This disclosure generally relates to standardized frames or enclosures for mounting multiple information technology (IT) equipment modules such as a rack mount system (RMS) and, more particularly, to a rack having an optical interconnect system.
Rack mount network appliances, such as computing servers, are often used for high density processing, communication, or storage needs. For example, a telecommunications center may include racks in which network appliances provide to customers communication and processing capabilities as services. The network appliances generally have standardized heights, widths, and depths to allow for uniform rack sizes and easy mounting, removal, or serviceability of the mounted network appliances.
In some situations, standards defining locations and spacing of mounting holes of the rack and network appliances may be specified. Often, due to the specified hole spacing, network appliances are sized accordingly to multiples of a specific minimum height. For example, a network appliance with a minimum height may be referred to as one rack unit (1U) high, whereas the heights of network appliances having about twice or three times that minimum height are referred to as, respectively, 2U or 3U. Thus, a 2U network appliance is about twice as tall as a 1U case, and a 3U network appliance is about three times as tall as the 1U case.
A rack-based system including a rack carries information technology equipment housed in server sleds (or simply, sleds). A rack of the system includes multiple uniform bays, each of which is sized to receive a server sled. The system includes an optical network having optical interconnect attachment points at a rear of each bay and fiber-optic cabling extending from the optical interconnect attachment points to preselected switching elements. Multiple server sleds—including compute sleds and storage sleds—are slidable into and out from corresponding bays so as to connect to the optical network using blind mate connectors at a rear of each server sled.
Additional aspects and advantages will be apparent from the following detailed description of embodiments, which proceeds with reference to the accompanying drawings.
Some previous rack mount network appliances include chassis that are configured to house a variety of different components. For example, a rack mount server may be configured to house a motherboard, power supply, or other components. Additionally, the server may be configured to allow installation of expansion components such as processor, storage, or input-output (I/O) modules, any of which can expand or increase the server's capabilities. A network appliance chassis may be configured to house a variety of different printed circuit board (PCB) cards having varying lengths. In some embodiments, coprocessor modules may have lengths of up to 13 inches while I/O or storage modules may have lengths of up to six inches.
Other attempts at rack-based systems—e.g., designed under 19- or 23-inch rack standards or under Open Rack by Facebook's Open Compute Project (OCP)—have included subracks of IT gear mounted in the rack frame (or other enclosure) using a hodge-podge of shelves, rails, or slides that vary among different subrack designs. The subracks are then specifically hardwired (e.g., behind the rack wiring) to power sources and signal connections. Such subracks have been referred to as a rack mount, a rack-mount instrument, a rack mount system (RMS), a rack mount chassis, a rack mountable, or a shelf. An example attempt at a subrack for a standard 19-inch rack is described in the open standard for telecom equipment, Advanced Telecommunications Computing Architecture (AdvancedTCA®). In that rack system, each subrack receives cards or modules that are standard for that subrack, but with no commonality among manufacturers. Each subrack, therefore, is essentially its own system that provides its own cooling, power distribution, and backplane (i.e., network connectivity) for the cards or modules placed in the subrack.
In the present disclosure, however, a rack integrated in a cabinet has shelves that may be subdivided into slots to define a collection of uniform bays in which each bay accepts enclosed compute or storage units (i.e., sleds, also referred to as modules) so as to provide common cooling, power distribution, and signal connectivity throughout the rack. The integrated rack system itself acts as the chassis because it provides a common infrastructure including power distribution, cooling, and signal connectivity for all of the modules slid into the rack. Each module may include, for example, telecommunication, computing, media processing, or other IT equipment deployed in data center racks. Accordingly, the integrated rack directly accepts standardized modules that avoid the ad hoc characteristics of previous subracks. It also allows for live insertion or removal of the modules.
Structurally, the cabinet 100 includes a door 110 that swings to enclose the rack 106 within sidewalls 114 and a roof 116 of the cabinet 100. The door 110, sidewalls 114, roof 116, and a back side 118 having crossbar members and beams 820 (
The interior of the cabinet 100 has three zones. A first zone 126 on sides of the rack 106 extends vertically along the inside of the sidewalls 114 and provides for storage of optical and power cabling 128 within free space of the first zone 126. Also,
The compute sled 378 may contain a group of servers—such as, for example, a pair of dual Intel® Xeon® central processing unit (CPU) servers, stacked vertically on top of each other inside a housing 384—that are deployed together within the rack 106 as a single module and field-replaceable unit (FRU). Although the present disclosure assumes a compute sled contains two servers enclosed as a single FRU, the server group within a sled can be a different number than two, and there could be a different number of compute sleds per shelf (e.g., one, three, or four). For example, a sled could be one server or 4-16 microservers.
The sleds 268 and 378 offer benefits of modularity, additional shrouding for enhanced EMC, and cooling—but without adding the overhead and complexity of a chassis. For example, in terms of modularity, each sled contains one or more servers, noted previously, that communicate through a common optical interconnect at a back side of the sled for rack-level I/O and management. Rack-level I/O and management are then facilitated by optical cabling (described in detail below) extending within the cabinet 100 between a blind mate socket and the switches, such that preconfigured connections are established between a sled's optical interconnect and the switches when a sled is slid into the rack 106. Relatedly, and in terms of shrouding, front faces of sleds are free from cabling because each sled's connections are on its back side: a sled receives from a PSU power delivered through a plug-in DC rail (in the rear of each sled). Cooling is implemented per-sled and shared across multiple servers within the sled so that larger fans can be used (see, e.g.,
In this example, each rack can be equipped with a variable number of management plane and data plane switches (ToR switches). Each of these aggregate management and data traffic to internal network switch functions, as follows.
With reference to the primary data plane switch 844, all servers in the rack connect to the downlinks of the primary data plane switch using their first 10 GbE (Gigabit Ethernet) port. The switch uplink ports (40 GbE) provide external connectivity to a cluster or end-of-row (EoR) aggregation switches in a datacenter.
With reference to the secondary data plane switch 846 (see, e.g., “Switch 2” of
With reference to the device management switch 848 (see, e.g., “Switch 3” of
With reference to the application management switch 856 (see, e.g., “Switch 4” of
Although the switch topology is not a fixed system requirement, a rack system will typically include at least a device management switch and primary data plane switch. Redundancy may or may not be part of the system configuration, depending on the application usage.
Advanced TCA and other bladed telecom systems have a backplane that provides the primary interconnect for the IT gear components. Backplanes have an advantage of being hot swappable, so that modules can be replaced without disrupting any of the interconnections. A disadvantage is that the backplane predefines a maximum available bandwidth based on the number and speed of the channels available.
Enterprise systems have also used patch panel wiring to connect individual modules. This has an advantage over backplanes of allowing channels to be utilized as needed. It has a disadvantage in that, during a service event, the cables have to be removed and replaced. And changing cables increases the likelihood of operator-induced system problems attributable to misallocated connections of cables, i.e., connection errors. Also, additional time and effort would be expended removing and replacing the multiple connections to the equipment and developing reference documentation materials to track the connections for service personnel.
In contrast,
A group of servers within a sled share an optical interconnect (blind mate) interface that distributes received signals to particular servers of a sled, either by physically routing the signals to a corresponding server or by terminating them and then redistributing via another mechanism. In one example, four optical interfaces are split evenly between two servers in a compute sled, but other allocations are possible as well. Other embodiments (e.g., with larger server groups) could include a different number of optical interconnect interfaces. In the latter case, for example, an embodiment may include a so-called microserver-style sled having several compute elements (e.g., cores) exceeding the number of available optical fibers coming from the switch. In such a case, the connections would be terminated using a local front end switch and would then be broken down into a larger number of lower speed signals to distribute to each of the cores.
The location of the blind mate connector 1300 provides multiple benefits. For example, the fronts of the sleds are free from cables, which allows for a simple sled replacement procedure (and contributes to lower operational costs), facilitates hot swappable modules of various granularity (i.e., computing or storage servers), and provides optical interconnects that are readily retrofitted or otherwise replaced.
Once a (new) sled is plugged in, it is automatically connected via the preconfigured optical interconnect to the correct switching elements. It is booted and the correct software is loaded dynamically, based on its position in the rack. A process for dynamically configuring a sled's software is described in the following paragraphs. In general, however, sled location addressing and server identification information are provided to managing software (control/orchestration layers, which vary according to deployment scenario) so that the managing software may load corresponding software images as desired for configuring the sled's software. Sleds are then brought into service, i.e., enabled as a network function, by the managing software, and the rack is fully operational. This entire procedure typically takes a few minutes, depending on the software performance.
Initially, at a high level, a user, such as a data center operator, is typically concerned with using provisioning software for programming sleds in the rack according to the sled's location, which, perforce, gives rise to a logical plane (or switching zone) established by the preconfigured optical fiber connections described previously. The identification available to the provisioning software, however, is a media access control (MAC) address. Although a MAC address is a globally unique identifier for a particular server in a sled, the MAC address does not itself contain information concerning the sled's location or the nature of its logical plane connections. But, once it can associate a MAC address with the sled's slot (i.e., its location in the rack and relationship to the optical network), the provisioning software can apply rules to configure the server. In other words, once a user can associate a sled location to a MAC address (i.e., a unique identifier), the user can use any policies it wants for setup and provisioning sleds in the slots. Typically, this will include programming the sled in the slots in specific ways for a particular data center operating environment.
Accordingly, each switch in the rack maintains a MAC address table that maps a learned MAC address to a port on which the MAC address is detected when a sled is powered on and begins transmitting network packets in the optical network. Additionally, a so-called connection map is created to list a mapping between ports and slot locations of sleds. A software application, called the rack manager software, which may be stored on a non-transitory computer-readable storage device or medium (e.g., a disk or RAM) for execution by a processing device internal or external to the switch, can then query the switch for obtaining information from its MAC address table. Upon obtaining a port number for a particular MAC address, the rack manager can then use the connection map for deriving the sled's slot location based on the obtained port number. The location is then used by the rack manager and associated provisioning software to load the desired sled software. Additional details on the connection map and rack manager and associated provisioning software are as follows.
The connection map is a configuration file, such as an Extensible Markup Language (XML) formatted file or other machine-readable instructions, that describes how each port has been previously mapped to a known corresponding slot based on preconfigured cabling between slots and ports (see, e.g.,
If a port lacks an entry in the connection map, then it is assumed that the port is unused. For example, some port numbers are missing in the example table because, in this embodiment of a connection map, the missing ports are unused. Unused ports need not be configured.
The slot number in the foregoing example is the lowest numbered slot occupied by the sled. If the height of a sled spans multiple slots (i.e., it is greater than 1U in height), then the slot positions occupied by the middle and top of the sled are not available and are not listed in the connection map. For example, the sled in slot 15 is 2U in height and extends from slot 15 to 17. Slot 16 is not available and is therefore not shown in the connection map. Slots ending in “0.2” indicate a side of a half-width shelf.
“Part No.” is a product identification code used to map to a bill of materials for the rack and determine its constituent parts. The product identification code is not used for determining the slot position but is used to verify that a specific type of device is installed in that slot.
The rack manager software application may encompass functionality of a separate provisioning software application that a user of the rack uses to install operating systems and applications. In other embodiments, these applications are entirely separate and cooperate through an application programming interface (API) or the like. Nevertheless, for conciseness, the rack manager and provisioning software applications are generally just referred to as the rack manager software. Furthermore, the rack manager software may be used to set up multiple racks and, therefore, it could be executing externally from the rack in some embodiments. In other embodiments, it is executed by internal computing resources of the rack, e.g., in a switch of the rack.
Irrespective of where it is running, the rack manager software accesses a management interface of the switch to obtain a port on which a new MAC address was detected. For example, each switch has a management interface that users may use to configure and read status from the switch. The management interface is usually accessible using a command line interface (CLI), Simple Network Management Protocol (SNMP), Hypertext Transfer Protocol (HTTP), or other user interface. Thus, the rack management software application uses commands exposed by the switch to associate a port with a learned MAC address. It then uses the port to do another lookup from the connection map of the slot number and server number. In other words, it uses the connection map's optical interconnect configuration to heuristically determine sled positions.
After the rack manager software has obtained port, MAC address, server function, and slot location information, it can readily associate the slot with the learned MAC address. With this information in hand, the correct software is loaded based on the MAC addresses. For example, the Preboot Execution Environment (PXE) is an industry standard client/server interface that allows networked computers that are not yet loaded with an operating system to be configured and booted remotely by an administrator. Another example is the Open Network Install Environment (ONIE), but other boot mechanisms may be used as well, depending on the sled.
If the cabling on the rack is changed, then the connection map is edited to reflect the cabling changes. In other embodiments, special signals carried on hardwired connections may be used to determine the location of sleds and thereby facilitate loading of the correct software.
Skilled persons will understand that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure. The scope of the present invention should, therefore, be determined only by the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/304,090, filed Mar. 4, 2016, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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62304090 | Mar 2016 | US |