Change Session Maximum (CHGSSNMAX)

The Change Session Maximum (CHGSSNMAX) command is used to dynamically change the maximum number of sessions the local location allows to a mode.

When a change to the maximum number of sessions is made, the remote system is informed and allowed to negotiate for a lower session maximum. The remote system cannot negotiate a session maximum higher than the value specified for the local number of sessions specified. The resulting session maximum value is the current session maximum. Neither system may activate more sessions than the current session maximum.

If the requested session maximum is accepted or negotiated by the remote system, the value requested on this command is stored as the local session maximum; the remote system is not allowed to increase the current session maximum above the value stored as the local session maximum. This new value for the local session is only used the next time a new session maximum needs to be negotiated. The current session maximum, which controls how many sessions can be active between the local and remote location, is not changed if the command fails. If the request to change the session maximum is rejected by the remote system, the command ends abnormally and the local session maximum is changed as follows: If it is increasing, it is changed to the value specified; if it is decreasing, it is not changed.

This command is normally used by the system operator to control the number of sessions that can be active at the same time with a remote location. If the current number of active sessions is greater than the maximum number specified on the command, no new sessions are created until the number of active sessions falls below that specified on the command. If the current number of active sessions is less than the maximum number specified, sessions are not created until jobs requiring them are started. The value created by the systems remains in effect until another Change Session Maximum (CHGSSNMAX) command or an End Mode (ENDMOD) command is run for the same mode, or until all the device descriptions associated with the remote location are varied off.

NOTES:

  1. When this command is used to reduce the number of sessions with a remote system, the sessions that are ended first are the available locally controlled sessions, followed by any other available sessions. If the new session count is still not reached, other sessions are ended as jobs using them are completed or are canceled.
  2. When the CHGSSNMAX command is used to increase the maximum number of sessions that can be created with a remote system, the locally controlled sessions are made available first (depending on the negotiated values), and then other sessions are made available.
  3. The CHGSSNMAX command does not change the value specified for the MAXSSN parameter in the mode description; the Change Mode Description (CHGMODD) command must be used to permanently change the value. When the device is next varied on, the MAXSSN value from the mode description is used to limit the number of sessions instead of the MAXSSN value specified on a previous CHGSSNMAX command.

The APPC Programming book, SC41-5443 has more information on this command.

Parameters

Keyword Description Choices Notes
RMTLOCNAME Remote location Communications name Required, Positional 1
MAXSSN Maximum sessions 1-512 Optional
DEV Device Name, *LOC Optional, Positional 2
MODE Mode Communications name, *NETATR Optional, Positional 3
LCLLOCNAME Local location Communications name, *LOC, *NETATR Optional
RMTNETID Remote network identifier Communications name, *LOC, *NETATR, *NONE Optional

Remote location (RMTLOCNAME)

Specifies the remote location name.

This is a required parameter.

Maximum sessions (MAXSSN)

Specifies the number of sessions allowed with the remote system. This value represents the desired maximum session number for the specified mode name. It must be less than or equal to the limit for number of sessions defined in the mode description. This value can be negotiated to a lower value by the remote location; therefore, the value specified here is not necessarily the value that is used.

Valid values for this parameter are 1 through 512.

Device (DEV)

Specifies the name of the device description used with the remote location.

The possible values are:

*LOC
The device associated with the remote location is used. If several devices can be associated with the remote location, the system determines which device is used.
device-name
Specify the name of a device description that is associated with the remote location.

Mode (MODE)

Specifies the name of the mode to be changed.

The possible values are:

*NETATR
The mode in the network attributes is used.
BLANK
A mode name (consisting of 8 blank characters) is used.
mode-name
Specify a value, no more than 8 characters, used to identify the mode to be changed.

Note: SNASVCMG and CPSVCMG are reserved names and cannot be specified.

Local location (LCLLOCNAME)

Specifies the local location name.

The possible values are:

*LOC
The local location name is determined by the system.
*NETATR
The LCLLOCNAME value specified in the system network attributes is used.
local-location-name
Specify the local location name associated with the remote location.

Remote network identifier (RMTNETID)

Specifies the remote network ID that is used with the remote location.

The possible values are:

*LOC
The system selects the remote network ID.
*NETATR
The remote network identifier specified in the network attributes is used.
*NONE
No remote network identifier (ID) is used.
remote-network-id
Specify a remote network ID.

Examples

CHGSSNMAX   RMTLOCNAME(APPCRLOC)  DEV(APPCDEV)  MODE(APPC2)  MAXSSN(3)

This command changes the maximum number of sessions allowed by remote location APPCRLOC for mode APPC2 to a maximum of three.

Error messages

*ESCAPE Messages

CPF598B
The &1 command failed for one or more modes.