Note: Descriptions are shown in the official language in which they were submitted.
CA 02330355 2001-O1-25
METHOD AND APPARATUS FOR MANAGING A
COMPUTER NETWORK
This is a division of Canadian Application Serial No. 2,241,003
which is the national phase application of PCT International
Application Serial No. PCT/LJS96/20104 filed December 20, 1996.
FIELD OF THE INVENTION
The present invention pertains to the field of computer
networking. More particularly, the present invention relates to tools for
providing management services for a computer network.
BACKGROUND OF THE INVENTION
The rapidly increasing use of personal computers has created a
growing interest worldwide in computer networking, a prime example
of which is the pervasive use of "the Internet". Computer networking
on a smaller scale, such as in the form of Local Area Networks
(LANs), has also expanded into countless different areas of business
and technology. As users place more reliance upon computer networks,
however, they also demand more sophisticated capabilities for
managing these networks. Various different software packages exist
for providing users with such capabilities.
Existing software products for network management have
several disadvantages, however. For example, such products tend to be
largely "tool-based". That is, although the software provides the user
(e.g., a network administrator) with a set of tools for performing
network functions, such as troubleshooting, it is often up to the user to
determine which tool is best for performing a particular task and to
determine on which devices in the network a task should be performed.
Further, it is often difficult for a network administrator or user to
become proficient enough with the available management
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tools to be able to use those tools to their full potential. These tools
also tend to require that the user have extensive knowledge about the
layout of the network, and that the user provide this information to
the management tool. Moreover, existing network management tools
generally provide the user with only one or two predetermined
formats for examining the layout of the network.
Hence, what is needed is a set of network management services
which are designed from a more flexible, device-oriented perspective.
Specifically, what is needed is a network management tool which
provides the user with information on the layout of the network,
tasks that can be performed, and the devices on which each particular
task can be performed. What is further needed is a tool which
provides the user with customizable ways of viewing the layout of the
network.
SUMMARY OF THE INVENTION
A computer-implemented method of providing information
on a computer network is provided. The network includes a number
of devices. A number of tasks are provided, such that each task can be
performed upon at least one of the devices. In the method, a display is
generated having a first area corresponding to the devices and a
second area corresponding to the tasks. A representation of a subset of
the plurality of devices is displayed in the first area. A user input
selecting the representation is accepted, and, in response to the user
CA 02330355 2001-O1-25
input, information indicating which of the tasks can be performed upon
each device of the subset is displayed in the second area.
Accordingly, in one aspect, the present invention provides a
machine-readable program storage medium tangibly embodying
sequences of instructions, the sequences of instructions for execution
by at least one processing system to perform steps for defining a
schema for a database, the database for storing a physical model of a
computer network, the computer network including a plurality of
devices, said steps comprising: defining a device object type for
representing the devices; defining a task object type for representing a
plurality of tasks, each of the tasks performable on at least one of the
devices; and defining a group object type for representing a plurality of
groups, such that each of the groups may have at least one of the
devices as a member, such that each of the groups may have at least
one of the tasks as a member, and such that any of tasks which is a
member of one of the groups is performable on each device that is a
member of said group.
Other features of the present invention will be apparent from the
accompanying drawings and from the detailed description which
follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not
limitation in the figures of the accompanying drawings, in which like
references indicate similar elements and in which:
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3a
Figure 1 illustrates a computer network in which the present
invention can be implemented.
Figure 2A illustrates a logical view display having a device
window and a task window.
Figure 2B illustrates a display consisting of a tree hierarchy of
devices.
Figure 3 is a block diagram of core services for managing a
network.
Figure 4 is a block diagram of a discovery manager core service.
Figure 5 is an object relationship model (ORM) diagram
showing a metaschema of a database engine according to the present
invention.
Figure 6 is a block diagram of a physical network model core
service.
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Figure 7 is an object relationship model (ORM) diagram of a
physical network model schema.
Figure 8 illustrates a graph representing network configuration
information stored in accordance with the present invention.
Figure 9 is a block diagram of a view generator core service.
Figure 10 is a flowchart depicting the overall operation of core
services for managing a network in accordance with the present
invention.
Figure 11 is a flowchart depicting the steps performed during
the network discovery process by core services in accordance with the
present invention.
Figure 12 is a flowchart illustrating the steps for calculating the
tasks for a selected device or group.
Figure 13 is a flowchart illustrating the steps for calculating
tasks for a group.
Figure 14 is a flowchart illustrating the steps for calculating the
tasks for a given device.
Figure 15 is a flowchart illustrating the steps for calculating
tasks of a component.
DETAILED DESCRIPTION
A method and apparatus for providing management services
for a computer network is described. In the following description, for
purposes of explanation, numerous specific details are set forth in
order to provide a thorough understanding of the present invention.
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It will be evident, however, to one skilled in the art that the present
invention may be practiced without these specific details. In other
instances, well-known structures and devices are shown in block
diagram form in order to avoid unnecessarily obscuring the present
invention.
The present invention includes steps for providing a number of
core services for managing a computer network, such as a local area
network (LAN). The steps may be performed by a general purpose
processor programmed with instructions that cause the processor to
perform the recited steps. The instructions may be stored in a
memory or on a magnetic disk, CD-ROM, or any other mass storage
device. Alternatively, the steps may be performed by specific
hardware components that contain hard-wired logic for performing
the recited steps, or by any combination of programmed general
purpose computer components and custom hardware components.
As illustrated in Figure 3, the core services 300 include a
discovery manager 301, a database engine 302, a physical network
model 303, a view generator 304, and a task manager 305. The core
services 300 provide a user, such as a LAN administrator, with
customizable views of the layout of a network, the various network
management tasks that can be performed on devices in the network,
and the particular devices on which each task can be performed. It
should be noted that, for purposes of this description, the term
"device" may refer to either a physical device or a logical device.
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The functions and information provided by the core services
300 are presented through a graphical user interface. Accordingly, the
present invention is designed to operate in a windows-and-icons
environment. Specific methods for implementing a windows-and-
icons environment are well known in the computer art and therefore
will not be described herein. The present invention also operates in
conjunction with an operating system and system functions capable of
displaying windows, graphical and textural information within
windows, and cursor symbols on the display device. System functions
for interfacing with a mouse and cursor function keys are also
required. These resources are standard processing components which
are also well known in the computer art.
Figure 1 illustrates a computer network 10 in which the present
invention may be implemented. The network 10 includes a number
of individual computer systems I2, I5, and 20. These computer
systems include personal computer (PC) systems 20 that are clients of
either a management server 12 or a managed server 15. Although
many servers may be present in the network 10, only one server, the
management server 12, is required in order to implement the present
invention. At least some of the services, including control software
for coordinating the various services, are implemented within the
management server 12. The managed server 15 represents any server
in the network 10 other than the management server 12. It should be
appreciated that, in any given network in which the present
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invention is implemented, there may be multiple management
servers 12 or managed servers 15.
As will be described in greater detail below, the core services
gather data, either periodically or in response to a user command,
about the current physical and logical layout of the network. This
data, which includes the types of devices in the network, the quantity
of each type of device, and their connectivity, is then stored in a
database representing a network "map". In addition, the core services
gather and maintain data regarding tasks which can be performed
upon each of the devices. Tasks are actions that can be taken to
troubleshoot, monitor, or report on devices in the network. Some
examples of tasks which might be performed on various devices in a
network are: viewing the screen of a particular PC; displaying packet
counts; running a report; executing a remote virus scan; rebooting
selected workstations; displaying print jobs; or, displaying non-
functioning printers.
A display, referred to in this description as the "logical view",
shows symbolically the devices in the network and associated
performable tasks. In one embodiment, the devices are shown as part
of a hierarchical structure based on the stored network map. Devices
can be organized into various device groups, which are user-definable,
and tasks can be organized into various user-definable task categories,
which are also user-definable. The user may initiate any of the
displayed tasks by applying a user input via a "control panel" screen
(e.g., by double-clicking on a task icon with a mouse).
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I. User Interface
Figure 2A illustrates an example of a logical view 200 display for
a typical network. The logical view 200 includes a device window 201
and a task window 202. Devices and device groups in the network are
represented in the device window 201. Each group and each device is
represented with its name and a bitmap (icon). For example, device
window 201 includes bitmaps 205, 207, and 208 representing the "PC"
group, the "Printer" device group, and the "Server" device group,
respectively. Double-clicking on a group bitmap with a cursor control
device (e.g., a mouse, trackball, etc.) will cause that group to be
expanded in the device window 201 into a tree hierarchy consisting of
all devices within that group. For example, "Guest" 206 and "User 1"
210 are displayed descending from "PC" 205, because those devices are
members of the "PC" group.
The task window 202 displays the tasks and categories of tasks
that can be performed on a particular device or group which has been
selected in the device window 201. For example, the tasks and task
categories displayed in task window 202 represent tasks/categories that
can be performed upon the device "User 1", the bitmap 206 of which
has been selected (and is therefore enclosed by a box) within the device
window 201. In the task window 202, tasks 211, 212, and 213 ("Display
packet counts", "Filter on selected IPX protocol devices", and "Show
print jobs belonging to selected user", respectively) each are members
of the task category "Monitor" 209. Selecting a different device or
group in the device window 201 will cause a different set of
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tasks/categories to be displayed corresponding to the selected device or
group.
The user can cause any displayed task to be performed upon a
device. A task is initiated by the user's selecting the bitmaps of the
desired task and the device or group upon which the task is to be
performed, and then entering a predetermined user input, such as
selecting an option from a pull-down menu, or double-clicking with
the cursor control device on one of the tasks.
In one embodiment of the present invention, the device
window 201 displays a tree hierarchy showing the logical or physical
connection of all devices in the network, organized into device
groups. Figure 2B shows an example of a display consisting of a tree
hierarchy of devices, as represented by their bitmaps and names. Each
of the devices belongs to the group "Server". The group "Server"
includes a device "Server 1". Devices "NIC" (Network Interface Card)
and "USER Agent" are components of the device "Server 1" and are
therefore displayed with their names enclosed by the symbols "< >".
Devices "GUEST", "SUPERVISOR", "User 1", and "User 2" are
attached to (but not components of) device "Server 1". A second
"NIC" is a component of device "User 2". It should be appreciated that
alternative embodiments of the present invention might include
schematic, geographic, or other views of the layout of the network, in
addition to or instead of a tree hierarchy view.
CA 02330355 2001-O1-25
II. System Architecture
As illustrated in Figure 3, the software of the present invention
comprises several core services 300 implemented as distinct modules,
which include a discovery manager 301, a database engine 302, a
physical network model 303, a view generator 304, and a task manager
305. In general, the discovery manager 301 gathers real-time data
about the devices in the managed network 10 and coordinates access to
both historical network data and the real-time device data. The
database engine 302 provides a logical database structure for storage of
network device and task data. The database engine 302 also supports a
query mechanism adequate for the needs of various client software
applications, such as an inventory management application. Further,
the database engine 302 allows client applications to define fields to be
stored in a way that is appropriate for each such application. The
physical network model 303 includes the actual database and uses the
database engine 302 to provide storage and retrieval of network device
information for the discovery manager 301. The physical network
model 303 represents all known pieces of the managed network 10 and
how those pieces interrelate. In some embodiments of the present
invention, the physical network model 303 may provide means for
client applications to add, modify, and remove devices and the
relationships between devices, and provide, in response to a user
request, lists of devices with a given relationship to a device or other
list of devices. The view generator 304 provides a flexible, user-
defined listing of devices in the network 10 and available tasks, which
CA 02330355 2001-O1-25
may be displayed in the logical view 200. The LAN Administrator can
arrange devices in different ways to provide the most useful
presentation of network organization. Finally, the task manager 305
maintains knowledge of all executable tasks in the network and the
devices on which such tasks can be performed and initiates tasks in
response to user commands.
The overall operation of the core services 300 is illustrated in
the flowchart of Figure 10. The discovery manager 301 determines,
either periodically or in response to a user query, the logical (and,
optionally, the physical) configuration of the network (step 1001) and
stores this configuration information in the database of the physical
network model 303. The task manager 305 determines the valid tasks
for the network (i.e., tasks that are performable on at least one device
in the network) (step 1002) and associates each valid task with the
particular devices and groups of devices on which each such task can
be performed (step 1003). If a display is requested by the user (step
1004), the logical view Z00 is updated and displayed (step 1005) by the
view generator 304. The process is then repeated periodically based on
a user-defined update frequency (step 1006).
A. Discovery Manager
The Discovery Manager provides data on devices that are
currently connected in the network as well as historical information
about devices that have been connected and available in the past.
Figure 4 shows a block diagram of the discovery manager 301. The
CA 02330355 2001-O1-25
discovery manager includes a control module 310, a number of
discovery modules 312, and a discovery application programming
interface (API) 311. The various discovery modules 312 poll the
network 10 to find specific types of devices. Each discovery module is
a specialist in finding a certain type of device, although there may be
overlap in the particular devices found by different discovery
modules. When a device is found by a discovery module 312, that
module then adds information about the device to the physical
network model 303. Referring again to Figure 1, the discovery
modules 312 may be implemented on the management server 12, or
they may be distributed between amongst two or more of the
computers on the network I0. The presence of a module for
discovering a particular type of device is recorded in a configuration
file for use by the discovery control module 310.
The control module 310 and the API 311 are implemented on
the management server 12. The control module 310 provides
scheduling for the polling of the network performed by the discovery
modules 312. The control module 310 also handles user requests for
information about devices. The control module 310 can satisfy such
requests by searching for devices in the physical network model 303,
running one or more discovery modules 312, or both, as needed. The
discovery control module 310 determines which discovery module to
run by searching for entries in the configuration file that indicate the
device type and the name of the corresponding discovery module to
run. Thus, the network can be polled automatically by the discovery
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manager 301 on a periodic basis, where the period can be user-defined,
or manually in response to a user's query.
The discovery API 311 provides a functional interface between
the operating system of the management server 12 and the control
module 310. In the discovery API 311, any functions which return
lists of devices or data about a device include a parameter which
informs the discovery manager whether to look in the physical model
database for the current state of the network, historical data, or both, to
supply the list of devices. In either case, the devices identified will be
in the database (either the devices were already present or the
discovery module placed them there in response to the function being
called) and applications can obtain information about them.
The functions of the discovery API 311 which can retrieve real-
time data are:
Get Device Attribute
List Devices
List Device Attributes
List Devices with Attribute
List Devices With Attribute Value
List Linked Devices
List Group Members
The terms "attribute", "attribute value", and the concept of "linked"
devices are explained below. Other functions of the discovery API 311
include:
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Add Device (to physical network model)
Update Device
Add Device to Group
List Group Members
Figure 11 provides a flowchart of the steps performed iri the
discovery process. Note that the responsibility for performing these
steps may be distributed between various computers in the nehvork.
Based on the scheduling provided by the control module 310, the
individual discovery modules 312 each poll the network for specific
types of devices (steps 1101 and 1102). In order to be recognized as part
of the network, a given device must provide at least the attributes
belonging to a predefined set of attributes for that device type. When a
particular device is found, the corresponding discovery module 312
identifies any key attribute values of that device (step 1104) and adds
the device and those values to the database (step 1105).
B. Database Engine
As noted above, the database engine 302 supports a query
mechanism for use by various client applications. In addition, the
database engine allows client applications to define fields to be stored
in an appropriate way for each such application. The database will
store data efficiently even though the fields of a record are not defined
until the core services 300 are actually put into use. Accordingly, the
database engine 302 embodies a database schema that is used to define
another, more specialized database schema. More specifically, the
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database engine 302 embodies a metaschema that is used to define the
more-specialized schema, which is described below, that is the
foundation of the physical network model 303.
Figure 5 is an object relationship model (ORM) diagram
conceptually showing the components of the database engine's
metaschema and their relationships to each other. The primary
storage unit of the database is an object 600. In the ORM diagram in
Figure 5, rectangles represent object classes, lines represent
relationships between objects, a diamond indicates a ternary
relationship, an unfilled triangle represents the concept of
specialization, and a filled triangle represents the concept of
aggregation. An object 600 has an object type 601 associated with it,
which is registered by the user. Each object type 602 has an object type
name 602. An object 600 also has a link 603 of a specific link type 603
to another object 600. Link types 603 are registered by the user and
may represent any logical connection or relationship the user wishes.
Two objects 600 may have multiple links, but each link must be of a
different link type 603. Each link type 603 has a link type name 603.
Examples of some possible link types are: IPX (i.e., a communication
protocol), physical component, logical component, and ethernet. Link
records may be stored in a separate table from the object records for
improved efficiency.
Attributes 605 are used for attaching data selected by the user
(e.g., an device address, a mail center, etc.) to objects 600. Attributes
605 are optional fields, in that they can be used for only selected
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devices. Attributes 605 are also the criteria which are used in
determining if a device is recognized by the discovery manager 301 as
part of the network, as will be described below. In order to be
recognized as part of the network, a given device must provide at least
the attributes that have been previously defined for a given device
type. An attribute 605 is a specialization of an object 600. In addition,
an attribute 605 is an aggregation of an attribute type 606, which is
registered by the user, and an attribute value 607. Objects 600 are
therefore linked to attributes 605. Each attribute type 606 has an
attribute type name 608.
C. Physical Network Model
The physical network model (PNM) 303 represents all known
pieces of the managed network 10 and how those pieces interrelate.
Referring to Figure 6, the PNM 303 includes a PNM Manager 331, a
PNM API 332 functionally coupled to the discovery manager 301, and
a physical model database 333 driven by the database engine 302. The
PNM 303 provides storage in the physical model database 333 of the
real-time and historical network information acquired by the
discovery modules 312. The stored information includes the devices,
device types, device attributes, and relationships between devices in
the network. Devices are represented in the physical model database
333 as objects (see Figure 4) and relationships are represented as links.
The PNM 303 further provides means for client applications to add,
modify, and remove devices and relationships between devices. The
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PNM 303 further provides, in response to user requests, lists of devices
with a specified relationship to a device or other list of devices.
To represent the physical organization of a network, the PNM
303 uses a list of all devices which have been discovered by the
Discovery Manager 301 and maintains within the physical model
database 333 information on how each device is connected to each
other device. This connectivity information may include such
information as the fact that a device is physically installed in the same
box as another device, a client/server relationship, or any other
connection type that could be useful to an application. The complete
physical model database 333 represents a graph (i.e., a numerical
model) in which the nodes in the graph represent devices and the
connection between the nodes represents the connections between the
devices. Standard graph theory may be used to find various
relationships between nodes, such as the shortest path, cycles,
connectivity, and optimization.
Figure 8 illustrates how a typical network might be stored and
the various connections determined in the PNM database 333 using
this approach. The network of Figure 8 includes a segment 801 and a
segment 812. A segment generally represents any physically or
logically contiguous part of a network. Devices which are shown (and
therefore stored) as linked to a particular segment reside on that
segment. In Figure 8, therefore, NIC's 802, 803, 804, and 805, NetPort
806, File Server 807, Remote Management Agent (RMA) 808, and PC
809 all reside on segment 801. Devices which reside on different
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segments must be coupled by a router to communicate with each
other. NIC 811 belongs to segment 812; therefore, router 810 is coupled
between NIC 801 and NIC 811 in order for devices on segment 801 to
communicate with devices on segment 812.
During the discovery process, device interconnections may be
determined by examination of device attributes. For example, in one
embodiment devices may have their segment numbers and other
connection information encoded into their network addresses (which
are attributes). There may be more than one connection between two
nodes. In Figure 8, for example, the File Server 807 is connected to
NIC 803 two times; such a connection might appear when a server is
running more than one protocol stack (e.g., IPX and either TCP/IP or
AppleTalk). Also, by the property of transitivity, if there is a path
between two nodes, those nodes are connected and the intervening
nodes can be ignored by an application, if appropriate.
Referring again to Figure 6, the PNM Manager 331 is essentially
a front-end for the database. The PNM Manager 331 is responsible for
properly maintaining all links and performing the queries requested
of it and ensures that new nodes are inserted properly into the graph.
The PNM Manager 331 can use the transitivity of the database to build
lists of connected objects (e.g., which computers are connected to a
particular segment).
As mentioned above, the physical network database 333 is
characterized by a schema. Figure 7 is an ORM diagram conceptually
illustrating the PNM schema. The PNM schema is based on the
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metashema described above with reference to Figure 5. The schema
includes several object types for defining records in the physical model
database 333. Referring to Figure 7, the object types include: device
701, group 702, task 703, category 704, and bitmap 705. The device
object type 601 is used to represent the devices in the network, and the
group object type 702 is for representing groups of devices. The task
object type 703 is for representing the tasks which may be performed,
and the category object type 704 is for representing categories of tasks.
The bitmap object type 705 is for representing displayable bitmaps of
devices, groups, tasks, and categories.
As illustrated by Figure 7, various device types 706 can be
defined by the user. Each device type 706 can have multiple devices
701 associated with it; however, each device 701 can be of only one
device type 706. Each device 701 can have one or more tasks 703
associated with it, and a task may be performable upon (or by) more
than one device. If a device has a task, then that task is performable
taking the device as a parameter. Each group 702 can have both
devices 701 and tasks 703 as members. If a task is a member of a
particular group, then that task may take as a parameter any device
which is a member of that group. A group 702 can be a specialization
of a device type 706 (i.e., a group can represent a particular type of
device). A device 701 can be a member of more than one group 702.
Groups 702 can be defined by the user based on arbitrary criteria and
can be overlapping. Each category 704 has at least one task 703 as a
member. As with groups, categories 704 can also be defined by the
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user and can be arbitrary. Devices are represented by two bitmaps 705,
an active bitmap to indicate that the device is on-line, and an inactive
bitmap to indicate that the device is off-line. Each task 703 and each
category 704 is also represented by a bitmap 705.
D. View Generator
The view generator 304 provides a user-definable listing of
devices in the network 10 and available tasks, which may be displayed
in the device window 201 and the task window 202 (see Figure 2A).
The LAN Administrator can arrange devices in different ways to
provide the most useful presentation of network organization. In
particular, the user interface provide capability for "drag-and-drop"
maintenance of groups, group membership, and devices. A facility to
expand and collapse portions of the device tree is also provided. The
view generator 304 also provides capability to: show both historical or
real-time information about the devices on the network; show group
membership; filter the devices and groups to select only certain
devices or groups for display; and, expand and collapse the displayed
portions of the tree structure of devices/groups or tasks/categories.
In one embodiment of the present invention, illustrated in
Figure 9, the view generator 304 provides for two views to be
displayed in tree-hierarchy form, a logical group view and a task view.
In this embodiment, the view generator 304 includes a logical group
view generator 341, a task view generator 342, an object filter module
344, and a view generator API 346 driving the group view generator
34I, and the task view generator 342. The view generator 304 includes
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API functions related to the generation of tree views and is logically
coupled to a tree generator 345. Various other view generators 343
may also be included for generating different types of displays.
The view generator API 346 allows a client application to
request that a logical view be displayed, and which type of view is to be
displayed. Means is also provided for the maintenance of groups,
group membership, and devices. The client application is notified of
changes in the selection state, and can query the current selection state.
The client application can search for a device in the list by name,
group membership, or both. The search can be repeated to find
multiple occurrences of a device in the tree. Client applications can
also specify a filter to select only certain devices or groups be displayed.
The logical group view generator 341 populates the tree
structure for display in the device window 201 of the logical view 200.
A logical group is simply a collection of devices. The logical group
view generator 341 fills an outline for display within the device
window 201 with a list of devices grouped according to their group
memberships. The group view generator 341 obtains group
definitions from the physical model database 333, while device
information is obtained from the discovery manager 301. This
information may be real time, historical, or both, depending on the
type of display requested by the client. The devices and groups are
then filtered according to user-provided criteria, leaving only those
devices and groups requested. The remaining information is then
placed in the outline for display. The tree generator 345 generates the
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graphics functions required to display the outline in the form of a tree
hierarchy. Various methods and products are known in the art for
performing the function of the tree generator 345.
In the device window 20I, a top level of the tree-structure will
contain a line for each defined group. Expanding a line (e.g., by
double-clicking with the mouse) will reveal, at the next level, the
individual members of the group. Note that a device may belong to
more than one group. Two classes of logical groups are provided for:
1) device types, 2) and user-created groups. Device types are
predefined logical groups that correspond to physical device types.
The discovery modules 312 can automatically create these groups and
assign group membership. User-created groups are created by the
LAN administrator who assigns group membership.
The Task View Generator 342 populates the tree-structure for
display in the task window 202 of the logical view 200. In the
preferred embodiment, all tasks that can be performed on a selected
device in the device window 201 are displayed in the task window 202.
The top level of the outline contains the task categories of a selected
device or group. Expanding a category will reveal, at the next level,
the actual tasks that are available. Users may create task categories and
tasks within any predefined or user-defined category. In one
embodiment, if the current selection is a device, the displayed
available tasks are both those tasks that are directly assigned to the
selected device and all tasks that are assigned to all groups of which
the device is a member. If the current selection is a group, the
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displayed available tasks are those tasks that are assigned directly to
the selected group. Further, if multiple items are selected, the
displayed available tasks are the intersection of all tasks that are
assigned directly to all selected devices, all tasks that are assigned
directly to all selected groups, and all tasks that are assigned to all
groups of which the selected devices are members. As with the group
views, the tree generator 345 generates the graphics functions required
to display the tasks and categories in the form of a tree hierarchy.
The other view generators 343 may be included to generate
other alternative views of the network. Alternative views might
include a schematic display of segments, such as that shown in Figure
8, or a geographic layout of network components. A geographic view,
for example, may be implemented by combining discovered device
information with grid coordinates corresponding to a floor plan of a
particular building or complex.
The Object Filter Module 344 is used to reduce the logical view
data down to only that information which the client application
wishes to display, as mentioned above. For each group and device
displayed, that device will be compared to the criteria of the filter and
displayed only if there is a match.
The core services 300 also include a logical view database which
provides storage and retrieval of information about groups, such as
group names, the bitmap to be displayed when a given group is
displayed, and members of the group. In the preferred embodiment,
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the logical view database is included in the physical model database
333 for data consistency.
E. Task Manager
The task manager 305 performs two main functions:
1) maintaining knowledge of all executable tasks in the network and
the devices upon which such tasks can be operated, and 2) initiating
tasks in response to user commands entered via the control panel. A
task consists essentially of an atomic script and any associated
parameters. A parameter associated with a task may be a device upon
which a task will be performed. Tasks include functions for
troubleshooting, monitoring, and reporting on devices.
In determining the executable tasks in the network and the
devices on which such tasks can be performed, the task manager 305
makes use of the PNM schema described with reference to Figure 7.
Recall that each device can have one or more tasks associated with it;
that if a device has a task, then that task is performable taking that
device as a parameter; that each group can have both devices and tasks
as members; and, that if a task is a member of a particular group, then
that task may take as a parameter any device which is a member of the
same group. Thus, tasks are linked to devices and groups of devices.
The task manager 305 examines these links to determine the available
tasks for particular devices and groups. In the preferred embodiment,
available tasks are stored in the physical model database 333.
As will be discussed below, the task manager 305 can provide a
display, in response to a user's selection of one or more devices or
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groups, showing the effective tasks associated with the selected devices
or groups . A user may initiate a task by, for example, selecting a
device or group and then double-clicking on an available (displayed)
task. Tasks may also be defined by the user, and individual tasks may
be combined by the user to form compound tasks.
The function of maintaining knowledge of all executable tasks
in the network can be broken down into four sub-functions: 1)
calculating tasks for a device or group which has been selected via a
user input; 2) calculating tasks for a group; 3) calculating tasks for a
device; and, 4) calculating tasks of a component (device). With regard
to the first sub-function, a user input selecting one or more devices or
groups will cause the Task Manager 305 to invoke an API call to the
link in the physical model database 333 that associates the selected
devices or groups with their effective tasks. Figure 12 illustrates the
steps for calculating the tasks for a selection (device or group). The
value Effective Tasks, which is initially null (step 1201), represents all
effective tasks for the selected device or group. For each group that is
selected (step 1204), the effective tasks for the group, Tasks for Group,
is calculated (step 1202), and Effective Tasks is then updated to be the
intersection of Effective Tasks with Tasks for Group (step 1203). Next,
for each device that is selected (step 1207), the effective tasks for the
device, Tasks for Device, is calculated (step 1205), and Effective Tasks is
updated to be the intersection of Effective Tasks with Tasks for Device
(step 1206). The value Effective Tasks is then returned (step 1208).
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Figure 13 illustrates the steps for calculating tasks for a group.
The value Tasks for Group, which is initially null (step 1301),
represents all effective tasks for a given group. Tasks for Group is
unioned with the effective tasks (Tasks for Group) for a "current
group" to generate a new value of Tasks for Group (step 1302). Next,
the current group is updated to be the parent of the current group (step
1303), and the previous step (step 1302) is repeated until the current
group is the root (top level of the tree) (step 1304). The value Tasks for
Group is then returned (step 1305).
Figure 14 illustrates the steps for calculating the tasks for a
given device. The value Tasks for Device, which is initially null (step
1401), represents all effective tasks for a given device. For each group
of which the device is a member (steps 1402, 1405), the effective tasks
for that group, Tasks for Group, is calculated (step 1403), and then
Tasks for Device is updated to be Tasks for Device unioned with Tasks
for Group (step 1404). Next, the effective tasks for all components of
the selected device, Component Tasks, is calculated (step 1406). Tasks
for Device is then updated to be Tasks for Device unioned with
Component Tasks (step 1407). Next, Tasks for Device is updated to be
Tasks for Device unioned with all tasks which are assigned to the
given device (step 1408). Finally, the value Tasks for Device is
returned (step 1409).
Figure 15 illustrates the steps for calculating Component Tasks.
The value Tasks for Component, which is initially null (step 150I),
represents all effective tasks for a component of a given device. For
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each device which is a component of a given device (steps 1502, 1505),
Tasks for Device is calculated (step 1503), and Tasks for Component is
updated to be Tasks for Component unioned with Tasks for Device
(step 1504). The value Tasks for Component is then returned (step
1506).
Thus, a method and apparatus for providing management
services for a computer network has been described. The
management services are designed from a flexible, device-oriented
perspective in order to provide the user with information on the
layout of the network, tasks that can be performed, and the devices on
which each particular task can be performed. The services further
provide the user with customizable ways of viewing the layout of the
network. Although the present invention has been described with
reference to specific exemplary embodiments, it will be evident that
various modifications and changes may be made to these
embodiments without departing from the broader spirit and scope of
the invention as set forth in the claims. Accordingly, the specification
and drawings are to be regarded in an illustrative rather than a
restrictive sense.
