 |
Description  |
|
|
TECHNICAL FIELD
This invention is in the field of local area network (LAN) controllers and
is more particularly directed toward notifying users and programs on the
network of an event occurring on the network.
BACKGROUND OF THE INVENTION
LANs which provide a single, central file server for a plurality of users
are well known in the art. According to the prior art, a central file
server controls a plurality of devices and is controlled by a plurality of
users according to many different programs. The central file server must
run programs for controlling the print queue, loading data into the print
queue, writing data to one or more disks, reading data from one or more
disks, writing data to screens of individual users, and many other
functions.
The central file server controls programs as directed by one or more users.
While one user is running a particular program, another user may desire
information about the program or devices controlled by the program. For
example, while one user is printing a job, another user may desire to know
the status of the printer and of any jobs in the print queue. Using the
prior art, when a user desires to know the status of another program, such
as a print controller, or of a device, such as a printer, the user is
required to address the program or device and poll it for information. The
device is then required to provide the information to the requesting user.
If the status of the printer or print queue changes a moment later, the
user desiring to know the status is not notified Rather, the user is
required to poll the printer or printer queue again to determine current
status. If a user desires to know information about any other program or
device, he is required to individually poll the selected device.
Frequently, the user is required to know the individual address,
particular protocol, and data formatting scheme for the device and program
to which the inquiry is directed.
A significant disadvantage of the prior art is that all requests about
network status, program operation, and device information are user driven.
Each user desiring information is required to generate the signals
requesting information. The programs providing information are required to
interrupt their processing to provide the requested information to the
user on demand. For a complex network, a user may be required to recall
many different codes and protocols for addressing numerous individual
devices and programs within the network. The result is that many users are
unaware of the status of numerous devices and programs operating on the
network. User confusion and frustration result from the lack of
information. The network is slowed down if many users communicate with a
program while it is running.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a method of
automatically alerting users and programs about logical events occurring
while programs are running on a network.
It is another object of this invention to provide an apparatus for
monitoring logical events on a network and notifying programs desiring
information on specified types of events.
These, and other objects of the invention, are accomplished by providing an
alert function call and an alert database on the network. Upon occurrence
of a logical event in an operating program or device, an alert function
call is called by the respective program. The alert function call creates
a buffer from the memory allocated for the operating program. Data
describing the event are formatted and stored in the created buffer as an
alert report. The source program notifies an alert database that a logical
event has occurred and that an alert report describing the event is stored
in a particular buffer. The alert database contains a look-up table of the
addresses of all programs desiring to receive events, specified by event
type. The alert software steps through the look-up table and writes a copy
of the requested alert report data to all requesting programs. After the
alert database has stepped through the look-up table, the operating
program disassembles the buffer and continues its operation.
The receiving programs take action upon receiving an alert report. For
example, one receiving program may notify the user that his own print job
is completed. Another receiving program may notify a particular user or
administrator as every print job is completed. The receiving program may
also take action based on the event. For example, the receiving program
may automatically control ordering paper and may place an order for
additional paper based on the number of pages printed over a specified
period. The receiving program may automatically store program data in a
memory in anticipation of the event causing the network to go down.
An advantage of the invention is that each source program of a logical
event merely performs a function call to alert all users of the occurrence
of the event. After sending the event data to specified address, a rapid
operation, the operating program continues operation. Interaction with
another program is not required. Any user desiring to be notified of a
logical event on the network merely provides the event types of which he
wishes notification to the alert database and the address to which he
wishes the data sent. Once received at the address, the user decides what
to do with the data. The user may select to store the data in memory,
print it to the screen, produce a report, log in event occurrences over
time, or the like.
A further advantage of the invention is that the event triggering the
notification in the operating program is software defined. If users of the
system determine, after several months of operation, that occurrence of an
event is important, a function call to the alert database for execution
upon the occurrence of the event is inserted into the operating program
responsible for producing the event. The new event type is defined, both
for the operating program and the user. Any user desiring to receive this
event type provides a receiving address to the alert database. Similarly,
each user defines the action to be taken when data is received and can
modify the action as desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a logical event notification flow from an
operating program, through the alert database to a receiving program.
FIG. 2 is a description of the flow of a single logical event from a
spooler program to a receiving program.
FIG. 3 is a flow chart of the alert database a logical event function call.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the general data flow from an operating program, through
the alert database to a receiving program. An operating program 10, 12, or
14 on the network performs functions for controlling devices or is
controlled by devices or the network. The operating program is the source
of the event; it may be referred to as the source program. As programs
operate on the network, logical events occur. When the occurring event is
one that is important to the users, a function call to the alert database
16 immediately occurs after the event, as the next step in the operating
program. The function call has been previously inserted by users or a
system administrator. The operating program performs the alert database
function call. Control is not transferred to a different program; rather,
the operating program that is the source of the event retains control of
the computer processor.
The alert database function call transfers a notification of the event to
all programs requesting notification of such an event. The alert database
16 includes a look-up table listing of event types. For each event type,
an address is provided for receiving the notification. The type of
notification requested is also listed. Some programs request only a
summary of the event; others request a detailed report. The type of
notification requested is sent to the addresses listed in the look-up
table.
The addresses in the look-up table are entry points into receiving programs
18, 20 and 21. The receiving programs 18, 20 and 21 contain instructions
for performing functions based upon the event data. If the receiving
program is a user notification program 18, users are notified of the event
in the manner they request. Some users receive a mail message in their
mailbox describing the event. For other users, the event description is
printed. For still other users, the event description is printed on the
screen immediately. The type of notification received by each user is
controlled by the user. If a user desires to change the type of
notification he receives, he may easily modify the notification scheme.
However, the type of notification provided to the user does not alter the
operating program, the function call or alert database. Decoding the event
description and notification to the user are selected by the individual
user.
Other programs 20 and 21 receive notification of the event. A system
administrator receives reports for system program 20 of numerous event
types, providing him with the status of the operation of the system. Other
receiving programs 21 may store the event or take action based on the
event type
FIG. 2 illustrates the flow of one particular type of a logical
notification event as an example. While the logical event illustrated is a
print job error, such as a print jam, any logical event follows the same
sequence. A spooler program, while operating a printer, notices a print
jam in a particular printer. A print jam has previously been selected as a
logical event requiring notification. The spooler program becomes the
source program for that particular event and executes the alert database
function call. The spooler program formats a description of the event into
an alert report. The alert report lists the event type, a printer event;
the time of the event; the source of the event, the spooler program; and
information describing the printer event as a paper jam on a particular
printer. The alert report is stored in a buffer created by the spooler
program. The spooler program notifies the alert database via the Net Alert
Raise Application Program Interface ("API") function call.
The function call of the alert database steps through a look-up table of
addresses requesting notification events by event types. All addresses
that have requested to receive printer events are sent data describing the
event. A full copy of the alert report is sent or, alternatively, a
summary of the data in the alert report is sent. The copy is sent to the
mail slot of an alerter program 18 or the mail slot of an Excel.TM.
program 21. To increase the speed of operation, the look-up table may be
presorted by global event type. The function may quickly enter the event
type address array and need not check each address. Upon sending a copy of
the alert report in the buffer to the requested addresses, the function
call ends and returns to the next step in the spooler program. The spooler
program continues operation.
The receiving program receives the alert report at the address provided to
the alert database. The receiving program decodes the event type as a
print event. The receiving program further decodes the event as a printer
error. If the receiving program has requested detailed information of all
printer errors, the receiving program continues to decode the message to
determine the type of printer error (printer jam, in this example), the
specific printer experiencing the error, and the queue to which the
printer is attached. Most users, not desiring detailed information on all
printer alerts, may receive nothing or receive only a summary of the alert
report, that a printer error has occurred, and not receive the rest of the
signal. Alternatively, a user may receive the full alert report, decode
the user, and then decode the rest only if he is the user. Generally, a
user will desire to have all print jobs for which he is listed as the user
fully decoded and displayed immediately on the screen. The program for the
individual user therefore notifies the user who owns the print job that a
paper jam has occurred. The administrator is also notified of the paper
jam so that appropriate action may be taken.
In one embodiment, an alert signal is sent to the alert database to provide
the notification that a logical event has occurred and that an alert
report is stored in a buffer. The alert signal includes a pointer to the
buffer storing the alert report. The alert database then copies the alert
report from the address of the pointer to the addresses requesting the
alert report. Sending an alert signal having a pointer differs from the
embodiment performing the function call to the alert database. In the
function call embodiment, the operating program steps through the look-up
table and copies and sends the alert report as steps in the function call,
but in the alert signal embodiment the alert database software copies and
sends the alert report. Either embodiment may be used to carry out the
invention and portions of either may be intermixed into a new embodiment
if desired.
Any program operating on the network may become a source program. For
example, in one embodiment, a backup battery is provided to power the
network for a specified period of time, such as for 20 minutes, in the
event power is lost. A power watch program monitors the status of power
input to the network. If power is interrupted to the network, the power
watch program notices the logical event, power failure, creates an alert
report and stores the report in a buffer it allocates. The power watch
program is the source program. The source program notifies the alert
database of the alert report. The alert database steps through the look-up
table and sends the alert report to all requesters desiring information of
that type of event, a power failure. Generally, all users will request to
receive information of a power failure. The users are notified that the
system is operating on backup battery power and that a limited time
remains for them to complete their current tasks. A computer shutdown
program 21 will also receive the alert report. When the shutdown program
21 receives an alert report that there is a power failure, the shutdown
program begins to take action based on the event. The shutdown program
begins to close files which are open, move data from volatile RAM memory
to disk storage, and perform other functions necessary to provide smooth
shutdown of the system. The program prepares the network to retain all
programs and data intact upon depletion of the battery power.
In one embodiment of the invention, the system administrator is
automatically alerted whenever the quantity of data on the disk exceeds a
threshold amount. The administrator may then take action to conserve disk
space or delete programs. The program may automatically delete the oldest
versions of some programs to obtain more disk space. The program may send
mail to users using significant disk space and ask them to clean-up .
their databases and remove unnecessary data.
A significant advantage of the present system is that the event types and
source programs do not need to be built into the system. The logical
events are selectable by software code. New programs can be added at any
time to define new events or control additional functions. If a user
desires to receive notification of an event, he does so by providing an
address to the alert database look-up table for the event type he is
interested in receiving. The alert database steps through the look-up
table looking for requesting addresses by event type. If a user does not
wish to receive an alert report for certain types of data, he does not
provide an address for that particular event type. As new event types are
created by the system administrator, a user may elect to receive alert
reports of that event type. The receiving program turns the alert report
into usable reader messages and sends copies to the user.
An advantage in speed and simplicity of operation is that the source
program and receiving program are not connected to each other during the
alert database function call. Rather, the operating program that raised
the event also created the alert report and sent the alert report to
addresses based on a look-up table. Upon sending the program to the
requested addresses in the look-up table, the source program's job is
completed and it returns to the task at hand.
Notification of all events for all users goes through the alert function
call, significantly simplifying notification for many types of events. A
separate, customized user notification scheme for each device is not
required The alert report need only be sent to the "Grand Central Station"
of the alert database 16 and then it is appropriately rerouted from there
based on addresses listed in the look-up table. For example, one address
to which the alert report may be sent from the alert database is an
Excel.TM. database. The Excel.TM. database may change a printing graphics
signal ("icon") to a printing error icon to notify the user of the printer
error. The operating program is not concerned with which or how many
programs receive the alert report. The receiving program need only send
the request for an alert report into the single, Grand Central Station and
it receives a copy as it is rerouted as directed there.
Sending a data string to a listed address in memory is a rapid, yet simple
process. No computation, polling or interruption of another process is
involved The data is sent, one-way, and the job is completed. The computer
time required is significantly less than if a user were to poll the
program to ask for a status report of an event. If many users are asking
for event data, the network slows down and network operation becomes
complex. If, as the invention teaches, users receive notification of
events as they occur, smooth and efficient operation results. The user
need only set up an address to receive each type of event of interest to
him and, as the event occurs, he is notified.
FIG. 3 is a detailed flow chart of the source program performing the
function call to send an alert report. As the program operates, a logical
event occurs, 24. Upon the occurrence of a logical event, the alert
database function call is entered. The source program creates a buffer 26
from the memory space allocated for its own operation. The source program
then stores event data in the created buffer and formats it as an alert
report 28. The source program notifies the database of the buffer 29. The
database steps through the look-up table searching for requests for this
event type. A copy is sent to all addresses requesting data of the event
type received 30. After the report has been sent to all addresses
requesting this event type 31, the buffer is disassembled 32 and the
source program continues operation 34.
An alert report is formatted having the following data: "event type," "date
and time," "source of event," and "information." The "event type"
specifies the type of event which has occurred. Event types may include,
as a broad category, printer errors. Alternatively, the event type may
provide information of the type of printer error, such as "paper jam,"
"out of paper," "print queue full," or the like. Other event types include
system disk events, such as, "disk full," "disk approaching a threshold
full level," "disk error," "failure in reading disk," "failure to write
data to disk," or the like. Other event types include "user logged on,"
"power failure," "central controller error," "error writing to RAM," or
the like.
The "date and time" specifies the date and time of the occurrence of the
logical event. The "source of the event" specifies the operating program
that is the source program. The source program may be a printer control
program, a disk control program, or the like.
The "information" is detailed data provided of the event. The "information"
data within each alert report will be different, based on the event type.
For an event type of a printer error, the "information" will likely
include such features as the job ID, the status of the job, the size of
the job, the submission time, the user name, the queue name, the printer
destination, a status string containing specific information about the
print error, and the like. Alternatively, the "information" may include a
summary of the alert report and then provide an address where a more
complete report has been stored. The receiving program may direct that the
"information" be stored, addressed to a mail slot, printed, or the like.
A user may desire to receive only a summary version of an alert report. A
summary version of the alert report may include only the event type. The
event type is thus transferred to programs requesting the event type only,
while more detailed information is sent to programs requesting the
complete alert report. Generally, a user will desire to receive complete
information on all event types for which his name occurs as the user name.
His user program at the receiving address contains the directions to
examine the alert report to determine if it is of interest to him. The
source program is not concerned about each individual user's interest in
the data but merely sends the requested data to the listed address and
returns to work. The invention thus provides for fast notification to
users and then continued operation.
Frequently, a user or a program is not interested in receiving notification
of many event types, particularly the event types which do not concern
him. A user will therefore not provide an address in the look-up table for
event types which are of no interest to him. For example, a user not
desiring system information or the status of hard disk storage would not
provide a receiving address for alert reports of these event types.
Generally, the network administrator desires to receive notification of
each event type. The system administrator therefore provides an address
for each logical event which will occur during operation of the network.
The address provided for each event type may be different. The program
receiving each different event type decodes it and takes appropriate
action. The program therefore takes steps based on the event type
received.
While a specific embodiment of the invention has been described in this
application, any equivalent function or device operating according to the
principals of the invention fall within the scope thereof.
* * * * *
|
|
 |
|
 |
Description |
|
