This document covers the following topics:
See also Natural Buffer Pool which provides general information on the buffer pool and explains how to start the buffer pool.
Warning: This utility should not be generally accessible to all users of Natural, because its use can cause damage to the work of other users of the buffer pool. |
You can invoke the NATBPMON
utility either for the
default buffer pool NATBP
or for another existing buffer pool.
To invoke the NATBPMON
utility
If the default buffer pool NATBP
is to be used,
enter the following command in the command line:
NATBPMON
Or:
If another buffer pool is to be used, enter the following
command in the command line:
NATBPMON BP=buffer-pool-name
The following prompt appears:
NATBPMON>
If you want the NATBPMON
utility to terminate with an appropriate
error message, add GIVERC
to your command in the
command
line.
The following commands can be entered at the NATBPMON
prompt:
Command | Description |
---|---|
CLEAR |
This is the same as the
ZERO command.
|
CORPSES |
Displays the list of corpses. A corpse
is an object that has been deleted, but was still being used in the buffer pool
when its deletion took place. Once this object is no longer used, it will
automatically disappear from the list of corpses.
Note: |
DELETE
{pattern|[*]} |
Deletes an object from the buffer pool. All objects can be deleted from the buffer pool by using an asterisk (*). A pattern is used to specify a collection of objects, similar to current operating systems which allow the specification of a class of files with wildcards. For further information, see Specifying a Pattern. |
DIR
{pattern|[*]} |
Displays a directory containing all objects in the buffer pool. For further information, see the sections Specifying a Pattern and Displaying the Objects in the Buffer Pool. |
DUMP |
Used for error analysis.
Important: |
EXIT |
Exits the NATBPMON
utility.
|
FIN |
Exits the NATBPMON
utility. This is the same as the EXIT command.
|
HELP |
Displays a list of all available
commands of the NATBPMON utility.
|
IPCRM |
Frees the resources allocated to the
buffer pool. This command should only be used following a
SHUTDOWN command when there are no active users.
|
KILL
n |
Kills the specified buffer pool user.
n is the number of the user to be
"killed". This number corresponds to the index number as displayed
by the WHO command.
|
PARAM |
Displays the buffer pool settings. For further information, see Displaying the Buffer Pool Settings. |
QUIT |
Exits the NATBPMON
utility. This is the same as the EXIT
command.
|
SHUTDOWN [FORCE
[grace-period]] |
Without the option
FORCE : Shuts down the buffer pool. No new processes will
be able to use the buffer pool once this command has been issued. The
NATBPMON utility is able to run with a buffer pool which has the
shutdown status "pending"; all commands of the
NATBPMON utility are available in this case. As
soon as all users have stopped using the buffer pool, the buffer pool's
resources can be deleted with the IPCRM
command.
The option Note: |
STATUS |
Displays statistical information about the buffer pool. For further information, see Statistical Information About the Buffer Pool. |
SWAP |
Only available for a read-only buffer pool. Tags a read-only buffer pool as "obsolete". All Natural sessions attached to such a buffer pool will detach from that buffer pool and attach to the alternate buffer pool. |
WHO |
Displays a list of all users who are
using the buffer pool. The following statistics are displayed: a number that
the NATBPMON utility automatically assigns to each buffer pool
user (index) and the user ID, terminal ID and process ID of the process using
the buffer pool (tid).
|
WRITE |
Writes a buffer pool object onto the
disk. You are prompted to specify an index and a file name.
Note: |
ZERO |
Resets to 0 all counters that are
displayed by the STATUS command.
|
The DIR
command displays a list of
objects. This list contains the following information:
Column | Explanation | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
indx | A number that the NATBPMON utility
automatically assigns to an object when it is loaded into the buffer
pool.
|
||||||||||||||
cusr | The current number of users that are using an object in the buffer pool. | ||||||||||||||
pusr | The peak number of concurrent activations of an object in the buffer pool. | ||||||||||||||
nusg | The number of times an object has been activated in the buffer pool. | ||||||||||||||
g |
|
||||||||||||||
size | Specifies the size (in bytes) of an object in the buffer pool. | ||||||||||||||
gpv | The version number of the generated program. | ||||||||||||||
key |
|
When the DIR
command is issued, all
objects in the pool will be displayed in a notation similar to the
following:
indx: index of the element cusr: current number of concurrent users pusr: peak number of concurrent users nusg: number of usages g : set if object is generating gpv : version of generated program indx | cusr | pusr | nusg | g | size | gpv | key -----+------+------+--------+-----+--------+-------+--------------------------------------------------- 1 | 0 | 1 | 4 | 0 | 920 | | (D=99 F=101 L="DEMO" N="SEL-MAP" K='G' T='M') 2 | 1 | 7 | 2 | 0 | 3096 | | (D=99 F=101 L="DEMO" N="EMWND" K='G' T='P') 3 | 4 | 9 | 4 | 0 | 604 | | (D=99 F=101 L="DEMO" N="HDR" K='G' T='P') 4 | 2 | 3 | 7 | 0 | 412 | | (D=99 F=101 L="RPA" N="MMUPROG1" K='G' T='P') 5 | 0 | 1 | 5 | 0 | 372 | | (D=99 F=101 L="RPA" N="MMUPROG2" K='G' T='P') 6 | 0 | 5 | 4 | 0 | 372 | | (D=99 F=101 L="RPA" N="MMUPROG3" K='G' T='P') |
A pattern can be specified with the commands
DIR
and DELETE
. The
examples in this section apply to the DIR
command.
To select some objects, it is possible to restrict the values of certain key fields by specifying a matching pattern expression.
To restrict the allowed field values of a given field, the following pattern notation must be used:
name=expression
You can specify multiple patterns by separating them with a comma.
The specified patterns must all match their corresponding fields in order to accept the entire key.
The expression accepts the specification of the wildcard characters "*" and "?".
The character "*" matches any or no occurrences of a sequence of characters, and the wildcard character "?" matches exactly one specific character.
To select all objects of type P
in the sample above,
the following command would be used:
DIR T=P
To select all programs in the demo library, the following command would be used:
DIR T=P, L=DEMO
To select all objects containing an M
in their name,
the following command would be used:
DIR N=*M*
The following settings are displayed with the
PARAM
command:
SHM active since ..........: 13-JUL-2021 9:22:36, Version 9.1(914F00) Last time cleared .........: 13-JUL-2021 9:22:36 Bpid ......................: NATBP Readonly ..................: no Shmkey ....................: Global\NAT91BPMEM_0x19141111004 Semkey ....................: Global\NAT91BPMEM_0x19141111004 Memsize ...................: 104857600 Maxusers ..................: 20 |
Bpid | Buffer pool ID. |
Readonly | Indicates whether this is a special buffer pool which only allows read access. |
Shmkey | Unique name used to create a buffer pool or to connect to a buffer pool. |
Semkey | Unique name used to synchronize accesses to the buffer pool memory. |
Memsize | Size of the available shared memory. |
Maxusers | Maximum number of users that can have simultaneous access to the buffer pool. |
See Buffer Pool Assignments in the Configuration Utility documentation.
The following statistics are displayed with the
STATUS
command:
Bufferpool version 9.1(914F00) of 07/9/2021 NATBPMON>st SHM active since .......: 13-JUL-2021 9:22:36, Version 9.1(914F00) Last time cleared ......: 13-JUL-2021 9:22:36 Bpid ...................: NATBP Allocated memory (b) ...: 647620 Max users ............: 20 Smallest allocation ....: 20 Current users ........: 1 Largest allocation .....: 62412 Peak users ...........: 2 Free memory (b) ........: 104209992 Dead users purged ....: 0 Smallest free ..........: 5628 Largest free ...........: 103929708 Dormant objects ........: 98 Smallest object (b) ..: 108 Active objects ........: 0 Largest object (b) ...: 31228 Generating objects .....: 0 Total object sizes ...: 578083 Obsolete objects .......: 0 Attempted locates ......: 314 Stored objects .......: 0 Attempted fast locates .: 124 Loaded objects .......: 100 Successful fast locates.: 106 Activated objects ....: 295 Percent ................: 85,48 Aborted loads ........: 2 Dormant objects purged .: 0 Peak parallel activations: 1 Object reusage factor ..: 2,95 |
General Information | |
---|---|
Bufferpool version | Version of the buffer pool including
its fix level (enclosed in brackets as
vrsFnn ,
where vrs is the buffer pool version
and nn is its fix level).
|
SHM active since | Date and time when the buffer pool was started, the version number, and fix level of the program which started the buffer pool and allocated the shared memory. |
Last time cleared | Date and time when the buffer pool was most recently cleared. |
Bpid | Buffer pool ID. If applicable, the read-only and swap status is shown enclosed in brackets. |
Memory Allocation | |
Allocated memory (bytes) | Total of all allocated memory. |
Smallest allocation | Smallest amount of allocated memory. |
Largest allocation | Largest amount of allocated memory. |
Free memory (bytes) | Total of all free memory. |
Smallest free | Smallest amount of contiguous free memory. |
Largest free | Largest amount of contiguous free memory. |
User Statistics | |
Max users | Maximum number of users that can have simultaneous access to the buffer pool. See Buffer Pool Assignments in the Configuration Utility documentation. |
Current users | Number of users currently using the buffer pool. |
Peak users | Peak number of users that have been using the buffer pool. |
Dead users purged | Number of inactive users that have been deleted from the buffer pool. This number should be close to 0 (zero). An increment of this number indicates that entries for buffer pool users (i.e. Natural sessions) were canceled or killed unconditionally. Each time an entry for such a user is identified by the buffer pool manager, this number is incremented and cleanup is performed to remove residuals which have been left in the buffer pool by a canceled session. |
Object Use Statistics | |
Dormant objects | Number of available, but inactive objects. These objects are in the buffer pool, but are not being used. They are available for later use and will become active objects as soon as a buffer pool user requests their availability. |
Active objects | Number of active objects. These objects are currently in use by one or more buffer pool users. |
Generating objects | Number of objects that are currently being loaded into the buffer pool. These objects will become available as soon as the load operation completes. |
Obsolete objects | Number of objects that are to be deleted from the
buffer pool, but are still being used. These objects can be displayed by using
the CORPSES command. An obsolete object is removed
from the buffer pool as soon as all users who activated this object have
released this object. In a production environment, this number should be 0
(zero). A value other than zero indicates that objects were deleted either
using the DELETE command of NATBPMON or
became obsolete because new objects were created (for example, due to a
CATALOG command).
|
Object Size Statistics | |
Smallest object (bytes) | Size of smallest object in the buffer pool. |
Largest object (bytes) | Size of largest object in the buffer pool. |
Total object sizes | Total size of all objects in the buffer pool. |
Locate Statistics | |
Attempted locates | Number of successful and failed object locates. This number tells you how many times the buffer pool manager was asked to locate an object in the buffer pool. |
Attempted fast locates | Number of attempted activations with known slot. This is the number of object activations when the former location of an object was known. It is highly probable that an object can be found in the same place in the buffer pool when it is reactivated. |
Successful fast locates | Number of successful fast locates. |
Percent | Percentage of successful fast locates. |
Object Loading Statistics | |
Stored objects | The number of objects stored in the buffer pool. This is the number of objects that were stored into the buffer pool and which were not loaded from the system file. |
Loaded objects | The number of objects loaded from the system file. Each time an object is not found in the buffer pool, it is loaded from the system file. This number is increased each time an object is successfully loaded into the buffer pool. |
Activated objects | The number of activated objects. Activation is the process of marking an object which is found in the buffer pool as "in use" by a buffer pool user. |
Aborted loads | The number of load operations that were aborted due to memory shortages within the buffer pool, or due to an error when loading an object into the buffer pool. This number should not vary in a noticeable way. |
General Loading Statistics | |
Dormant objects purged | The number of unused objects deleted from the buffer pool to make room for newly loaded ones. |
Peak parallel activations | The maximum number of parallel activations of one of the objects in the buffer pool. |
Object reusage factor | Average number of times an object was reactivated. This number is the ratio of the number of object activations to the number of objects loaded into the buffer pool. |