# Compaq ACMS for OpenVMS
Managing Applications

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1. Parameters in use
   Displays the source of the values now in the work area. The CURRENT, ACTIVE, or DEFAULT keyword, or a file specification, can follow "Parameters in use". At the start of an ACMSGEN session, the keyword CURRENT follows "Parameters in use" because the work area contains current values by default. Each USE command changes the information following "Parameters in use".
2. Current
   Shows the values that are currently in the work area. Before you use a USE or SET command, the "Current" column contains current values. USE and SET commands change the values you see in the "Current" column.
3. Default
   Lists ACMS default values.
4. Minimum and Maximum
   Contain the limits for parameter values. A value of --1 means that a parameter has no maximum value.
5. Unit
   Displays the units of measure for each parameter value. "CP Threads" refers to Command Process threads. Each user has one Command Process thread. "Submitters" refers to ACMS users.
6. Dynamic
   Indicates whether a parameter is dynamic or fixed. A blank in the dynamic column means that a parameter is fixed.

To display values for parameters affecting the TSC, use the ACMSGEN SHOW/TSC command. Example 11-2 shows a sample display from this command.

Example 11-2 ACMSGEN SHOW/TSC Command

    ACMSGEN> USE ACTIVE
    ACMSGEN> SHOW/TSC

    Parameters in use: ACTIVE
    Parameter Name      Current  Default  Minimum  Maximum  Unit           Dynamic
    --------------      -------  -------  -------  -------  ----           -------
    MAX_LOGINS          20       60       0        -1       submitters     D
    MAX_TTS_CP           5       20       0        -1       terminals      D
    PERM_CPS            1        1        0        -1       command prcs   D
    CP_SLOTS            3        3        0        -1       command prcs
    MIN_CPIS            2        2        0        -1       CP threads     D
    TSC_USERNAME        SYSTEM   SYSTEM                     VMS username
    TSC_PRIORITY        6        4        0        31       VMS priority

The ACTIVE keyword after "Parameters in use" indicates that the last USE command was USE ACTIVE.

To display a value for one parameter, type SHOW followed by the name of the parameter. For example, the following SHOW command displays a value for the MAX_LOGINS parameter from the work file WORK.ACM in SYS$SYSTEM:

    ACMSGEN> USE WORK
    ACMSGEN> SHOW MAX_LOGINS

The USE command initializes the work area with values from the work file WORK.ACM. The SHOW command displays the value from the work file for the MAX_LOGINS parameter. The following is a sample display for the SHOW MAX_LOGINS command:

    ACMSGEN>SHOW MAX_LOGINS
    MAX_LOGINS          20       60       0        -1       submitters     D

When you display information for only one parameter, the display does not contain headers.

# 11.7 ACMS Parameters

This section lists the types of ACMS parameters and their value ranges, and provides a description of each ACMS parameter.

## 11.7.1 Types of ACMS Parameters

The six types of ACMS parameters are: ACC, CP, message switch, QTI, TSC, and workspace pool.

Table 11-2 lists the ACMS parameters according to parameter type and lists the commands you can use to display the parameters. See Section 11.7.2 for parameter descriptions.

Table 11-2 ACMS Parameters
Command | Parameter
--- | ---
ACMS Central Controller Parameters
SHOW/ACC | ACC_PRIORITY
| ACC_USERNAME
| MAX_APPL
| USERNAME_DEFAULT
Command Process Parameters
SHOW/CP | CP_PRIORITY
| CP_USERNAME
Message Switch Parameters
SHOW/MSS | MSS_MAXBUF
| MSS_MAXOBJ
| MSS_NET_RETRY_TIMER
| MSS_POOLSIZE
| MSS_PROCESS_POOL
| NODE_NAME
Queued Task Initiator Parameters
SHOW/QTI | QTI_POLLING_TIMER
| QTI_PRIORITY
| QTI_RETRY_TIMER
| QTI_SUB_TIMEOUT
| QTI_USERNAME
Terminal Subsystem Controller Parameters
SHOW/TSC | CP_SLOTS
| MAX_LOGINS
| MAX_TTS_CP
| MIN_CPIS
| PERM_CPS
| TSC_PRIORITY
| TSC_USERNAME
Workspace Pool Parameters
SHOW/EXC | TWS_POOLSIZE
| TWSC_POOLSIZE
| WS_POOLSIZE
| WSC_POOLSIZE

## 11.7.2 Parameter Descriptions

ACC_PRIORITY

Is the OpenVMS priority used by the ACMS Central Controller. ACC_PRIORITY overrides the SYSUAF default priority. Usually the ACMS default value for ACC_PRIORITY is adequate. Too high a priority can lock out other OpenVMS users. Too low a priority decreases ACMS performance.

ACC_USERNAME

Is the OpenVMS user name used by the ACMS Central Controller. The default user name is SYSTEM. See Chapter 10 for information about the privileges and quotas you assign to ACC_USERNAME.

CP_PRIORITY

Is the OpenVMS priority used by Command Processes. CP_PRIORITY overrides the SYSUAF default priority. Usually the ACMS default value for CP_PRIORITY is adequate. Too high a priority can lock out other OpenVMS users. Too low a priority decreases ACMS performance.

CP_SLOTS

Limits the number of Command Processes that can be active. Because each terminal must be assigned to a Command Process, too low a value limits the number of terminals an active ACMS system can handle. The value for the CP_SLOTS parameter can be high without decreasing performance.

CP_USERNAME

Is the OpenVMS user name used by Command Processes. The default user name is SYSTEM. The user name you assign must have read access to the file pointed to by the logical name ACMS$NOTICE. See Chapter 10 for information about the privileges and quotas you assign to CP_USERNAME. The CP user name must be authorized as an agent in the UDU authorization file.

MAX_APPL

Limits the number of applications that can be active at any time. When the number of started applications reaches MAX_APPL, any attempt to start an additional application fails. Too high a value allows too many applications to be started, which can decrease system performance. Too low a value unnecessarily restricts the number of applications you can start.

MAX_LOGINS

Limits the number of users who can sign in to ACMS. You can set MAX_LOGINS to 0 if you do not want anyone to sign in. Too high a value for MAX_LOGINS decreases performance by letting too many users sign in to ACMS. See Section A.5.1 for information about changing the value of this parameter.

MAX_TTS_CP

Limits the number of terminals ACMS can assign to a Command Process. ACMS assigns terminals to a Command Process until the number of terminals assigned reaches the MAX_TTS_CP value. Too low a value for MAX_TTS_CP minimizes the advantages of using Command Processes by decreasing the ratio of terminals to processes. Too high a value slows the system.

MIN_CPIS

Prevents delays at sign-in by starting command processes before users need them. ACMS can always assign at least the number of terminals set by the MIN_CPIS value to an active command process. If user's signing in decreases the number of possible assignments to less than the value of MIN_CPIS, ACMS starts another Command Process. If the value for the MIN_CPIS parameter is too low, there is a delay when a user signs in. Too high a value for the MIN_CPIS parameter decreases ACMS performance by increasing overhead.

MSS_MAXBUF

Specifies the maximum size of a message that can be sent without incurring the overhead associated with blocking the message. If MSS_MAXBUF is set at too high a level, there may never be enough memory to allocate to the message. In this case, the message could go into a resource wait state. However, if MSS_MAXBUF is set at too low a level, overhead associated with blocking messages is incurred. See Section A.5.3 for information about changing the value of MSS_MAXBUF.

MSS_MAXOBJ

Specifies the maximum number of message switch objects that can be created on a system at one time. The MSS_MAXOBJ parameter determines the size of the table set up in the message pool. If MSS_MAXOBJ is set at too high a level, this table uses more of the message switch global pool, whose size is affected by the MSS_POOLSIZE parameter. However, if MSS_MAXOBJ is set at too low a level, message switch created objects will fail and cause some ACMS operations to fail. In this case, the Software Event Log contains the message MSS$_OBJFULL_F_ object table full, indicating that MSS_MAXOBJ has been exceeded.

MSS_NET_RETRY_TIMER

Defines the number of seconds ACMS waits to retry creating a DECnet object when ACMS distributed processing is enabled. The range for this parameter is 1 to --1 seconds. The default is 10 seconds.

MSS_POOLSIZE

Is the maximum amount of memory that can be used to send messages. The MSS_POOLSIZE parameter sets up a global section backed by the page file. If the MSS_POOLSIZE parameter is set at too high a level, system parameters associated with global sections (gblsections and gblpages) and the page file for global sections (gblpagfil) must be increased. However, if the MSS_POOLSIZE is set at too low a level, messages may be put into a resource wait state or may fail.

MSS_PROCESS_POOL

Defines the size of the ACMS internal message switch process local pool. This pool is used for various data structures for each message switch object and for DECnet input buffers. The range for this parameter is from 1 to --1 pages (VAX) or 1 to --1 pagelets (Alpha). The default is 256 pages (VAX) or 256 pagelets (Alpha).

Note MSS_PROCESS_POOL is overridden by the value of logical name ACMS$MSS_PROCESS_POOLSIZE if that logical name is defined. This can be useful if you need a large process pool, such as for a large number of single-threaded SI agents.

NODE_NAME

Defines the DECnet node name for your ACMS system and enables distributed ACMS processing when defined. When you define NODE_NAME, ACMS allows distributed forms processing provided DECnet is started. By default, the NODE_NAME parameter is null, which disables distributed forms processing.

PERM_CPS

Sets the number of permanently active command processes. The PERM_CPS parameter ensures that some Command Processes are always available when ACMS is active. If the value for PERM_CPS is too low, ACMS can start several Command Processes while ACMS is active. Because the overhead from starting Command Processes is high, too low a value decreases ACMS performance. Too high a value wastes ACMS resources because some Command Processes go unused. See Section A.5.6 for information about changing the value of PERM_CPS.

QTI_POLLING_TIMER

Specifies how long the QTI waits to try to access a queued task when an RMS locking situation was previously encountered the last time the QTI accessed the queue.

QTI_PRIORITY

Defines the OpenVMS priority for the QTI process. A value that is too high locks out other OpenVMS users; a value that is too low can decrease ACMS performance.

QTI_RETRY_TIMER

Specifies how long the QTI waits before attempting to reinvoke a queued task whose previous invocation failed. For example, if the application is not started, then the QTI waits the specified number of seconds before reinvoking the queued task.

When a queued task element does not complete successfully and is to be retried later, the QTI process sets the queued task element on HOLD. These elements, which have been placed on hold by the QTI, have a state value of "HOLD (RETRY PENDING)" when displayed by the ACMSQUEMGR using the SHOW ELEMENT command.

When the number of seconds identified by the QTI_RETRY_TIMER parameter has elapsed, the QTI process resets the element to NOHOLD. Thus, the element becomes a candidate for the next dequeue operation on the queue by a task execution thread. Elements are dequeued by highest priority, and are first-in/first-out (FIFO) within priority.

The effective value of QTI_RETRY_TIMER can be slightly greater than the value you set for the QTI_RETRY_TIMER parameter. That is, the amount of time that the QTI waits before retrying a failed task may be slightly longer than you specify. For the QTI to reset the hold state of queued task elements that are to be retried, it periodically scans all the task queues that are started and inspects the queued task elements that are in the HOLD (RETRY PENDING) state. The frequency at which the QTI performs this scan is 1/10 the value of QTI_RETRY_TIMER, but no less than every second and no more than every 5 minutes. For example, if QTI_RETRY_TIMER is set for 1800 seconds (1/2 hour), then the QTI scans all started queues every 180 seconds (3 minutes). In this example, the actual effective value for QTI_RETRY_TIMER could be as long as 33 minutes even though the QTI_RETRY_TIMER value specified is 30 minutes.

QTI_SUB_TIMEOUT

Specifies the amount of time that an inactive submitter remains signed in to the system before being signed out. The QTI caches submitter sign-ins so that it is not necessary to sign in every time a task is submitted.

Because each submitter that is signed in to ACMS consumes memory resources in the QTI, the ACC, and the EXC processes, the QTI process uses a mechanism that enables it to bypass a submitter sign-in for each task. Specifically, when the QTI process dequeues a queued task element, it checks the user name of that element. If it is the first time the QTI process has dequeued an element with that user name, it signs the submitter in to ACMS. However, the QTI process does not sign out of ACMS as usual. Instead, the QTI process leaves the submitter signed in for a certain amount of time before signing it out. That way, if another queue element with the same user name is dequeued, that user name is already signed in.

Use the ACMSGEN parameter QTI_SUB_TIMEOUT to indicate how long a submitter can remain inactive before the QTI process signs that submitter out of ACMS. To determine how many submitters are signed in under a QTI process, use the ACMS/SHOW QTI command.

QTI_USERNAME

Defines the OpenVMS user name for the queuing process. See Chapter 10 for information about the privileges and quotas you assign to QTI_USERNAME. The QTI user name must be authorized as an agent in the UDU authorization file.

TSC_PRIORITY

Specifies the OpenVMS priority used by the TSC. TSC_PRIORITY overrides the SYSUAF default priority. Usually the ACMS default value for TSC_PRIORITY is adequate. Too high a value for TSC_PRIORITY can lock out other users. Too low a value decreases ACMS performance.

TSC_USERNAME

Is the OpenVMS user name used by the TSC. The default user name is SYSTEM. See Chapter 10 in this manual for information about the privileges and quotas you assign to TSC_USERNAME.

TWS_POOLSIZE

Controls the overall size of the temporary pools that task workspaces use when a task is started. When you start a task, the group and user workspaces the task uses, as well as system workspaces and task workspaces, are copied into temporary workspaces for use by the task. At any given time, the sum of all group, user, system, and task workspaces for all active tasks cannot exceed this number. The default value is 350 pages (VAX) or 1600 pagelets (Alpha). See Section A.5.7.3 for more information about workspace pools.

TWSC_POOLSIZE

Controls the overall size of the pool used to store information needed to allocate the task instance workspaces stored in the TWS_POOLSIZE pool. The default value of 50 pages (VAX) or 50 pagelets (Alpha) causes the same amount of pool to be allocated as in previous versions of ACMS. See Section A.5.7.3 for more information about workspace pools.

USERNAME_DEFAULT

Defines a default submitter user name account used for remote task submitters that do not have an individual proxy account, or for task submitters from non-ACMS agents. The default submitter user name account must be authorized by the OpenVMS Authorize Utility in the SYSUAF.DAT file.

WS_POOLSIZE

Specifies the number of OpenVMS pages that are allocated to the workspace pool used for the group and user workspaces. This number of pages is allocated for each application. The default value of 256 pages (VAX) or 256 pagelets (Alpha) causes the same amount of pool to be allocated as in previous versions of ACMS. See Section A.5.7.3 for more information about workspace pools.

WSC_POOLSIZE

Specifies the number of OpenVMS pages that are allocated to the pool used for the control information for the group and user workspaces. The default value is 128 pages (VAX) or 128 pagelets (Alpha). See Section A.5.7.3 for more information about workspace pools.

## 11.7.3 Parameter Values

Table 11-3 lists the ACMS parameters with their value ranges, their default values, and whether or not they are dynamic. The minus one (--1) value in the range column means the upper limit for the parameter is unlimited.

Table 11-3 ACMSGEN Parameter Values
Parameter | Range | Default | Dynamic
--- | --- | --- | ---
ACC_PRIORITY | 0 to 31 | 4 | no
ACC_USERNAME | none | SYSTEM | no
CP_PRIORITY | 0 to 31 | 4 | no
CP_SLOTS | 0 to --1 | 3 | no
CP_USERNAME | none | SYSTEM | no
MAX_APPL | 1 to --1 | 10 | no
MAX_LOGINS | 0 to --1 | 60 | yes
MAX_TTS_CP | 0 to --1 | 20§ | yes
MIN_CPIS | 0 to --1 | 2 | yes
MSS_MAXBUF | 512 to 65K bytes | 1024 bytes | no
MSS_MAXOBJ | 1 to --1 objects | 500 objects | no
MSS_PROCESS_POOL | 1 to --1 | 256 | no
MSS_POOLSIZE | 1 to --1 pages+ | 512 pages+ | no
| 1 to --1 s++ | 512 pagelets++ | no
MSS_NET_RETRY_TIMER | 1 to --1 | 10 | yes
NODE_NAME | none | none | no
PERM_CPS | 0 to --1 | 1 | yes
QTI_POLLING_TIMER | 1 to --1 | 5000 milliseconds | yes
QTI_PRIORITY | 0 to 31 | 4 | no
QTI_RETRY_TIMER | 1 to --1 | 1800 seconds | yes
QTI_SUB_TIMEOUT | 1 to --1 | 7200 seconds | yes
QTI_USERNAME | none | SYSTEM | no
TSC_PRIORITY | 0 to 31 | 4 | no
TSC_USERNAME | none | SYSTEM | no
TWS_POOLSIZE | 1 to --1 pages+ | 350 pages+ | no
| 1 to --1 pagelets++ | 1600 pagelets++ | no
TWSC_POOLSIZE | 1 to --1 pages+ | 50 pages+ | no
| 1 to --1 pagelets++ | 50 pagelets++ | no
USERNAME_DEFAULT | none | none | yes
WS_POOLSIZE | 1 to --1 pages+ | 256 pages+ | no
| 1 to --1 pagelets++ | 256 pagelets++ | no
WSC_POOLSIZE | 1 to --1 pages+ | 128 pages+ | no
| 1 to --1 pagelets++ | 128 pagelets++ | no

§This value is a guideline. Depending on the complexity of the DECforms IFDL, a smaller value might be more suitable. The value selected is application dependent.
+This value is VAX specific.
++This value is Alpha specific.

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