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The majority of Internet outages are directly attributable to software upgrade issues and software quality in general. Mitigation of network downtime is a constant battle for service providers.
Service providers not only incur downtime due to failures, but also incur downtime for upgrades to deploy new or improved software, hardware, software or hardware fixes or patches that are needed to deal with current network problems. A network outage can also occur after an upgrade has been installed if the upgrade itself includes undetected problems i.
Data merging, data conversion and untested compatibilities contribute to downtime. Upgrades often result in data loss due to incompatibilities with data file formats. Downtime may occur unexpectedly days after an upgrade due to lurking software or hardware incompatibilities. Often, the upgrade of one process results in the failure of another process. This is often referred to as regression. To avoid compatibility problems, multiple versions upgraded and not upgraded versions of the same software are not executed at the same time.
Most computer systems are based on inflexible, monolithic software architectures that consist of one massive program or a single image. Though the program includes many sub-programs or applications, when the program is linked, all the subprograms are resolved into one image.
Monolithic software architectures are chosen because writing subprograms is simplified since the locations of all other subprograms are known and straightforward function calls between subprograms can be used.
Unfortunately, the data and code within the image is static and cannot be changed without changing the entire image. Such a change is termed an upgrade and requires creating a new monolithic image including the changes and then rebooting the computer to datasheer it to use datashfet new.
Thus, to upgrade, patch or modify the program requires that the entire computer system be shut down and rebooted. To minimize the number of reboots required for software upgrades and, consequently, the amount of network down time, new software releases to customers are often limited to a few times a year at best. In some cases, only a single release per year is feasible. In addition, new software releases are also limited to a few times a year due to the amount of testing required to release a new monolithic software program.
As the size and complexity of the program grows, the amount of time required to test and the size of the regress matrix used to test the software also grows. Forcing more releases each year may negatively affect software quality as all bugs may not be detected. If the software is not fully tested and a bug is not detected—or even after extensive testing a bug is not discovered—and the network device is rebooted with the new software, datasgeet network down time may be experienced if the device crashes due to the bug or the device causes other devices on the network to have problems and it and other devices must be brought down again for repair or another upgrade to fix the bug.
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B56a4 addition, after each software release, the size of the monolithic image increases leading to a longer reboot time. Moreover, a monolithic image requires contiguous memory space, and thus, the computer system’s finite memory resources will limit the size of the image.
Unfortunately, limiting the number of software releases also delays the release of new hardware. An additional and perhaps less obvious issue faced by customers is encountered when customers need to scale and enhance their networks.
USB1 – Embedded database for computer system management – Google Patents
Typically, new and faster hardware is added to increase bandwidth or add computing power to an existing network. Under a monolithic software model, since customers are often unwilling to run different software revisions in each network element, customers are forced to upgrade the entire network. This may require shutting down and rebooting each network device.
The core or kernel software is loaded on power-up but the dynamic loading architecture allows each application to be loaded only when requested. Unfortunately, much of the data and code required to support basic system services, for example, event logging and configuration remain static in the kernel.
Application program interface API dependencies between dynamically loaded software applications and kernel resident software further complicate upgrade operations.
Consequently, many application fixes or improvements and new hardware releases, require changes to the kernel code which—similar to monolithic software changes—requires updating the kernel and shutting down and rebooting the computer.
In addition, processes in monolithic images and those which are dynamically loadable typically use a flat shared memory space programming model. If a process fails, it may corrupt memory used by other processes. Detecting and fixing corrupt memory is difficult and, in many instances, impossible. As a result, to avoid the potential for memory corruption errors, when a single datashest fails, the computer system is often re-booted. All of these problems impede the advancement of networks—a situation that is completely incongruous with the accelerated need and growth of networks today.
The present invention provides a network device having an internal configuration database process for managing configuration of dahasheet resources within the network device in response to configuration input provided by an external Network Management System NMS process. The network device can further include a plurality of modular processes that communicate with the configuration database to access configuration data, where the processes utilize the configuration data to modify execution behavior.
In one aspect, the invention provides a communications system having a network device that includes an internal configuration database process for managing configuration of internal resources within the network device.
The communications system further includes a computer system having an input mechanism for receiving configuration input data from a network manager, and a Network Management System NMS process for responding to the configuration input data and for sending configuration b5644a to the configuration database process within the network device.
The configuration database process within the network device configures internal resources of the network device in response to the configuration data received from the NMS.
The computer system of the communications system can further include an internal NMS database process for tracking configuration information stored by the configuration database within the network device. In one aspect, the configuration database, for any change to the configuration data stored by the configuration database, sends a notification of the change to the NMS database within the computer system to synchronize the NMS database with the configuration database.
A change notification, sent to the NMS database by the configuration database, can include data representing the change to the configuration data. In another aspect, the configuration database supports an active query feature and the NMS database is configured to establish an active query for all records within the configuration database to synchronize the NMS database with the embedded database.
The NMS process can communicate, for example, with the configuration database through a standard database protocol. The computer system of the communications system can be, for example, a workstation or a personal computer.
The network device can be, for example, a switch, a router, or a hybrid switch-router. The invention further provides a method of configuring a network device. The method calls for receiving configuration input data from a network manager through an input mechanism on a computer system independent of the network device.
The received configuration input data is adtasheet on to generate configuration data, and the configuration data is sent to a configuration database process within the network device. The internal resources within the network device are configured in response to the generated configuration data. The method can further include a step of sending notifications of changes to data stored within the configuration database to a Network Management System NMS database process executing on the computer system to synchronize the NMS database with the configuration database.
In another aspect, the method includes a step of executing an NMS process within the computer system, where sending the generated configuration data to the configuration database process includes using a standard database protocol. In yet daasheet aspect, the configuration database supports an active query feature and the method calls for establishing an active query for all records within the configuration database of the NMS database.
A modular software architecture solves datashet of the more common scenarios seen in existing architectures when software is upgraded or new features are deployed. Software modularity n564a functionally dividing a software system into individual modules or processes, which are then designed and implemented independently.
Inter-process communication IPC between the modules is carried out through message passing in accordance with well-defined application programming interfaces APIs.
A protected memory feature also helps enforce the separation of modules. Modules are compiled and linked as separate programs, and each program runs in its own protected memory space.
In addition, each program is addressed with an abstract communication handle, or logical name. The logical name is location-independent; it can live on any card in the system. Once complete, the processes continue to communicate with the same logical name, unaware of the fact that a switchover just occurred.
Like certain existing architectures, the modular software architecture dynamically loads applications as needed. Beyond prior architectures, however, the modular software architecture removes significant application dependent data from the kernel and minimizes the link between software and hardware. Instead, under the modular software architecture, the applications themselves gather necessary information i.
Metadata facilitates customization of the execution behavior of software processes without modifying the operating system software image. A modular software architecture makes writing applications—especially distributed applications—more difficult, but metadata provides seamless extensibility allowing new software processes to be added and existing software processes to be upgraded or downgraded while the operating system is running.
In one embodiment, the kernel includes operating system software, standard system services software and modular system services software. Even portions of the kernel may be hot upgraded under certain circumstances.
Examples of metadata include, customization text files used by software device drivers; JAVA class files that are dynamically instantiated using reflection; registration and deregistration protocols that enable the addition and deletion of software services without system disruption; and database view definitions that provide many varied views of the logical system model. Each of these and other examples are described below.
The embodiment described below includes a network computer system with a loosely coupled distributed processing system. It should be understood, however, that the computer system could also be a central processing system or a combination of distributed and central processing and either loosely or tightly coupled.
In addition, the computer system described below is a network switch for use in, for example, the Internet, wide area networks WAN or local area networks LAN. It should be understood, however, that the modular software architecture can be implemented on any network device including routers or other types of computer systems and is not restricted to a network dataxheet. A distributed processing system is a collection of independent computers that appear to the user of the system as a single computer.
In addition, computer system 10 includes multiple line cards 16 a — 16 n. Each line card includes a control processor subsystem 18 a — 18 nwhich runs an instance of the kernel 22 a — 22 n including slave and client programs as well as line card specific software applications.
Each control processor subsystem 1418 a — 18 n operates in an autonomous fashion but the software presents computer system 10 to the user as a single computer. Each control processor subsystem includes a processor integrated circuit chip 2426 a — 26 nfor example, a Motorola or an Intel Pentium processor.
The control processor subsystem also includes a memory subsystem 2830 a — 30 n including a combination of non-volatile or persistent e. B564s system 10 also includes an internal communication bus 32 connected to each processor 2426 a — 26 n. In one embodiment, the communication bus is a switched Fast Ethernet providing Mb of dedicated bandwidth to datassheet processor allowing the distributed processors to exchange control information at high frequencies.
A backup or redundant Ethernet switch may also be connected to each board such that if the primary Ethernet switch fails, the boards can fail-over fatasheet the backup Ethernet switch. In this example, Ethernet dataxheet provides an out-of-band control path, meaning that control information passes over Ethernet 32 but the network data being switched by computer system 10 passes to and from external network connections 31 a — 31 xx over a separate data path External network control data is passed from the line cards to the central processor over Ethernet This external network control data is also assigned the highest priority when passed over the Ethernet to ensure that it is not dropped during periods of heavy traffic on the Ethernet.
In addition, another bus daatsheet is provided for low level system service operations, including, for example, the detection of newly installed or removed hardware, reset and interrupt control and real time clock RTC synchronization across the system, In one embodiment, this is an Inter-IC communications I 2 C bus.
A managed device represents the top level system connected to models datashfet both hardware and software applications Hardware model includes models representing specific pieces of hardware, for example, chassisshelfslot and printed circuit board The logical model is capable of showing containment, that is, typically, there are many shelves per chassis 1: Nmany slots per shelf 1: N and one board per slot 1: Dataseet is a parent class having multiple shelf models, including various functional shelves a — n as well as one or more system shelves, for example, for fans and power Board is also a parent class having multiple board models, including various functional boards without ports a — n e.
Hardware model also includes a model for boards with ports coupled to the models for functional boards with ports and a port model