Correct operation of the ATM transaction manager and the Adabas Transaction Manager client proxy depends on the settings of client runtime controls. These are defined and maintained using Online Services. Their settings determine the logic to be used by the proxy during transaction processing. These settings should be determined according to production system requirements, and should be tested before being used in production.
At execution time, the Adabas Transaction Manager client proxy checks the Adabas System Coordinator system file for client runtime controls that match the name of the currently executing job. If no exact match is found, a wild-card match is attempted. Failing this, the control values for job name DEFAULT will be returned. If there is no definition under the name DEFAULT, hard-coded default values in the Adabas Transaction Manager kernel will be used.
It is therefore important to set appropriate values for each job that could load and execute the Adabas Transaction Manager client proxy.
Note:
The NumberOfLogRecordEntries
control setting requires particular attention. This setting determines the
amount of memory, per client session, that is allocated for logging diagnostic
information. In a TP system that services many users, a setting of 100, for
example, could quickly consume a large amount of memory. In such systems,
choose a small value for this setting. See the section
Client
Sessions for more information.
This section describes each ATM runtime control:
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime |
Indicates whether or not ATM is to provide transaction coordination for this client session. |
ON | OFF | OFF |
Possible values:
| Value | Description |
|---|---|
| ON | Users will perform distributed transaction processing, and ATM is to provide transaction coordination. |
| OFF | ATM is not to be used for coordinating transactions for users in this client session. |
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime |
Identifies the Adabas System Coordinator group in which the client session or TP system will execute. |
Any valid Adabas System Coordinator group name | A valid group name must be provided |
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Sets the maximum number of databases with which a client session can have an active session at one time. | number | 4 |
The setting should include all databases without regard to their
DTP parameter settings.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not internal logging is to be performed, and if so, how much space, per client session, will be used for this purpose. | 0-4096 | 0 |
The ATM client proxy is capable of logging internal events for diagnostic purposes. The log buffer area is reused cyclically.
Possible values:
| Value | Description |
|---|---|
| 0 | The client proxy will not acquire log buffer areas and will not log internal events. |
| 1-4096 | The number of entries to be reserved for internal event logging. Each entry requires 96 bytes. |
Note:
Do not specify a high value for a TP system that services a large
number of users since this may result in memory becoming exhausted.
The NumberLogRecordEntries client control has no
effect on the logging that takes place in the transaction manager’s address
space. Logging by the transaction manager is controlled by the ADARUN parameter
TMLOG.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Determines the action to be taken whenever an unsolicited syncpoint request is received. | GLOBAL | LOCAL | LOCAL |
The setting of this control determines what action is to be taken whenever an unsolicited syncpoint request is received, that is, whether a decision to commit or back out a global transaction is to be made by the application program itself using its local ATM client proxy, or by a software component other than ATM or ATM client proxy.
Unsolicited syncpoint requests can occur if:
The option Client-sideTransactionManager is in
effect and ATM could receive a request to commit or back out a global
transaction other than through an ET or
BT command; or
the ATM transaction manager executes with the parameter setting
TMSYNCMGR=RRMS; or
an application could cause a participating trigger to execute,
causing an ET command to be issued, all without the
knowledge of the user’s local ATM client proxy.
Possible values are:
| Value | Description |
|---|---|
| LOCAL: |
Decision to commit or back out a global transaction is to be made by the application program itself using its local ATM client proxy. If unsolicited syncpoints are not valid in your environment,
specify LOCAL so that any unsolicited syncpoint request is reported as an
error. Specifying |
| GLOBAL |
Decision to commit or back out a global transaction can be made by a software component other than ATM or ATM client proxy. GLOBAL is required if unsolicited syncpoint requests are acceptable. Note: |
When running with the Client-side Transaction
Manager option set to YES in a CICS/RMI environment, a decision to
commit or back out a global transaction can occur in several ways:
the application program issues ET or
BT;
the application program issues EXEC CICS
SYNCPOINT (or SYNCPOINT ROLLBACK);
the CICS task terminates, normally or abnormally, when updates are pending.
In the first case, the ATM client proxy is aware of the syncpoint decision.
In all other cases, from the client proxy’s point of view, the syncpoint is unsolicited. If the client session is at global transaction status, an unsolicited syncpoint has no effect on Adabas databases, other than to cause held ISNs to be released. On the other hand, if an unsolicited syncpoint occurs when Adabas changes are pending, ATM is instructed to commit the changes; in this case also, held ISNs are released.
If such unsolicited syncpoints are acceptable in your CICS system,
specify GLOBAL for the TransactionControl client control
- otherwise, specify LOCAL to treat unsolicited syncpoint requests as
errors.
Most CICS applications run in pseudo-conversational mode; that is, the
current CICS task terminates when a screen I/Os occurs. If ATM CICS/RMI is
installed and active, and client runtime control
TransactionModel is set to MESSAGE, an application that
runs in pseudo-conversational mode cannot keep an Adabas transaction open
across screen I/Os because an implied (unsolicited) commit syncpoint occurs at
every screen I/O. In this mode, it is not possible for a transaction to remain
open across screen I/Os. See the TransactionModel control
for details of a different way of responding to unsolicited syncpoints.
If the client control TransactionControl is set
to LOCAL and the syncpoint resulted in Adabas changes being committed, the next
Adabas call following a screen I/O returns response code 243.
Various Natural features including some SYSSEC functions maintain open
Adabas transactions across screen I/Os. In a CICS/RMI environment operating
with the client runtime control TransactionModel set to
MESSAGE, such functions are likely to
fail with a NAT3243 error when
TransactionControl is set to LOCAL; or
be unable to back out in case of errors when
TransactionControl is set to GLOBAL; or
fail with response code 144.
You should therefore execute Natural system functions in one of the following ways:
execute Natural system functions in a system other than CICS, or in a CICS system using a link module in which the RMI is not active; or
execute Natural system functions in a client session that operates
with the client runtime control TransactionModel set to
DYNAMIC; or
execute Natural system functions in conversational mode when using the CICS Resource Manager Interface.
When ATM’s RRMS interface is active, a decision to commit or back out a global transaction can occur in several ways:
the application program issues ET or
BT;
the application program issues SRRCMIT or
SRRBACK;
the application or some other agent issues
ATRCMIT or ATRBACK.
In the first case, the ATM’s client proxy is aware of the syncpoint decision. In other cases, from ATM’s point of view, the syncpoint is unsolicited. If the client session is at global transaction status, an unsolicited syncpoint has no effect on Adabas databases, other than to cause held ISNs to be released. On the other hand, if an unsolicited syncpoint occurs when Adabas changes are pending, ATM is instructed to commit the changes; in this case, also, held ISNs will be released.
If unsolicited syncpoints are acceptable in your system, set the client
control TransactionControl to GLOBAL - otherwise, set
TransactionControl to LOCAL to treat unsolicited
syncpoint requests as errors. If TransactionControl is
set to LOCAL and an unsolicited syncpoint causes a client sessions's Adabas
changes to be committed, the next Adabas call issued by the user returns
response code 243.
If ATM runs with the
HostSystemTransactionManager option is specified for
IMS/TM systems whose transactions are coordinated by RRMS,
TransactionControl must be set to GLOBAL for these IMS
systems.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not the ATM client proxy is
to switch a client session from DTP to serial ET/BT
mode if the local ATM transaction manager becomes unavailable.
|
YES | NO | FORCE | FORCE |
Possible values:
| Value | Description |
|---|---|
| YES | The ATM client proxy is to switch a client
session from DTP to serial ET/BT mode if the local
transaction manager becomes unavailable. A response code will be returned to
indicate that the local TM is unavailable.
|
| NO | The ATM client proxy is not to switch a client
session from DTP to serial ET/BT mode if the local
TM becomes unavailable.
|
| FORCE | A client session is to be switched to serial mode if necessary. No notification is provided. |
For more information regarding DTP and Serial mode processing, refer to the section Processing Modes.
Note:
If ATM automatically switches a client session to serial
ET/BT mode when the session has a transaction open,
the client might receive unexpected response codes, even if the runtime control
value for serial processing is set to FORCE. For example, the transaction might
be backed out, and response 9 returned to the client. Other response codes,
such as response 240 subcode 88, might be given, depending on how far the
transaction had progressed, and there is a possibility that the transaction
will remain unresolved until the ATM transaction manager is once again able to
carry out its responsibilities. Even so, the setting of value FORCE will ensure
minimum disruption when a switch to serial ET/BT
mode is necessary, and will probably allow most clients to continue processing
without noticing the switch.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether the client’s local Transaction
Manager should use serial ET commands to remote RMs
which are not signed on for Distributed Transaction Processing in the client’s
System Coordinator group.
|
YES | NO | YES |
Possible values:
| Value | Description |
|---|---|
| YES | If the client session changes one or more remote
RMs which are currently not signed on for Distributed Transaction Processing,
to any Transaction Manager within the scope of the client’s System Coordinator
Group, the client’s local Transaction Manager will treat these RMs as if they
were running with DTP=NO. That is, such a transaction
will be committed in the normal way, using the two-phase commit protocol with
respect to any signed-on RMs, and then ATM will issue
ET commands to any changed remote RMs that are not
signed on for DTP.
|
| NO | If the client session attempts a transaction that changes an RM which is currently not signed on for DTP to any Transaction Manager within the scope of the client’s COR Group, the transaction will usually be rejected with a suitable response code. In some circumstances the transaction may be allowed to complete normally, but only if it can be completed safely without the need of a two-phase commit operation. |
Note:
If YES is specified, and a transaction changes one or more remote
RMs which are not signed on for DTP, and a system or component failure occurs
during the commit process, ATM cannot guarantee integrity of the transaction.
Note:
If the EmergencySerialETCommands control is
set to YES or FORCE, and a client session is switched into serial ET/BT mode,
serial remote RM coordination will take effect as long as the session is in
serial ET/BT mode, regardless of the setting of the
AllowSerialRemoteRMCoordination control.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not the ATM client proxy is
to generate an OP command when a session uses a
database without having issued an OP.
|
NO | YES | NO |
Possible values:
| Value | Description |
|---|---|
| NO | The ATM client proxy will not generate
OP commands on behalf of clients.
|
| YES | Whenever a client session uses a new database
for which no OP command has been issued, the ATM
client proxy will issue an OP command on behalf of
the client.
|
This parameter has been replaced by the TransactionModel runtime
control.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Transaction model | MESSAGE | DYNAMIC | MESSAGE |
Possible values:
| Value | Description |
|---|---|
| MESSAGE | The message-based transaction model will be
used. According to this model, a syncpoint always takes place when processing
of a message is complete (normally, this means that screen I/O causes a
syncpoint). Syncpoints caused by ET,BT,OP and
CL commands are handled in the normal way.
Unsolicited syncpoints cause ATM to commit (or back out) changes made to Adabas
databases, and release held ISNs.
|
| DYNAMIC | The dynamic transaction model will be used.
According to this model, transactions are delimited by Adabas commands.
Unsolicited commit syncpoints are ignored by ATM; ET
and CL commands cause ATM to commit pending Adabas
changes. Unsolicited rollback syncpoints cause ATM to back out changes from
Adabas databases and release held ISNs.
|
Note:
Setting TransactionModel to MESSAGE is
equivalent to SYNCMODE=FULL with ATM Version 1.2.
Note:
Setting TransactionModel to DYNAMIC is
equivalent to SYNCMODE=ADABAS with ATM Version
1.2.
Note:
There is no TransactionModel setting
equivalent to SYNCMODE=ALL with ATM Version 1.2. The
reason is that there is no distinction between the settings
SYNCMODE=ALL and SYNCMODE=FULL
with more recent versions of ATM, since ATM will always cause held ISNs to be
released when a syncpoint takes place, unless directed to do otherwise by
command options and the ExtendedHold client
control.
For more information, see also the section Syncpoint Processing Options.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not a
BT command should cause ATM to request a rollback
syncpoint from the external transaction coordinator.
|
YES | NO | YES |
Possible values:
| Value | Description |
|---|---|
| YES | Any BT command will
cause ATM to request a rollback syncpoint from the external transaction
coordinator that controls the current transaction. If there is no external
transaction coordinator in use, this setting is ignored.
|
| NO | ATM will not request a rollback syncpoint from
any external coordinator when it processes a BT
command. Furthermore, if ATM itself decides that a backout must be performed,
it will not request a rollback from any external coordinator.
|
Regardless of the setting for this control, a
BT command causes all Adabas changes to be backed
out.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not a
CL command should cause ATM to request a commit
syncpoint from the external transaction coordinator.
|
YES | NO | YES |
Possible values:
| Value | Description |
|---|---|
| YES | Any CL command will
cause ATM to request a commit syncpoint from the external transaction
coordinator that controls the current transaction. If there is no external
transaction coordinator in use, this setting is ignored.
|
| NO | ATM will not request a commit syncpoint from any
external coordinator when it processes a CL command.
|
For IMS/TM systems for which the
HostSystemTransactionManager option is specified, a
setting of YES for the client control
GenerateExternalSyncpointOnCL will be ignored, and the
value NO will take effect.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not an
ET command should cause ATM to request a commit
syncpoint from the external transaction coordinator.
|
YES | NO | YES |
Possible values:
| Value | Description |
|---|---|
| YES | Any ET command will
cause ATM to request a commit syncpoint from the external transaction
coordinator that controls the current transaction. If there is no external
transaction coordinator in use, this setting is ignored.
|
| NO | ATM will not request a commit syncpoint from any
external coordinator when it processes an ET
command.
|
Regardless of the setting for this control,
ET command causes any pending Adabas changes to be
committed.
For IMS/TM systems for which the
HostSystemTransactionManager option is specified, a
setting of YES for the client control
GenerateExternalSyncpointOnET will be ignored, and the
value NO will take effect.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not transactions in this client environment are to be controlled by the environment's native syncpoint manager. | YES | NO | NO |
Possible values:
| Value | Description |
|---|---|
| YES | Transactions in this client environment are to be controlled by the environment's native syncpoint manager. |
| NO | Transactions in this client environment are not to be controlled by the environment's native syncpoint manager. |
Note:
CICS under z/OS or VSE/ESA is the only client environment for which
a setting of YES is currently supported for this control.
Note:
The Client-sideTransactionManager and
HostSystemTransactionManager options are mutually
exclusive. However, setting
Client-sideTransactionManager to YES does not preclude
the use of RRMS as an external transaction coordinator for client sessions in
other jobs or TP systems, since RRMS interfaces directly with the ATM client
sessions in other jobs or TP systems and not with the client proxy
When defining client runtime controls for a CICS/RMI environment:
Setting Client-sideTransactionManager to NO
means that ATM coordinates transactions in the normal way, but not under the
control of the CICS Syncpoint Manager. That is, even when the RMI is enabled,
no transaction coordination occurs between Adabas and other RMI-enabled
resource managers.
Setting Client-sideTransactionManager to YES
activates the RMI so that the CICS Syncpoint Manager coordinates transactions
across all resource managers.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether or not transactions in this client environment are to be controlled by the host system's native transaction manager. | YES | NO | NO |
Possible values:
| Value | Description |
|---|---|
| YES | Transactions in this client environment are to be controlled by the host system's native transaction manager. |
| NO | Transactions in this client environment are not to be controlled by the host system's native transaction manager. |
Caution:
If this control is set to YES for an inappropriate type of job or
client environment, or for a job or environment which has not been correctly
configured to use the host system’s transaction manager, sessions executing in
that job will experience response code 240, subcode 444, and will not function
correctly.
Note:
The setting YES is currently supported only for single-user,
single-TCB batch jobs or TSO sessions, and for Com-plete and IMS/TM systems,
running under z/OS.
Note:
The HostSystemTransactionManager and
Client-sideTransactionManager options are mutually
exclusive.
| Parameter Type | Use | Possible Values | Default |
|---|---|---|---|
| Client runtime | Indicates whether P and M options on
ET and BT commands will
be honored when a distributed transaction is terminated by a series of
ET or BT
commands.
|
YES | NO | NO |
Possible values:
| Value | Description |
|---|---|
| YES | P and M options on ET
and BT commands will be honored. For any application
environment in which prefetch or multifetch command options can be used, the
setting YES should be used.
|
| NO | P and M options on ET
and BT commands will not be honored.
|
If Adabas Vista is present in an application job or TP environment, the
value YES will take effect, regardless of the setting specified for the
ExtendedHold client control.
For more information on extended hold processing, see Extended Hold Processing in section Termination Commands: ET and BT.
