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Administering Transactions
This topic includes the following sections:
Before you begin, you should read Introducing Transactions. In addition, for container-managed transaction demarcation in EJB applications, you can configure the transaction timeout setting, as described in Setting Transaction Timeouts.
Modifying the UBBCONFIG File to Accommodate Transactions
This topic includes the following sections:
To accommodate transactions, you must modify the RESOURCES, MACHINES, GROUPS, and the INTERFACES or SERVICES sections of the application's UBBCONFIG file in the following ways:
For instructions about modifying these sections in the UBBCONFIG, see "Creating a Configuration File" in the Administration Guide.
Step 1: Specify Application-wide Transactions in the RESOURCES Section
Table 8-1 provides a description of transaction-related parameters in the RESOURCES section of the configuration file.
Parameter |
Meaning |
---|---|
MAXGTT |
Limits the total number of global transaction identifiers (GTRIDs) allowed on one machine at one time. The maximum value allowed is 2048, the minimum is 0, and the default is 100. You can override this value on a per-machine basis in the MACHINES section. Entries remain in the table only while the global transaction is active, so this parameter has the effect of setting a limit on the number of simultaneous transactions. |
CMTRET |
Specifies the initial setting of the TP_COMMIT_CONTROL characteristic. The default is COMPLETE. Following are its two settings:
Note: You should consult with the RM vendors to determine the appropriate setting. If any RM in the application uses the late commit implementation of the XA standard, the setting should be COMPLETE. If all the resource managers use the early commit implementation, the setting should be LOGGED for performance reasons. (You can override this setting with tpscmt().)
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Step 2: Create a Transaction Log (TLOG)
This section discusses creating a transaction log (TLOG), which refers to a log in which information on transactions is kept until the transaction is completed.
Creating the UDL
The Universal Device List (UDL) is like a map of the BEA Tuxedo file system. The UDL gets loaded into shared memory when an application is booted. To create an entry in the UDL for the TLOG device, create the UDL on each machine using global transactions. If the TLOGDEVICE is mirrored between two machines, it is unnecessary to do this on the paired machine. The Bulletin Board Liaison (BBL) then initializes and opens the TLOG during the boot process.
To create the UDL, enter a command using the following format, before the application has been booted:
tmadmin -c crdl -z config -b blocks
where
-z config |
Specifies the full path name for the device where you should create the UDL. |
-b blocks |
Specifies the number of blocks to be allocated on the device. |
config |
Should match the value of the TLOGDEVICE parameter in the MACHINES section of the UBBCONFIG file. |
Note: In general, the value that you supply for blocks should not be less than the value for TLOGSIZE. For example, if TLOGSIZE is specified as 200 blocks, specifying -b 500 would not cause a degradation.
For more information about storing the TLOG, see the Installation Guide.
Defining Transaction-related Parameters in the MACHINES Section
You can define a global transaction log (TLOG) using several parameters in the MACHINES section of the UBBCONFIG file. You must manually create the device list entry for the TLOGDEVICE on each machine where a TLOG is needed. You can do this either before or after TUXCONFIG has been loaded, but it must be done before the system is booted.
Note: If you are not using transactions, the TLOG parameters are not required.
Table 8-2 provides a description of transaction-related parameters in the MACHINES section of the configuration file.
Parameter |
Meaning |
---|---|
TLOGNAME |
The name of the DTP transaction log for this machine. |
TLOGDEVICE |
Specifies the WebLogic Enterprise or BEA Tuxedo file system that contains the DTP transaction log (TLOG) for this machine. If this parameter is not specified, the machine is assumed not to have a TLOG. The maximum string value length is 64 characters. |
TLOGSIZE |
The size of the TLOG file in physical pages. Its value must be between 1 and 2048, and its default is 100. The value should be large enough to hold the number of outstanding transactions on the machine at a given time. One transaction is logged per page. The default should suffice for most applications. |
TLOGOFFSET |
Specifies the offset in pages from the beginning of TLOGDEVICE to the start of the VTOC that contains the transaction log for this machine.The number must be greater than or equal to 0 and less than the number of pages on the device. The default is 0. TLOGOFFSET is rarely necessary. However, if two VTOCs share the same device or if a VTOC is stored on a device (such as a file system) that is shared with another application, you can use TLOGOFFSET to indicate a starting address relative to the address of the device. |
Creating the Domains Transaction Log (BEA Tuxedo Servers)
This section applies to the BEA Tuxedo system only.
You can create the Domains transaction log before starting the Domains gateway group by using the following command:
dmadmin(1) crdmlog (crdlog) -d local_domain_name
Create the Domains transaction log for the named local domain on the current machine (the machine on which dmadmin is running). The command uses the parameters specified in the DMCONFIG file. This command fails if the named local domain is active on the current machine or if the log already exists. If the transaction log has not been created, the Domains gateway group creates the log when it starts up.
Step 3: Define Each Resource Manager (RM) and the Transaction Manager Server in the GROUPS Section
Additions to the GROUPS section fall into two categories:
(the minimum is 2, the maximum is 10, and the default is 3).
A null transactional manager server does not communicate with any resource manager. It is used to exercise an application's use of the transactional primitives before actually testing the application in a recoverable, real environment. This server is named TMS and it simply begins, commits, or terminates without talking to any resource manager.
The following sample GROUPS section derives from the bankapp banking application:
BANKB1 GRPNO=1 TMSNAME=TMS_SQL TMSCOUNT=2
OPENINFO="TUXEDO/SQL:<APPDIR>/bankdl1:bankdb:readwrite"
Table 8-3 describes the transaction values specified in this sample GROUPS section.
Transaction Value |
Meaning |
---|---|
BANKB1 GRPNO=1 TMSNAME=TMS_SQL\ TMSCOUNT=2 |
Contains the name of the transaction manager server (TMS_SQL) and the number (2) of these servers to be booted in the group BANKB1 |
TUXEDO/SQL |
Published name of the resource manager |
<APPDIR>/bankdl1 |
Includes a device name |
bankdb |
Database name |
readwrite |
Access mode |
Characteristics of the TMSNAME, TMSCOUNT, OPENINFO, and CLOSEINFO Parameters
Table 8-4 lists the characteristics of the TMSNAME, TMSCOUNT, OPENINFO, and CLOSEINFO parameters.
Parameter |
Characteristics |
---|---|
TMSNAME |
Name of the transaction manager server executable. Required parameter for transactional configurations. TMS is a null transactional manager server. |
TMSCOUNT |
Number of transaction manager servers (must be between 2 and 10). Default is 3. |
OPENINFO CLOSEINFO |
Represents information to open or close a resource manager. Content depends on the specific resource manager. Starts with the name of the resource manager. Omission means the resource manager needs no information to open. |
Step 4: Enable an Interface to Begin a Transaction
To enable an interface to begin a transaction, you change different sections in the UBBCONFIG file, depending on whether you are configuring a WebLogic Enterprise CORBA server or BEA Tuxedo server:
Changing the INTERFACES Section (WebLogic Enterprise CORBA Servers)
The INTERFACES section in the UBBCONFIG file supports WebLogic Enterprise CORBA interfaces:
Note: To work properly, this feature depends on collaboration between the system designer and the administrator. If the administrator sets this value to Y without prior knowledge of the transaction policy defined by the developer in the interface's ICF or XML file, the actual run time effect of the parameter might be unknown.
(231 - 1, or about 70 years). A value of zero implies there is no timeout for the transaction. (The default is 30 seconds.)
Note: For EJB and RMI applications, the AUTOTRAN and TRANTIME settings are ignored.
Table 8-5 describes the characteristics of the AUTOTRAN, TRANTIME, and FACTORYROUTING parameters.
Parameter |
Characteristics |
---|---|
AUTOTRAN |
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TRANTIME |
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FACTORYROUTING |
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Changing the SERVICES Section (BEA Tuxedo Servers)
The following are three transaction-related features in the SERVICES section:
Note: Generally, clients are the best initiators of transactions because a service has the potential of participating in a larger transaction.
Note: For EJB and RMI applications, the AUTOTRAN and TRANTIME settings are ignored.
Table 8-6 describes the characteristics of the AUTOTRAN, TRANTIME, and ROUTING parameters:
Parameter |
Characteristics |
---|---|
AUTOTRAN |
Makes a service the initiator of a transaction. Relieves the client of the transactional burden. If a transaction already exists, a new one is not started. Default is N. |
TRANTIME |
Represents the timeout for the AUTOTRAN transactions. Valid values are between 0 and 231 - 1, inclusive. 0 represents no timeout. Default is 30 seconds. |
ROUTING |
Points to an entry in the ROUTING section where data-dependent routing is specified for transactions that request this service. |
Modifying the Domain Configuration File to Support Transactions (WebLogic Enterprise Servers)
This topic includes the following sections:
To enable transactions across domains, you need to set parameters in both the DM_LOCAL_DOMAINS and the DM_REMOTE_SERVICES sections of the Domains configuration file (DMCONFIG). Entries in the DM_LOCAL_DOMAINS section define local domain characteristics. Entries in the DM_REMOTE_SERVICES section define information on services that are imported and that are available on remote domains.
Characteristics of the DMTLOGDEV, DMTLOGNAME, DMTLOGSIZE, MAXRDTRAN, and MAXTRAN Parameters
The DM_LOCAL_DOMAINS section of the Domains configuration file identifies local domains and their associated gateway groups. This section must have an entry for each gateway group (Local Domain). Each entry specifies the parameters required for the Domains gateway processes running in that group.
Table 8-7 provides a description of the five transaction-related parameters in this section: DMTLOGDEV, DMTLOGNAME, DMTLOGSIZE, MAXRDTRAN, and MAXTRAN.
Parameter |
Characteristics |
---|---|
DMTLOGDEV |
Specifies the BEA Tuxedo file system that contains the Domains transaction log (DMTLOG) for this machine. The DMTLOG is stored as a BEA Tuxedo VTOC table on the device. If this parameter is not specified, the Domains gateway group is not allowed to process requests in transaction mode. Local domains running on the same machine can share the same DMTLOGDEV file system, but each local domain must have its own log (a table in the DMTLOGDEV) named as specified by the DMTLOGNAME keyword. |
DMTLOGNAME |
Specifies the name of the Domains transaction log for this domain. This name must be unique when the same DMTLOGDEV is used for several local domains. If a value is not specified, the value defaults to the string DMTLOG. The name must contain 30 characters or less. |
DMTLOGSIZE |
Specifies the numeric size of the Domains transaction log for this machine (in pages). It must be greater than zero and less than the amount of available space on the BEA Tuxedo file system. If a value is not specified, the value defaults to 100 pages. Note: The number of domains in a transaction determine the number of pages you must specify in the DMTLOGSIZE parameter. One transaction does not necessarily equal one log page. |
MAXRDTRAN |
Specifies the maximum number of domains that can be involved in a transaction. It must be greater than zero and less than 32,768. If a value is not specified, the value defaults to 16. |
MAXTRAN |
Specifies the maximum number of simultaneous global transactions allowed on this local domain. It must be greater than or equal to zero, and less than or equal to the MAXGTT parameter specified in the TUXCONFIG file. If not specified, the default is the value of MAXGTT. |
The DM_REMOTE_SERVICES section of the Domains configuration file identifies information on services imported and available on remote domains. Remote services are associated with a particular remote domain.
Table 8-8 describes the two transaction-related parameters in this section: AUTOTRAN and TRANTIME.
Note: For EJB and RMI applications, these settings are ignored.
Parameter |
Characteristics |
---|---|
AUTOTRAN |
Used by gateways to automatically start/terminate transactions for remote services. This capability is required if you want to enforce reliable network communication with remote services. You specify this capability by setting the AUTOTRAN parameter to Y in the corresponding remote service definition. |
TRANTIME |
Specifies the default timeout value in seconds for a transaction automatically started for the associated service. The value must be greater than or equal to zero, and less than 2147483648. The default is 30 seconds. A value of zero implies the maximum timeout value for the machine. |
Sample Distributed Application Using Transactions
This topic includes the following sections:
This topic describes a sample configuration file for the Bankapp application, a sample CORBA application that enables transactions and distributes the application over three sites. The application includes the following features:
The configuration file includes seven sections: RESOURCES, MACHINES, GROUPS, NETWORK, SERVERS, SERVICES, and ROUTING.
Note: Although this sample is a CORBA application, the principles apply to EJB applications as well, except that the ROUTING section is not used in EJB applications, nor are the TRANTIME and AUTOTRAN parameters in the INTERFACES section.
RESOURCES Section
The RESOURCES section shown in Listing 8-1 specifies the following parameters:
Listing 8-1 Sample RESOURCES Section
*RESOURCES
#
IPCKEY 99999
UID 1
GID 0
PERM 0660
MAXACCESSERS 25
MAXSERVERS 25
MAXSERVICES 40
MAXGTT 20
MASTER SITE3, SITE1
SCANUNIT 10
SANITYSCAN 12
BBLQUERY 180
BLOCKTIME 30
DBBLWAIT 6
OPTIONS LAN, MIGRATE
MODEL MP
LDBAL Y
The MACHINES section shown in Listing 8-2 specifies the following parameters:
Listing 8-2 Sample MACHINES Section
*MACHINES
Gisela LMID=SITE1
TUXDIR="/usr/tuxedo"
APPDIR="/usr/home"
ENVFILE="/usr/home/ENVFILE"
TLOGDEVICE="/usr/home/TLOG"
TLOGNAME=TLOG
TUXCONFIG="/usr/home/tuxconfig"
TYPE="3B600"
romeo LMID=SITE2
TUXDIR="/usr/tuxedo"
APPDIR="/usr/home"
ENVFILE="/usr/home/ENVFILE"
TLOGDEVICE="/usr/home/TLOG"
TLOGNAME=TLOG
TUXCONFIG="/usr/home/tuxconfig"
TYPE="SEQUENT"
juliet LMID=SITE3
TUXDIR="/usr/tuxedo"
APPDIR='/usr/home"
ENVFILE="/usr/home/ENVFILE"
TLOGDEVICE="/usr/home/TLOG"
TLOGNAME=TLOG
TUXCONFIG="/usr/home/tuxconfig"
TYPE="AMDAHL"
The GROUPS and NETWORK sections shown in Listing 8-3 specify the following parameters:
Listing 8-3 Sample GROUPS and NETWORK Sections
*GROUPS
DEFAULT: TMSNAME=TMS_SQL TMSCOUNT=2
BANKB1 LMID=SITE1 GRPNO=1
OPENINFO="TUXEDO/SQL:/usr/home/bankdl1:bankdb:readwrite"
BANKB2 LMID=SITE2 GRPNO=2
OPENINFO="TUXEDO/SQL:/usr/home/bankdl2:bankdb:readwrite"
BANKB3 LMID=SITE3 GRPNO=3
OPENINFO="TUXEDO/SQL:/usr/home/bankdl3:bankdb:readwrite"
*NETWORK
SITE1 NADDR="0X0002ab117B2D4359"
BRIDGE="/dev/tcp"
NLSADDR="0X0002ab127B2D4359"
SITE2 NADDR="0X0002ab117B2D4360"
BRIDGE="/dev/tcp"
NLSADDR="0X0002ab127B2D4360"
SITE3 NADDR="0X0002ab117B2D4361"
BRIDGE="/dev/tcp"
NLSADDR="0X0002ab127B2D4361"
SERVERS, SERVICES, and ROUTING Sections
The SERVERS, SERVICES, and ROUTING sections shown in Listing 8-4 specify the following parameters:
Note: The ROUTING section is not used in EJB or RMI applications.
Listing 8-4 Sample SERVERS, SERVICES, and ROUTING Sections
*SERVERS
DEFAULT: RESTART=Y MAXGEN=5 REPLYQ=N CLOPT="-A"
TLR SRVGRP=BANKB1 SRVID=1 CLOPT="-A -- -T 100"
TLR SRVGRP=BANKB2 SRVID=3 CLOPT="-A -- -T 400"
TLR SRVGRP=BANKB3 SRVID=4 CLOPT="-A -- -T 700"
XFER SRVGRP=BANKB1 SRVID=5 REPLYQ=Y
XFER SRVGRP=BANKB2 SRVID=6 REPLYQ=Y
XFER SRVGRP=BANKB3 SRVID=7 REPLYQ=Y
*SERVICES
DEFAULT: AUTOTRAN=N
WITHDRAW ROUTING=ACCOUNT_ID
DEPOSIT ROUTING=ACCOUNT_ID
TRANSFER ROUTING=ACCOUNT_ID
INQUIRY ROUTING=ACCOUNT_ID
*ROUTING
ACCOUNT_ID FIELD=ACCOUNT_ID BUFTYPE="FML"
RANGES="MON - 9999:*,
10000 - 39999:BANKB1
40000 - 69999:BANKB2
70000 - 100000:BANKB3
""
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