ventilating, and air conditioning (HVAC) systems to pump pressurized air to maintain proper equipment temperature ranges. Computing equipment in a data center typically takes in cooling air at the front of the equipment and exhausts hot air at the back of the equipment. Data centers typically separate hot and cold airflows to prevent recirculation of hot air exhausted from the computing equipment and to reduce cooling costs. This can be achieved by placing equipment with the front of the equipment racks facing the same direction in a given row, thus causing a consistent airflow direction throughout the equipment racks. Rows of equipment racks may then be oriented so that the fronts of the computing equipment face each other and the backs of the computing equipment face each other in alternating fashion. Such an arrangement results in alternating hot aisles and cold aisles. Referring toFIG. 1, illustrated is an example arrangement of equipment racks110in a data center100. Solid arrows120illustrate cold air being circulated upward from airflow outlets125that receive cooling air from an underfloor source. The dashed arrows130illustrate hot air exhausted from the equipment racks flowing upward. Also illustrated inFIG. 1are a device management cart130and a maintenance cart140. Depending on where the carts are placed by maintenance personnel during maintenance operations, the carts may impede the flow of cold air being circulated upward from airflow outlets125.

The operation of a data center requires the continuous monitoring and maintenance of the data center's equipment to ensure effective utilization of the computing equipment while avoiding or minimizing equipment failures. In a hot aisle/cold aisle arrangement, the data center must monitor the environmental conditions to avoid issues that can arise due to hot air recirculation and mixing, and obstruction or failure of cold air outlets. Such issues can result in hot spots that can allow equipment to operate in non-optimal temperature ranges. The data center may monitor for such conditions by installing temperature sensors to detect such hot spots and to alert data center personnel for troubleshooting and resolution of the issue.

One problem that can arise is that data center personnel may inadvertently place work carts over the cold air outlets. The cold air outlets may include floor diffusers or other cold air distribution mechanisms. Data center personnel may also obstruct the cold air outlets by standing over the outlets. Such obstructions can temporarily block the flow of cooling air in a particular area of a cold aisle, causing local hot spots or preventing cooling air from reaching the temperature sensors. This can trigger alarms that require investigation by maintenance personnel to determine the source of the problem. The expenditure of resources to troubleshoot and resolve such avoidable events can be an unnecessary drain on a data center's resources and increase the cost of maintaining a data center. Furthermore, troubleshooting of such events may result in unnecessary shutdown of equipment, which may ultimately affect the availability of computing equipment and thus the ability of the data center to provide continuous access to resources by the data center's customers.

Described in this disclosure are systems and methods for detecting obstructions of cold aisle air flow in a data center and generating notifications of the obstructions. In one embodiment, a detection and notification system can be installed in a data center to provide local and/or remote notifications in the event that a cold air outlet is blocked for a predetermined period of time. By providing such a notification, potential obstruction events can be avoided or resolved before a temperature alarm is registered and a maintenance event is triggered. One advantage of providing notifications of potential obstructions is that the notifications can be used to change the habits and actions of data center maintenance personnel so as to avoid behaviors that are likely to result in the unintentional blocking of cooling air to the temperature sensors on the equipment racks.

In one embodiment, energy emitters may be used to detect the presence of a person or object that may obstruct the cold air outlets. For example, one or more laser detection devices may be used to detect a potential obstruction of a cold air outlet. The laser detection devices may be placed so as to detect objects or personnel in a path between the cold air outlets and the temperature sensors. When a laser detection device is located in the proximity of a cold air outlet and detects a cart or a person along a line-of-sight of the laser detection device, a timer may be used to determine if the cart or a person remains in place long enough to cause a cooling air blockage event. The timer may, for example, determine if the cart or a person remains in place for greater than a predetermined threshold time period (e.g., 40 seconds). If the line-of-sight of the laser detection device remains blocked for the predetermined threshold time period, then it may be assumed that the air flow outlet has been obstructed. The laser detection device may provide a signal to an alarm which may activate appropriate notification actions, such as generating an audio alarm and illuminating a warning light, as configured by the data center operators. The sound level of the alarm may be configured to generate a sufficient sound level for personnel in the general vicinity of the cold aisle to hear above the ambient noise of the equipment. Additionally, a number of warning lights may be installed at locations throughout the cold aisle to increase the likelihood that personnel will view the lights when activated. The alarm may be deactivated when the obstruction has been removed and is no longer sensed by the laser detection device.

Referring again toFIG. 1, illustrated is data center100that includes four computing equipment racks110, forming two cold air aisles160. The computing equipment racks110may generally be situated throughout the data center100. Each of the computing equipment racks110may house a number of computing, storage, and other devices. The data center100may house hundreds or thousands of such computing equipment racks110in various configurations, and the computing equipment racks110may be further segregated into rooms, bays, or other such structures. The warning lights may be installed through the data center100, or may be localized to specific cold air aisles.

While the present disclosure describes examples in terms of hot and cold aisles in a data center, it should be understood that the disclosed principles may be applied to other computing environments where monitoring of environmental conditions is desired.

Referring toFIG. 2, illustrated is an example system200for detecting air flow obstruction in a data center. In an embodiment, system200may be an integrated system that can perform the operations of sensing obstruction of a cold air outlet of the data center and activate a signal when the obstruction is sensed. The system200may be configured to determine a time period during which the obstruction is sensed, and generate an indication in response to the obstruction being sensed for a predetermined time period. The system200may further be configured to activate an alarm in response to receiving the indication from the timer. In some embodiments, the system200may further be capable of communicating with networks and systems of the data center to send and receive information for alarm events, and providing notifications that obstructions are sensed or removed.

Referring toFIG. 2, illustrated are equipment racks250and260that form a cold air aisle270. A temperature sensor205may be installed on equipment rack250and may be configured to sense the ambient temperature. In this example, a number of laser emitters210are installed to generate laser lines-of-sight220across the cold aisle270to a number of reflectors215that are located across the cold aisle270. Each emitter210also comprises a detector to determine whether the laser light is reflected back to the emitter210by the reflector215. The laser emitters210are communicatively coupled to alarm225. When an obstruction is detected by one of the laser emitters210, the laser emitters210may start a timer (not shown) to determine if the obstruction remains in place for a predetermined time period. If the laser emitters210determine that the obstruction has remained in place for the predetermined time period, a signal may be sent to the alarm225to activate an audio or visual alarm.

The laser emitters210may also be communicatively coupled to other systems of the data center. For example, the laser emitters210may include a wired or wireless network interface component that is configured to communicate with available networks using technologies, such as Wifi or BLUETOOTH, and exchange information with other systems of the data center. The laser emitters210may send information regarding the location and time of any cooling airflow obstruction events.

For example, the laser emitters210may communicate with a data center management system (not shown) and access a maintenance database or data logs. Each laser emitters210may be uniquely identified at the data center to allow for identification and management of the laser emitters210.

As shown in the example embodiment ofFIG. 2, a laser emitter, detector, and timer may be housed in a single device with the standalone reflector located across the cold aisle. The laser detector may be an optical detector and may include circuitry to detect the interruption of the laser light emitted by the emitter and begin a countdown timer. For example, a countdown timer may comprise a charging capacitor and potentiometer. The countdown timer may include an adjustable time threshold that implements the predetermined time period after which an alarm is generated. In one embodiment, the countdown timer may include a relay that is configured to be energized when the adjustable time threshold is reached, causing a signal to be send to the alarm.

As shown in this embodiment, multiple laser emitters may be communicatively coupled to a single alarm device. The laser emitters may be installed, for example, to detect obstructions for all cold air outlets of one cold aisle, allowing for a single alarm device to be used for each cold aisle.

In some embodiments, the laser emitter, detector, and timer may be configured to be powered by a readily available power source at the equipment racks and to minimize power consumption. For example, the laser emitter, detector, and timer may be configured to receive a 12 VDC power source.

Referring toFIG. 3, illustrated is another example of a system300for detecting air flow obstruction in a data center. Also illustrated are equipment racks350and360that form a cold air aisle370. A temperature sensor305may be installed on equipment rack350and may be configured to sense the ambient temperature. In this example, a laser emitter310(including an optical detector) is installed to generate a laser line-of-sight across the cold aisle370to reflector315which is located across the cold aisle370at a different elevation as compared to laser emitter310. By locating the laser emitter310and reflector315so that the laser line-of-sight forms a diagonal across the cold aisle370, the larger cross-section of the cold aisle370may be covered for obstruction detection.

In this example, laser emitter310may be communicatively coupled to alarm320using a wireless link380. By using a wireless link, the laser emitter310may be more readily moved to provide area coverage by maintenance personnel. Illustrated is a maintenance cart390that is obstructing the flow of cold air360. When the obstruction is detected by laser emitter310, the laser emitter310may start a timer (not shown) to determine if the obstruction remains in place for a predetermined time period. If the laser emitter310determines that the obstruction has remained in place for the predetermined time period, a wireless signal may be sent to the alarm320to activate an audio or visual alarm.

FIG. 4illustrates an exemplary system for detecting air flow obstruction in a data center. An energy-emitting component410may be provided to emit energy across an area of the data center that is to be monitored for obstructions. When the emitted energy is blocked or interrupted, an obstruction-sensing component420may detect the interruption. The interruption may be interpreted as a potential obstruction of the cold air outlet of the data center. An obstruction signal activation component430may activate a signal when the obstruction is sensed. Based on the signal, a timer initiation component440may activate or initiate a timer. If the time period during which the obstruction is sensed exceeds a predetermined time period, then an alarm activation component450may activate an alarm, indicating that an obstruction to the cooling air outlet has been detected. If the obstruction to the cooling air outlet has been removed, then an alarm termination component460may deactivate the alarm, indicating that the obstruction to the cooling air outlet has been cleared. If the obstruction to the cooling air outlet is removed before the predetermined time period, then stop timer component470may stop and reset the timer to zero, indicating that the obstruction to the cooling air outlet has been cleared. The various components described above may be implemented as hardware or a combination of hardware and software. For example, in some embodiments the energy-emitting component410may be a laser and the obstruction-sensing component420may be a laser light sensor, while the timer initiation component440and the stop timer component470may be implemented as computer-based control system. Furthermore, some or all of the components may be combined into a single device or distributed across multiple devices.

In some embodiments, the energy-emitting component410can comprise a coherent light source installed in a first location of the data center and a photo detector installed in a second location of the data center. The obstruction sensing component420may be configured to detect presence or absence of a threshold amount of coherent light generated by the coherent light source. The obstruction signal activation component430may generate a first signal indicative of the absence of the threshold amount of coherent light generated by the coherence light source. The threshold amount of coherent light may be defined, for example, in terms of the signal-to-noise ratio of detected coherent light energy.

Additionally, the first and second locations may be selected so that an object or person that obstructs the cold air outlet will block, within a predetermined confidence level, coherent light generated by the coherent light source from reaching the photo detector. For example, the first location may be a first side of an aisle of the data center and the second location may be an opposing second side of the aisle of the data center. The predetermined confidence level may be determined based in part on the light source, the expected loss of light generated by the light source, the positions and geometry of the first and second locations, and environmental factors. The confidence level may be determined as a single probability value or a probability distribution function. The confidence value may be empirically derived based on experimentation, or estimated based on a probability model.

In some embodiments, the first and second locations may be selected so as to increase the likelihood that obstructions of various shapes and sizes will be detected by the obstruction sensing component420. For example, a maintenance cart with horizontal shelving may be placed over a cold air outlet and obstruct the flow of cooling air. However, if the first and second locations are at the same height from the floor and form a line that is perpendicular to the cold aisle, then it may be possible for light traveling between the first and second locations to pass through the cart in the empty area between shelves so as not to be detected by the obstruction sensing component420. In one embodiment, the first and second locations may be selected so as to form a non-perpendicular and non-parallel line-of-sight between the first and second locations with respect to the horizontal floor plane of the data center. For example, if the cold aisle forms the X-axis, the horizontal line perpendicular to the cold aisle forms the Y-axis, and the Z-axis is a vertical line that is perpendicular to the floor plane, then the first and second locations may be selected so that the line-of-sight between the two locations are not parallel to any of the three axes. In this way, the likelihood that the obstruction sensing component420will detect the presence of objects of various shapes may be increased.

FIG. 5illustrates an example operational procedure for managing computing resources in a data center. In an embodiment, some or all portions of the operational procedure may be performed by a system for detecting air flow obstruction in a data center, such as system200illustrated inFIG. 2and implemented by the operations illustrated inFIG. 5, which begins with operation500to start the operational procedure. Operation500may be followed by operation502. Operation502illustrates detecting that an air outlet of the data center has been obstructed. In some embodiments, the detection can be performed by a sensing component configured to sense obstruction of the air outlet of the data center. The sensing component can also be configured to activate a signal when the obstruction is sensed.

The sensing component can include an emitter installed in a first location and a detector installed in a second location. The detector may be configured to detect presence or absence of a threshold amount of energy emitted by the emitter, where the absence of the threshold amount of energy may indicate the presence of some obstruction that may block the flow of cooling air. The emitter may emit any energy form such as light, sound, or other energy forms that can travel across a region of the data center. For example, the emitter may include a coherent light source, and the detector may include a photo detector. The photo detector may be configured to detect presence or absence of a threshold amount of coherent light generated by the coherence light source. Although many of the examples described herein use a coherent light source, such as a laser, other light sources can also be used. For example, some embodiments can use an infrared LED as a light source.

In some embodiments, the emitter and detector can both be installed in the same location, and a reflector can be installed in the second location. The reflector can be positioned to reflect energy emitted from the emitter back to the detector in the first location. The installation locations of the emitter and detector, or in the case of the emitter and detector being co-located, the locations of the emitter/detector and reflector, can be selected so as to form a non-perpendicular and non-parallel line-of-sight between the two locations with respect to a horizontal floor plane of the data center. Generally, the line-of-sight may be selected to avoid horizontally traversing the cold aisle so that an obstruction may avoid detection. In some embodiments, the line-of-sight may be selected to maximize the region of three-dimensional space that is traversed through a cold aisle. The line-of-sight may be selected subject to the most likely three-dimensional characteristics of objects and persons that are likely to obstruct an airflow outlet. Furthermore, in some embodiments, multiple emitters/detectors may be installed so as to provide more complete coverage of a cold air aisle.

Operation502may be followed by operation504. Operation504illustrates in response to the detecting, determining a time period during which the air outlet is obstructed. The time period may be determined by a timing component configured to receive the signal from the sensing component and determine a time period during which the obstruction is sensed. The timing component may be configured to generate an indication in response to the obstruction being sensed for a predetermined time period. In some embodiments, a first signal may be sent by the sensing component to the timing component. The first signal may be indicative of the absence of a threshold amount of energy transmitted by an emitter of the sensing component. Responsive to the first signal, the timing component may initiate a timer configured to determine the time period during which the threshold amount of energy is not detected by the sensing component. The timing component may generate a second signal indicating that the threshold amount of energy has not been detected by the sensing component for the predetermined time period. In some embodiments, the sensing component may send a third signal indicating that the obstruction has been removed. In other embodiments, the sensing component may continue to send signals indicating the presence of the obstruction, and stop sending the signals when the obstruction has been removed.

Operation504may be followed by operation506. Operation506illustrates determining if the air outlet is obstructed for a first predetermined time period. If the air outlet is obstructed for the first predetermined time period, then operation506may be followed by operation508, which illustrates activating an alarm when the air outlet has been obstructed for the first predetermined time period. If the air outlet is not obstructed for the first predetermined time period, then operation506may be followed by operation502. The alarm may be activated by an alarm component configured to activate the alarm in response to receiving the indication from the timing component.

Operation508may be followed by operation510, which illustrates determining if the obstruction has been removed. If the obstruction has been removed, then operation510may be followed by operation512, which illustrates deactivating the alarm. In some embodiments, the alarm may be deactivated when the air outlet of the data center is no longer obstructed for a second predetermined time period. The second predetermined time period may be determined based on a minimum time period that the obstruction must be removed before the alarm will be deactivated. For example, if the obstruction is only removed for a short time before being moved such that the air flow outlet is again obstructed, it may be not useful to deactivate the alarm until the obstruction is removed for a sufficient time so that any accumulated hotspots can dissipate.

As for the first predetermined time period, administrators of the data center may adjust this time period based at least in part on the configuration of the computing resources in the equipment racks and thermal characteristics of the equipment. For example, the first predetermined time period may be based on American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards for recommended temperatures, and the expected time that the recommended temperatures may be reached in the event of a blockage of the cooling airflow.

The alarm may be implemented to effectively warn local personnel that someone or some object is obstructing a cooling air outlet. Such alarms may include an audio alarm that provides aural warnings such as a siren or buzzer, a visual alarm that generates a flashing light or strobe, or various combinations thereof.

In at least some embodiments, a computing device that implements a portion or all of one or more of the technologies described herein, including the techniques to detect obstruction of cooling airflow, may include a general-purpose computer system that includes or is configured to access one or more computer-accessible media.FIG. 6illustrates such a general-purpose computing device600. In the illustrated embodiment, computing device600includes one or more processors610a,610b, and/or610n(which may be referred herein singularly as “a processor610” or in the plural as “the processors610”) coupled to a system memory620via an input/output (I/O) interface660. Computing device600further includes a network interface640coupled to I/O interface660.

In various embodiments, computing device600may be a uniprocessor system including one processor610or a multiprocessor system including several processors610(e.g., two, four, eight, or another suitable number). Processors610may be any suitable processors capable of executing instructions. For example, in various embodiments, processors610may be general-purpose or embedded processors implementing any of a variety of instruction set architectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. In multiprocessor systems, each of processors610may commonly, but not necessarily, implement the same ISA.

System memory620may be configured to store instructions and data accessible by processor(s)610. In various embodiments, system memory620may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or any other type of memory. In the illustrated embodiment, program instructions and data implementing one or more desired functions, such as those methods, techniques, and data described above, are shown stored within system memory620as code625and data626.

In one embodiment, I/O interface660may be configured to coordinate I/O traffic between processor610, system memory620, and any peripheral devices in the device, including network interface640or other peripheral interfaces. In some embodiments, I/O interface660may perform any necessary protocol, timing, or other data transformations to convert data signals from one component (e.g., system memory620) into a format suitable for use by another component (e.g., processor610). In some embodiments, I/O interface660may include support for devices attached through various types of peripheral buses, such as a variant of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard, for example. In some embodiments, the function of I/O interface660may be split into two or more separate components, such as a north bridge and a south bridge, for example. Also, in some embodiments some or all of the functionality of I/O interface660, such as an interface to system memory620, may be incorporated directly into processor610.

Network interface640may be configured to allow data to be exchanged between computing device600and other device or devices660attached to a network or network(s)650, such as other computer systems or devices as illustrated inFIGS. 1 through 6, for example. In various embodiments, network interface640may support communication via any suitable wired or wireless general data networks, such as types of Ethernet networks, for example. Additionally, network interface640may support communication via telecommunications/telephony networks, such as analog voice networks or digital fiber communications networks, via storage area networks, such as Fibre Channel SANs or via any other suitable type of network and/or protocol.

FIG. 7illustrates an example networked environment in which the embodiments described herein may be implemented.FIG. 7is a diagram schematically illustrating an example of data center operations710that can provide management of computing resources in a data center. Data center operations710may be configured to provide manage computing resources for executing applications on a permanent or an as-needed basis. The computing resources provided by data center710may include various types of resources, such as data processing resources, data storage resources, data communication resources, and the like. Each type of computing resource may be general-purpose or may be available in a number of specific configurations. For example, data processing resources may be available as virtual machine instances. The instances may be configured to execute applications, including web servers, application servers, media servers, database servers, and the like. Data storage resources may include file storage devices, block storage devices, and the like.

Data center operations710may include servers716aand716b(which may be referred herein singularly as “a server716” or in the plural as “the servers716”) that include various components such as storage devices717aand717b(which may be referred herein singularly as “a storage device717” or in the plural as “the storage devices717”). Other resources may be included in the servers such as processor blades770aand770b. Servers716aand716bshown inFIG. 7may be standard servers configured appropriately for providing the computing resources described above and may provide computing resources for executing one or more applications.

Referring toFIG. 7, communications network730may, for example, be a locally accessible network of linked networks. Communications network730may provide access to a system200for monitoring air flow obstructions as illustrated inFIG. 2.

A router714may be utilized to interconnect the servers716aand716b. Router714may also be connected to communications network730. Router714may manage communications within networks in data center operations710, for example, by forwarding packets or other data communications as appropriate based on characteristics of such communications (e.g., header information including source and/or destination addresses, protocol identifiers, etc.) and/or the characteristics of the private network (e.g., routes based on network topology, etc.). It will be appreciated that, for the sake of simplicity, various aspects of the computing systems and other devices of this example are illustrated without showing certain conventional details. Additional computing systems and other devices may be interconnected in other embodiments and may be interconnected in different ways.

It should also be appreciated that data center operations710described inFIG. 7is merely illustrative and that other implementations might be utilized. Additionally, it should be appreciated that the functionality disclosed herein might be implemented in software, hardware, or a combination of software and hardware. Other implementations should be apparent to those skilled in the art. It should also be appreciated that a server, gateway, or other computing device may comprise any combination of hardware or software that can interact and perform the described types of functionality, including without limitation desktop or other computers, database servers, network storage devices and other network devices, PDAs, tablets, cellphones, wireless phones, pagers, electronic organizers, Internet appliances, television-based systems (e.g., using set top boxes and/or personal/digital video recorders), and various other consumer products that include appropriate communication capabilities. In addition, the functionality provided by the illustrated modules may in some embodiments be combined in fewer modules or distributed in additional modules. Similarly, in some embodiments the functionality of some of the illustrated modules may not be provided and/or other additional functionality may be available.

The above described aspects of the disclosure have been described with regard to certain examples and embodiments, which are intended to illustrate but not to limit the disclosure. It should be appreciated that the subject matter presented herein extends to and encompasses such modifications and/or enhancements that will be apparent to persons skilled in the art in view of the detailed description provided herein.