Reading in DCN options
Function
The SESDCN control statement SET-DCN-OPTIONS causes the DCN options to be read in.
DCN options parametrize the SESDCN distribution component and thus define the essential properties of SESDCN operation. SESAM/SQL-DCN recognizes the following options:
DCN-OPTION | Short description of function |
ADMINISTRATOR | Assigns administrator authorization |
COLDSTART | Requests a cold start. |
DCN-IDENTIFICATION | Assigns a DCN name and configuration name. |
REMOTE-ACCESS | Permits access from a remote computer. |
SESDLG-PASSWORD | Assigns a password. |
SYSTEM-LIMITS | Specifies limit values for the permitted number of users and transaction |
Table 13: Functions of the DCN options
You can modify some DCN options dynamically using administration statements (see section “SESDCN administration statements”).
You must enter the SET-DCN-OPTIONS statement once and once only.
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Operands
DCN-IDENTIFICATION =
Identifies the SESDCN distribution component to be parametrized.
DCN-IDENTIFICATION = *STD
The SESDCN distribution component is identified by default values. These are described under PARAMETERS(...).
DCN-IDENTIFICATION = *PARAMETERS(...)
CONFIGURATION-NAME = *BLANK / <alphanum-name 1..1>
Name of the configuration to which the SESDCN component is assigned.The configuration name must be unique throughout the network so that, if necessary, it is possible to execute a restart on a machine other than the cold-start computer (see "Restarting SESDCN on a backup computer").
DCN-NAME = *BLANK / <alphanum-name 1..1>
Name of the distribution component to be parametrized.
The default is a blank.
SYSTEM-LIMITS =
Specifies limit values for the SESDCN session.
SYSTEM-LIMITS = *STD
The default limit values of the SESDCN session apply. These are described under PARAMETERS(...).
SYSTEM-LIMITS = *PARAMETERS(...)
USERS = 128 / <integer 1..16000>
Maximum number of permitted users in the session.
In timesharing mode, the users are the interactive or batch programs that run simultaneously. In transaction mode, they are the simultaneously open transaction conversations defined by the active terminals.
The default value for USERS is 128. The upper limit for the number of concurrent users depends on the total number of users your SESAM/SQL-DCN license permits. The license specifies the total number of DCN option USERS of all master DCNs in a hardware installation.
You cannot change the number of permitted users specified here in the current session; you first have to restart SESDCN. Note that you cannot restart SESDCN until all the application programs involved and all the SESAM/SQL-DBHs and SESDCNs have been terminated.
SESDCN sets up the number of areas specified by USERS for user tables in the common memory pool. The common memory pool is created by the first SESDCN in a configuration to be loaded, the master DCN. The entry for USERS is ignored by subsequently loaded SESDCNs of the same configuration.
You should therefore assign the same value for USERS to all master DCNs in the session.
APPLICATIONS = 64 / <integer 1..128>
Maximum number of transaction applications that can participate in the SESDCN session. The default is 64.
LOCK-TIME = 8 / <integer 1..999>
Specifies the time in minutes after which an inactive transaction locking another transaction is rolled back. Default: 8 minutes.
INACTIVITY-TIME = 12 / <integer 1..999>
Specifies the time in minutes after which an inactive open transaction is rolled back. Transactions locked by other transactions are not affected by this. The value for INACTIVITY-TIME must be greater than or equal to that for LOCK-TIME. Default: 12 minutes.
COLDSTART =
Requests a cold start.
COLDSTART = *NO
This is the default.
When a restart is executed on a backup computer (see "Restarting SESDCN on a backup computer"), the host names in the distribution rules of the remote DCNs are updated only in the memory pool and in DCN LOG. Any input files of the remote DCNs are therefore not affected by this updating. The next cold start would cancel the updating.
The default is therefore that a warm start is executed when the SESDCN acting as the remote DCN is started again after a distribution rule has been updated (because a SESDCN has been restarted on a backup computer). When a warm start is executed, SESDCN evaluates the updated distribution rule backed up in DCN LOG.
COLDSTART = *YES
Causes a cold start to be executed even if the distribution rule of this SESDCN has been updated (because of a SESDCN restart on a backup computer). When a cold start is executed, SESDCN evaluates the SESDCN control statements in the input or procedure files. Any entries in DCN LOG that contradict these are ignored.
You cannot force a cold start if there are still transactions in the PTC state. If this is the case, SESDCN carries out a warm start.
Note that the host names in the ADD-NETWORK-LINK-LIST statement must be up to date.
REMOTE-ACCESS =
Specifies whether or not access is permitted from a remote computer.
REMOTE-ACCESS = *ALLOWED
This is the default. Access from a remote computer is permitted.
REMOTE-ACCESS = *NOT-ALLOWED
Remote access is not permitted. SESDCN does not accept requests from remote computers.
SESDLG-PASSWORD =
Gives the distribution components the password with which you can access the SESDCN backup file. The password protection applies to write and read accesses. At the same time, this also protects the file from being deleted.If there is not a SESDCN backup file at the time when the SESDCN session is started, the file is generated by SESDCN and is password-protected if a password is specified in the SESDLG-PASSWORD operand.
SESDLG-PASSWORD = *NONE
No password is specified.
SESDLG-PASSWORD = <c-string 1..4> / <x-string 1..8> /
<integer -2147483648..2147483647>
Gives the specified password to the distribution components.
If there is already a SESDCN backup file without password protection at the time when SESDCN is started under the name assigned with the link name SESDLG or under the default name, then this file will not be protected by a password from SESDCN even when the SESDLG-PASSWORD operand contains a value.
If an existing SESDCN backup file is assigned a password later or a password is to be changed, you must do this using the SDF command MODIFY-FILE-ATTRIBUTES.
ADMINISTRATOR =
Specifies the user or user group authorized to issue administration statements using the CALL interface and SESADM.
ADMINISTRATOR = *NONE
Administration using the CALL interface and SESADM is not possible. The MODIFY-ADMINISTRATION administration statement is also rejected.
ADMINISTRATOR = *ANY(...)
Users who are not system administrators can also issue administration statements using the CALL interface and SESADM.
PASSWORD = <c-string 3..3> / <x-string 5..6>
Password providing protection against unauthorized administration using the CALL interface and SESADM
ADMINISTRATOR = *TIME-SHARING-USER(...)
Only the system administrator can issue administration statements using the CALL interface and SESADM . The administrator is a timesharing user and is identified by the system user identification.
PASSWORD = <c-string 3..3> / <x-string 5..6>
Password providing protection against unauthorized administration using the CALL interface and SESADM
HOST-NAME = <name 1..8>
Name of the computer from which administration is to be carried out
USER-ID = <name 1..8>
User ID of the system administrator
ADMINISTRATOR = *APPLICATION-USER(...)
Only the system administrator can issue administration statements using the CALL interface and SESADM. The system administrator is an application user and is identified by the system user identification.
PASSWORD = <c-string 3..3> / <x-string 5..6>
Password providing protection against unauthorized administration using the CALL interface and SESADM
HOST-NAME = <text 1..8>
Name of the computer from which administration is to be carried out
APPLICATION-NAME = <text 1..8>
Name of the application from which administration is to be carried out
CUSTOMER-NAME = <text 1..8>
Name of the user. If the system administrator is working under openUTM, the KDCSIGN name must be specified here. If the system administrator is working under DCAM, the name by which the system administrator identifies himself or herself at the program interface must be specified.