SWITCHED DIRECT ATTACHED SHARED STORAGE ARCHITECTURE
20170364307 · 2017-12-21
Inventors
- Larry Lomelino (Folsom, CA, US)
- Christopher Christ (Folsom, CA, US)
- Gunneswara Rao Marripudi (Fremont, CA, US)
- Harry Laswell (Sacramento, CA, US)
- Steven Lahr (Auburn, CA, US)
Cpc classification
G06F13/102
PHYSICS
G06F3/0659
PHYSICS
G06F13/4022
PHYSICS
H04L12/4633
ELECTRICITY
H04L51/04
ELECTRICITY
H04L12/413
ELECTRICITY
H04L12/4641
ELECTRICITY
H04L67/1097
ELECTRICITY
G06F3/067
PHYSICS
International classification
Abstract
Various embodiments for implementing a switched direct attached shared storage architecture as disclosed herein include: providing a plurality of compute nodes, each compute node having integrated compute capabilities, data storage, and a network interface controller (Host NIC), the plurality of compute nodes being in data communication with each other via a local area network, the plurality of compute nodes each including distributed storage processing software resident thereon; providing a plurality of physical data storage devices in data communication with a storage controller; and enabling data communications in a data store switch fabric between the plurality of compute nodes and the plurality of physical data storage devices via the Host NIC and the storage controller, the data store switch fabric encapsulating data requests from the plurality of compute nodes into data frames for transport to corresponding physical data storage devices.
Claims
1. A switched direct attached shared data storage system comprising: a plurality of compute nodes, each compute node having integrated compute capabilities, data storage, and a network interface controller (Host NIC), the plurality of compute nodes being in data communication with each other via a local area network, the plurality of compute nodes each including distributed storage processing software resident thereon; a plurality of physical data storage devices in data communication with a storage controller; and a data store switch fabric enabling data communications between the plurality of compute nodes and the plurality of physical data storage devices via the Host NIC and the storage controller, the data store switch fabric encapsulating data requests from the plurality of compute nodes into data frames for transport to corresponding physical data storage devices, the data store switch fabric performing a virtual device to physical data storage device mapping and data striping on the physical data storage devices.
2. The system as claimed in claim 1 wherein the plurality of physical data storage devices is a plurality of solid-state drives (SSDs).
3. The system as claimed in claim 1 wherein the data store switch fabric is implemented using a protocol from the group consisting of: Ethernet and Peripheral Component Interconnect Express (PCIe).
4. The system as claimed in claim 1 wherein the data store switch fabric enables data communications between the plurality of compute nodes and the plurality of physical data storage devices in a manner to emulate a direct data connection.
5. The system as claimed in claim 1 wherein the data store switch fabric enables a distributed object store using an object tag format.
6. The system as claimed in claim 1 wherein the data store switch fabric overlaps processing operations to accelerate input/output operations between the plurality of compute nodes and the plurality of physical data storage devices using an Ethernet connection.
7. The system as claimed in claim 1 wherein the data store switch fabric can present a virtualization layer enabling the plurality of compute nodes to access the plurality of physical data storage devices in a virtual manner, the Host NIC presenting an endpoint to a corresponding compute node.
8. The system as claimed in claim 1 wherein the storage controller offloads a processing burden of the plurality of compute nodes, thereby allowing the plurality of compute nodes to write to a single data storage replica and have the corresponding data storage device automatically move the updated data to a designated replica within the data store switch fabric.
9. The system as claimed in claim 1 wherein the data store switch fabric implements a peer to peer (P2P) messaging protocol.
10. The system as claimed in claim 1 including an analytics framework to build an analytical model.
11. A method comprising: providing a plurality of compute nodes, each compute node having integrated compute capabilities, data storage, and a network interface controller (Host NIC), the plurality of compute nodes being in data communication with each other via a local area network, the plurality of compute nodes each including distributed storage processing software resident thereon; providing a plurality of physical data storage devices in data communication with a storage controller; and enabling data communications in a data store switch fabric between the plurality of compute nodes and the plurality of physical data storage devices via the Host NIC and the storage controller, the data store switch fabric encapsulating data requests from the plurality of compute nodes into data frames for transport to corresponding physical data storage devices, the data store switch fabric performing a virtual device to physical data storage device mapping and data striping on the physical data storage devices.
12. The method as claimed in claim 11 wherein the plurality of physical data storage devices is a plurality of solid-state drives (SSDs).
13. The method as claimed in claim 11 wherein the data store switch fabric is implemented using a protocol from the group consisting of: Ethernet and Peripheral Component Interconnect Express (PCIe).
14. The method as claimed in claim 11 wherein the data store switch fabric enables data communications between the plurality of compute nodes and the plurality of physical data storage devices in a manner to emulate a direct data connection.
15. The method as claimed in claim 11 wherein the data store switch fabric enables a distributed object store using an object tag format.
16. The method as claimed in claim 11 wherein the data store switch fabric overlaps processing operations to accelerate input/output operations between the plurality of compute nodes and the plurality of physical data storage devices using an Ethernet connection.
17. The method as claimed in claim 11 wherein the data store switch fabric can present a virtualization layer enabling the plurality of compute nodes to access the plurality of physical data storage devices in a virtual manner, the Host NIC presenting an endpoint to a corresponding compute node.
18. The method as claimed in claim 11 wherein the storage controller offloads a processing burden of the plurality of compute nodes, thereby allowing the plurality of compute nodes to write to a single data storage replica and have the corresponding data storage device automatically move the updated data to a designated replica within the data store switch fabric.
19. The method as claimed in claim 11 wherein the data store switch fabric implements a peer to peer (P2P) messaging protocol.
20. The method as claimed in claim 11 including providing an analytics framework to build an analytical model.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The various embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which:
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DETAILED DESCRIPTION
[0036] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the disclosed subject matter can be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the disclosed subject matter.
[0037] According to various example embodiments of the disclosed subject matter as described herein, there is provided a system and method for implementing a switched direct attached shared storage architecture. The various embodiments described herein provide a new data storage architecture to meet the above requirements to help enterprises extract value from the vast amounts of data they have been capturing. In today's market place, there are three markedly distinct solutions that try to address the above-listed requirements of growing needs of data storage and analysis. These three conventional solutions are listed below: [0038] 1. Cluster of nodes with integrated storage—In the storage industry parlance, this topology is often referred to as “Clustered Direct Attached Storage” (Clustered DAS or DAS) configuration; [0039] 2. Virtual Storage Area Network (VSAN); and [0040] 3. Shared storage connected over a network—In the storage industry parlance, this topology is often referred to as “Network Attached Storage” (NAS) or “Storage Area Networks” (SAN).
[0041] These three conventional solutions are each described in more detail in the following sections and illustrated in
Clustered DAS
[0042]
VSAN
[0043] A virtual storage area network (VSAN) is a collection of ports, from a set of connected switches, which form a virtual storage fabric. In general, a VSAN enables management software to serve data storage on cluster nodes to other cluster nodes.
NAS
[0044]
[0045] Each of the conventional data storage configurations described above are sub-optimal in addressing the growing data storage and analysis needs. The following table summarizes the challenges with DAS and NAS/SAN architectures in comprehensively meeting the solution requirements.
TABLE-US-00001 Solution Attribute DAS NAS/SAN Capacity Peta-bytes of capacity can Compute capacity can be be built using building built using building blocks blocks that have well- that have well-defined defined compute processing compute processing. This and storage capacity. This is usually achieved with a is usually achieved with a 2U server with 1 or 2 CPU 2U server with 1 or 2 CPU sockets and 12 drives for sockets and 12 drives for storage, with drives storage, with all drives sparsely populated. populated. Scalability The challenge is that the While this topology allows compute and storage compute and storage capacities can't grow capacities to grow independently of one independently of one another. This limits the another, the challenge is that expansion capabilities to the storage capacity will meet differing compute need to grow as a step and storage requirements function in increments of of multiple workloads controller head capability to sharing the cluster, and process data. This would would result in utilization result in overprovisioning inefficiencies, and utilization inefficiencies. Accessibility When expensive NAND Storage media is usually tied flash based storage media is to one or two controller used within a compute heads, and in the event of node, it's rendered useless cascading failures, the data when the compute node is could go out of access until down or disconnected from after a coarse granular the cluster due to some recovery takes place. unrelated hardware failures. Performance Given that storage media is Multiple protocol tied within a compute node translations are required as box, all remote access to it the data traverses from must go over a cluster compute node to the network typically shared controller head to the with other critical data physical storage media. This traffic among distributed introduces unnecessary workloads. This impacts performance overhead in performance both data and on network throughput and storage traffic. If physical compute capacity. This is resources are virtualized significantly exacerbated in in an attempt to address situations where the some of the accessibility compute cluster is running a issues discussed above, distributed processing it will result in additional framework that has built-in storage processing distributed storage overhead and increased semantics. In such network traffic. deployments, some of the work done in the controller head is unwarranted. Cost While acquisition costs for NAS/SAN solutions come this architecture could be with the controller head cheap, they do run into where intelligent software is other operational costs, run to manage the physical such as inability to power storage media. This usually down/hibernate some increases the cost of the unused compute nodes solution a lot more than the because it will take away cost of storage physical the attached storage from media. In deployments, the cluster. where there is enough compute capacity present to perform the data analysis, costs to cover the controller head become a necessary overhead that can be eliminated.
[0046] While DAS and NAS/SAN architectures can be used to build a data storage solution, these architectures fail to efficiently address the exponential growth in data storage and analysis needs. As the table below illustrates, these conventional architectures do not provide an efficient or optimal solution that addresses all the requirements without any trade-offs.
TABLE-US-00002 Solution Attribute DAS NAS/SAN Capacity Yes Yes Scalability No Maybe Accessibility No No Performance No No Cost Yes No
Switched Direct Attached Shared Data Storage Architecture
[0047] Referring now to
[0052] The Switched DAS architecture of an example embodiment has the flexibility to adapt to numerous underlying storage media interface protocols, and can also be extended to other clustering interconnect technologies via protocol encapsulation. The various embodiments described herein can be implemented with the most popular and standards based native storage media protocols, such as: NVMe (NVM Express), SAS/SATA, or SCSI over PCIe (SOP). NVM is an acronym for non-volatile memory, as used in SSDs. NVM Express is a specification for accessing solid-state drives (SSDs) attached through the PCI Express (PCIe) bus. Peripheral Component Interconnect Express (PCIe) is a high-speed serial computer expansion bus standard designed to replace older bus standards. Historically, most SSDs used buses, such as SATA (Serial ATA), SAS (Serial Attached Small Computer System Interface—SCSI), or Fibre Channel for interfacing with the rest of a computer system. SATA has been the most typical way for connecting SSDs in personal computers; however, SATA was designed for mechanical hard disk drives, and has become inadequate with SSDs. For example, unlike hard disk drives, some SSDs are limited by the maximum throughput of SATA. Serial Attached SCSI (SAS) is a point-to-point serial protocol that moves data to and from computer storage devices such as hard drives and tape drives. In an example embodiment, a data store switch fabric is implemented using Ethernet protocol and Ethernet data encapsulation. The following sections detail the specific procedures used in an example embodiment for: physical storage media assignment to compute nodes; data flow to/from the compute nodes and storage slices; and sharing of storage media in a Switched DAS cluster via a data store switch fabric.
Storage Assignment
[0053] Referring now to
[0054] As shown in
[0055]
[0056] Referring again to
[0057] Each of the storage containers 920 and 930 and compute nodes (902, 904, and 906) can be configured with the location of the physical hardware. Storage container to compute node assignment can use the physical location as required to manage the data accessibility in the presence of hardware failures. The same architecture, implemented with an Ethernet infrastructure as described herein, can be extended to use protocol specific identifiers and assignment with SAS/SATA protocols connected over an SAS expander, and SOP protocol connected over a PCIe switch.
Device Management
[0058]
[0059] In an example embodiment as shown in
[0060] If a drive is removed and then added back to the storage pool in a different location, the hash is again calculated to address into the Device ID Table. This time, the entry of the table is found to not be empty and the Device ID matches. The physical information of the new location of the device is added to the table.
[0061] When a drive that has otherwise been functioning as part of the storage pool is removed, the management entity of the local storage controller will hash into the device ID table removing the special location of the device from the table, but leaving the Device ID information in the table so the device can be identified if the device is returned to the storage pool.
Data Flow
[0062]
Sharing of Storage Media
[0063]
[0064] One of the key advantages of centralizing storage media is to enable dynamic sharing by cooperating compute nodes. The switched DAS architecture of the example embodiments enables this feature.
Switched DAS Using Ethernet
[0065] Referring again to
[0066] The architecture of the various example embodiments described herein eliminates complicated high latency IP (Internet Protocol) based storage protocol and its software based retries with long IO (input/output) time-outs. These protocols are used to work around Ethernet's lossy nature to create a reliable storage protocol.
[0067] The architecture of the various example embodiments described herein uses a data store switch fabric 160 to tunnel directly between nodes using server-based IO protocols across the network, resulting in directly exposing high performance storage devices 171 to the network. As a result, all the performance of the storage devices is made available to the network. This greatly benefits the compute server applications.
[0068]
[0069] Referring to
Storage Processing on Application Servers, with External Switch DAS
[0070] Referring again to
[0071] This result of overpriced and underperforming external data storage solutions led to a transition in the data center. Computer users moved storage internal to the compute or application servers. This solved the cost and performance issues they were experiencing with external storage. It worked great in smaller configurations. However, it is exceedingly difficult to support large compute environments with internal storage. Scaling storage independent of the compute environment is problematic. The density of the compute cluster is not optimal when placing storage in a server. Finally, the cost and performance of solid state devices is high enough that trapping devices in a single server, which is the least reliable portion of the system, is not cost effective and reduces overall system reliability.
[0072] The data storage architecture of an example embodiment described herein moves the SAN/NAS type of storage processing software onto the compute nodes. This removes both cost from the system as well as performance bottlenecks of the external SAN/NAS or object storage architecture. However, the architecture of the example embodiments utilizes externally switched DAS storage that exposes the performance of the drivers directly to a storage network. This allows for SAN/NAS type reliability, manageability, and availability that internal storage cannot offer. Removing storage from the compute servers now allows the compute environment and storage to scale independently. The removal of storage from the compute server allows for a more dense performance point. The density of the distributed storage solution of the example embodiments is far greater than that of internal storage, thereby reducing both power and footprint of the implementation.
Platform Software Architecture
[0073] The various example embodiments provide technology and a software platform for: instrumentation hooks to monitor, measure, and enforce performance metrics into the compute, memory, network and storage resources; and continuous monitoring of the health of all resources to predict failures and proactively adjust/update the cluster resources. Details of the software platform in an example embodiment are provided below.
Instrumentation Hooks to Monitor, Measure, and Enforce Performance Metrics into the Compute, Memory, Network and Storage Resources.
[0074] Referring to
[0075] A job's execution time for a job “j” is predicted based on: Tj=f (# of phases in the job, # of datasets the job is using, # of sub-task datasets the job will be split into, # of processing units assigned for the job, # of memory bytes assigned for the job, the worst case time for each of the sub-tasks, the average delay between phases, the average network throughput, the average disk throughput, the average disk input/output (IO) operations, etc.).
[0076] Referring now to
[0077] Referring now to
Continuous Monitoring of the Health of all Resources to Predict Failures and Proactively Adjust/Update the Cluster Resources
[0078] Referring to
[0079] Referring to
Input/Output (IO) Acceleration Using an Ethernet Connection
[0080] Referring to
Input/Output (IO) Virtualization Layer in an Ethernet Environment
[0081] Referring again to
Messaging Protocol
[0082] A low latency reliable secure messaging protocol is an important part of the data storage architecture described herein. The messaging protocol provided in an example embodiment uses the same connectivity infrastructure that customer IO operations use. The architecture of the protocol permits a responding compute server to directly send indexes and meta data to the locations where a requesting compute server will use the data, eliminating any memory copies. This saves valuable system bandwidth as well as increasing storage software performance. The messaging protocol also reduces system response latencies. Performance is also optimized as hardware can snoop the message entries while moving the data to obtain information used to ensure the memory integrity of the system receiving the indexes and meta data, thereby eliminating another queue or table.
[0083]
[0084] Referring to
Feature Offloads in an Ethernet Environment
[0085] Referring again to
[0086] Another class of offloads, which offload the processing burden of the compute cluster of servers, allows the compute servers to write to a single data storage replica and have this storage device automatically move the updated data to a designated replica within the storage network. This effectively eliminates the need to write to both the primary and the secondary storage device of a replica pair. A variation of the single write to a replica pair is to write two pieces of the updated information to each replica. The storage devices finish the transaction by sending the updated data they received to their mirrored device. This type of write method frees up bandwidth on specific links to the compute servers by allowing each transaction to go down a different path to the network. In a particular embodiment, multicast Ethernet packets can be used to send the same data to multiple destinations.
Storage Processing on Application Servers with External Switch DAS
[0087]
[0088] The organization of the blocks, pages, logical blocks, and erase blocks vary from generation to generation and vendor to vendor. The characteristics of the media will vary in an even greater manner as new non-volatile memory technologies appear.
[0089] As described herein, an example embodiment provides an IO layer that virtualizes the storage from the application or operating system and then optimizes that storage to get the best performance out of the media, particularly flash memory devices. The example embodiment enables the implementation to avoid the performance pitfalls, which can occur when the media is not used optimally.
[0090] With one interface, users can get the best out of flash memory devices from different generations of flash memory devices, different vendors, different drives, and even different non-volatile technology. This virtualization software layer that is flash memory device aware formats the physical media to optimize writes so as to limit the need for the flash memory devices to perform garbage collection. This is done by ensuring all files or records are flash erase bank aligned and a multiple of the erase bank size. Additionally, block size is a multiple of the erase bank size.
[0091] The ability to format a drive and write records with an erase buffer in mind also help reduce the need for spare pages. This frees up the pages from the spare pool and makes the pages available to customer applications. The example embodiment increases the density of a current flash device due to the optimized usage of the device. This creates a more cost effective solution for customers.
Input/Output (IO) Performance Optimizations Based on Workload
[0092] Today's storage stacks are developed to provide the optimal performance for an average IO and storage workload the system will see, or the user can force the system to use preferred settings. Some systems will allow the user to characterize their workloads and then the user can set the systems to use a given set of settings.
[0093] The various embodiments of the data storage system described herein are designed to enable adjusting to the IO traffic and storage characteristics as the traffic profile changes. The various embodiments can also be programmed to alert the operator or cluster management application when the traffic pattern is seen to cross preset limits. The various embodiments allow different segments of the storage to utilize completely different IO and storage logical block settings to optimize performance.
[0094] The feature of adjusting the configuration of the IO stack and hardware to the measured IO & storage traffic is coupled with the knowledge of the flash media described above in connection with
Flash Awareness and Failure Avoidance
[0095] The various embodiments described herein maintain real-time knowledge statistics of flash drives, which allows the system to avoid failures. Areas of the flash drives which are showing high levels of wearing (or bad cell sites) can be avoided when writing data. The cell use and the latency are monitored to determine wear. To monitor wear, data can be re-allocated to alternate drives and the storage meta data maintained on the compute nodes can be updated.
[0096] As individual flash drives near preset wear leveling targets, data can be slotted to other drives and meta data updated. If the user selects this feature, data can also be moved to alternate SSD's autonomously when these target thresholds are crossed. In addition, areas of the flash drives which are showing high levels of wearing (or bad cell sites) can be used for the storage of lightly written data (e.g., cold data storage). In this manner, the worn areas of the flash drives can still be used without wasting storage.
Storage Meta Data Structure
[0097] Referring again to
[0098]
Uses Cases of the Various Embodiments:
[0099] The Switched DAS architecture of an example embodiment has a wide variety of use cases. The following list presents a few of these use cases: [0100] 1. Using a distributed storage access layer across compute nodes—it could be used to build a scale-out cluster with centralized storage media to catering to Hadoop framework. [0101] 2. Using a distributed memory layer across compute nodes—it could be used to build a high-capacity shared memory running into 100′s of terabytes (TB) and more. [0102] 3. Using a distributed block storage access layer across compute nodes—it could be used to provide a storage backend for RDBMS (relational database management system) applications addressing OLTP/OLAP (online transaction processing/online analytical processing) transactions. [0103] 4. Using a distributed object storage access layer across compute nodes—it could be used to build a scale-out cloud storage server. [0104] 5. Using a distributed storage access layer across compute nodes—it could be used to build a VDI (virtual device interface) hosting server farm with integrated storage.
[0105]
An Example Embodiment Implementing Virtual to Physical Mapping and Data Striping
[0106]
[0107] The various embodiments described herein provide the capability to integrate switching into the data storage platform. This system structure and functionality provides several benefits over existing systems. These benefits include the following: [0108] Enables integration of Ethernet switching [0109] Saves cluster costs [0110] Does not require external switches [0111] Reduces operational costs [0112] Requires less physical space [0113] Reduces management costs [0114] Provides increased features and capabilities [0115] Provides the ability to monitor and control the entire storage solution
[0116] The architecture of the various example embodiments described herein uses a data store switch fabric 160 to tunnel directly between nodes using server-based IO protocols across the network, resulting in directly exposing high performance storage devices 171 to the network. As a result, all the performance of the storage devices is made available to the network. This greatly benefits the compute server applications. For particular example embodiments, the details of the tunnel flows and connection establishment are provided below.
Initial Connection Details
[0117]
TABLE-US-00003 Tunnel Connection Table (TCT) Remote MAC Local Tag Valid Remote Tag Address SSN RSN 0 1 8 00112233440004 123 8 1 1 5 00112233440015 54 38 2 1 31 00112233440009 0 249 . . . 0 . . . . . . . . . . . . 31 0 . . . . . . . . . . . . Local Tag: Tunnel Connection Table index (TCT Index). Valid: Indicates that the table index is valid. Remote Tag: Determined during Connection Establishment process. MAC Address: MAC address of remote device. SSN: Send Sequence Number. RSN: Receive Sequence Number, i.e. the next expected sequence number 3322 2222 2222 1111 1111 1100 0000 0000 1098 7654 3210 9876 5432 1098 7654 3210 CMD UA Tag Seq Num CMD: 1h ACK 2h NAK 4th Data 8 - Fh Messages/commands/completions. UA: Un-acknowledged packet. Packet will not be acknowledged by recipient and tunnel will do no tracking of it. If received by the destination, the packet will be pushed to the appropriate queue. TAG: 16 bit Tag of the local Tunnel Connection Table index of the packet receiver (the destination MAC Address of the packet). For unacknowledged packets, the TAG field is a don't care. SEQ: 8 Bit value to track ordering of packets on a connection. NUM For unacknowledged packets, the SEQ NUM is a don't care.
[0118] For particular example embodiments, the details of the features included in the hardware and data structures are provided below: [0119] a Connection Table [0120] Local Tag (TCT Index) to shadow data structure. [0121] UnAcknowledge (UACK) flag to shadow data structure. [0122] CSR Interface for HBA/FW to program TCT entries [0123] HBA/FW maintains and tracks in-use entries
[0124] For particular example embodiments, the details of the Outbound Request Flow are provided below: [0125] Tunnel Receives outbound request from upper level (cmd, completion, TLP) [0126] Shadow data contains LocalTag (TCT Index) [0127] Tunnel looks up TCT index finds remote tag and SSN [0128] the hardware inserts remote tag and current SSN and sends on ethernet or adds to pending send list
[0129] For particular example embodiments, the details of the Inbound Packet Flow are provided below: [0130] Tunnel Receives ethernet packet [0131] Tunnel Tag is the local TCT index [0132] Tunnel uses Tag to read TCT entry to find MAC Address, RSN, and the Remote Tag [0133] Tunnel confirms MAC Address and SN with values from TCT entry (or cached) [0134] Tunnel adds to reassembly list (out of order) or sends up the “stack”. [0135] Tunnel sends ACK/NAK. (Note: the Remote Tag is used in the ACK/NAK).
[0136] For particular example embodiments, the details of the Connection Establishment are provided below: [0137] Connection initiator Sends OpenConnection Cmd (HBA/ESP) [0138] Local tag is supplied in the payload of command [0139] UACK bit *set* in shadow data (tag value is don't care, because of UACK) [0140] Tunnel receives request and sends request with UACK bit set in Tunnel header [0141] Target Receives OpenConnection Command [0142] Tunnel logic detects UACK bit and sends straight up the stack (no ordering/ACKing checks). [0143] HBA/FW Determines if Tunnel Connection Resource available [0144] Allocates resource and programs TCT Entry. [0145] Sends completion (UACK bit set). Completion contains TCT Index (LocalTag). [0146] If no resource available, return error status. [0147] Connection initiator receives completion message to OpenConnection [0148] Completion contains RemoteTag (TCT Index from remote side) [0149] Initialize TCT Entry with Remote Tag, MAC [0150] Connection is ready for use. [0151] Connection Initiator sends ConnectionEstablished command [0152] UACK bit is *not* set [0153] Shadow data Tag field set to local TCT Index [0154] Connection Responder receives ConnectionEstablished command [0155] Sends completion (UACK bit) not set. [0156] Shadow data Tag field set to local TCT Index
[0157] For particular example embodiments, the details for handling a Simultaneous Open are provided below: [0158] Lowest MAC address wins. [0159] Higher MAC address sends Error Status (simultaneous open) [0160] Note: there is nothing in the architecture to prevent multiple connections between two devices, other than the lack of resources in hardware would require the resources to be used wisely.
[0161] For particular example embodiments, the details for handling Connection Tear Down are provided below: [0162] Closing device sends CloseConnection command [0163] Command is sent inside of the connection (UACK *not* set). [0164] Command payload contains local and remote tags of the connection. [0165] Closing device must quiesce all traffic to/from that connection prior to sending the CloseConnection command. [0166] Remote device receives CloseConnection [0167] Quiesce any outstanding traffic [0168] Send completion Message to CloseConnection [0169] Confirms completion is sent and ACK'd and then invalidates the TCT Entry. Need a way to confirm that Tunnel has received the ACK for the completion. [0170] Closing device receives completion [0171] Device invalidates the TCT Entry. [0172] If the ACK to the completion is lost, then retransmission of the completion after connection tear down will result in the completion being dropped.
[0173]
[0174] The example mobile computing and/or communication system 700 includes a data processor 702 (e.g., a System-on-a-Chip (SoC), general processing core, graphics core, and optionally other processing logic) and a memory 704, which can communicate with each other via a bus or other data transfer system 706. The mobile computing and/or communication system 700 may further include various input/output (I/O) devices and/or interfaces 710, such as a touchscreen display, an audio jack, and optionally a network interface 712. In an example embodiment, the network interface 712 can include a standard wired network interface, such as an Ethernet connection, or one or more radio transceivers configured for compatibility with any one or more standard wireless and/or cellular protocols or access technologies (e.g., 2nd (2G), 2.5, 3rd (3G), 4th (4G) generation, and future generation radio access for cellular systems, Global System for Mobile communication (GSM), General Packet Radio Services (GPRS), Enhanced Data GSM Environment (EDGE), Wideband Code Division Multiple Access (WCDMA), LTE, CDMA2000, WLAN, Wireless Router (WR) mesh, and the like). Network interface 712 may also be configured for use with various other wired and/or wireless communication protocols, including TCP/IP, UDP, SIP, SMS, RTP, WAP, CDMA, TDMA, UMTS, UWB, WiFi, WiMax, Bluetooth, IEEE 802.11x, and the like. In essence, network interface 712 may include or support virtually any wired and/or wireless communication mechanisms by which information may travel between the mobile computing and/or communication system 700 and another computing or communication system via network 714. Sensor logic 720 provides the sensor hardware and/or software to capture sensor input from a user action or system event that is used to assist in the configuration of the data storage system as described above.
[0175] The memory 704 can represent a machine-readable medium on which is stored one or more sets of instructions, software, firmware, or other processing logic (e.g., logic 708) embodying any one or more of the methodologies or functions described and/or claimed herein. The logic 708, or a portion thereof, may also reside, completely or at least partially within the processor 702 during execution thereof by the mobile computing and/or communication system 700. As such, the memory 704 and the processor 702 may also constitute machine-readable media. The logic 708, or a portion thereof, may also be configured as processing logic or logic, at least a portion of which is partially implemented in hardware. The logic 708, or a portion thereof, may further be transmitted or received over a network 714 via the network interface 712. While the machine-readable medium of an example embodiment can be a single medium, the term “machine-readable medium” should be taken to include a single non-transitory medium or multiple non-transitory media (e.g., a centralized or distributed database, and/or associated caches and computing systems) that store the one or more sets of instructions. The term “machine-readable medium” can also be taken to include any non-transitory medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the various embodiments, or that is capable of storing, encoding or carrying data structures utilized by or associated with such a set of instructions. The term “machine-readable medium” can accordingly be taken to include, but not be limited to, solid-state memories, optical media, and magnetic media.
[0176] Applications that may include the apparatus and systems of various embodiments broadly include a variety of electronic devices and computer systems. Some embodiments implement functions in two or more specific interconnected hardware modules or devices with related control and data signals communicated between and through the modules, or as portions of an application-specific integrated circuit. Thus, the example system is applicable to software, firmware, and hardware implementations.
[0177] In example embodiments, a node configured by an application may constitute a “module” that is configured and operates to perform certain operations as described herein. In other embodiments, the “module” may be implemented mechanically or electronically. For example, a module may comprise dedicated circuitry or logic that is permanently configured (e.g., within a special-purpose processor) to perform certain operations. A module may also comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. It will be appreciated that the decision to implement a module mechanically, in the dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations. Accordingly, the term “module” should be understood to encompass a functional entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired) or temporarily configured (e.g., programmed) to operate in a certain manner and/or to perform certain operations described herein.
[0178] While the machine-readable medium 704 or 708 is shown in an example embodiment to be a single medium, the term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable medium” shall also be taken to include any non-transitory medium that is capable of storing, encoding or embodying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies described herein. The term “machine-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical media, and magnetic media.
[0179] As noted, the software and/or related data may be transmitted over a network using a transmission medium. The term “transmission medium” shall be taken to include any medium that is capable of storing, encoding or carrying instructions for transmission to and execution by the machine, and includes digital or analog communication signals or other intangible media to facilitate transmission and communication of such software and/or data.
[0180] The illustrations of embodiments described herein are intended to provide a general understanding of the structure of various embodiments, and they are not intended to serve as a complete description of all the elements and features of components and systems that might make use of the structures described herein. Many other embodiments will be apparent to those of ordinary skill in the art upon reviewing the description provided herein. Other embodiments may be utilized and derived, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. The figures herein are merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
[0181] The description herein may include terms, such as “up”, “down”, “upper”, “lower”, “first”, “second”, etc. that are used for descriptive purposes only and are not to be construed as limiting. The elements, materials, geometries, dimensions, and sequence of operations may all be varied to suit particular applications. Parts of some embodiments may be included in, or substituted for, those of other embodiments. While the foregoing examples of dimensions and ranges are considered typical, the various embodiments are not limited to such dimensions or ranges.
[0182] The Abstract is provided to comply with 37 C.F.R. §1.74(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
[0183] In the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments have more features than are expressly recited in each claim. The following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
[0184] Thus, as described herein, a system and method for implementing a switched direct attached shared storage architecture are disclosed. Although the disclosed subject matter has been described with reference to several example embodiments, it may be understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the disclosed subject matter in all its aspects. Although the disclosed subject matter has been described with reference to particular means, materials, and embodiments, the disclosed subject matter is not intended to be limited to the particulars disclosed; rather, the subject matter extends to all functionally equivalent structures, methods, and uses such as are within the scope of the appended claims.