The LLR library provides an XA switch to emulate XA operations and several uniform APIs for LLR server/TMS. Configure LLR library in the RM file under ${TUXDIR}/udataobj as follows:

[LLR XA switch name]:[LLR XA switch variable]:[Link options]

The following table shows the LLR library details:

In general, the LLR XA switch variable is tuxllrsw_[name] and the LLR XA switch name is tuxllr_[name]. The related library name is libllr[name], where [name] consists of RM ID and implementation ID. For example, ora indicates Oracle database, and esql indicates embedded SQL.

Configure OPENINFO in the UBBCONFIG file in the following format:

[LLR XA switch name]:[open string]

The following table shows the details.

ORACLE_XA{+required_fields...} [+optional_fields...]

TuxLLR is a specific optional field for Tuxedo LLR, which defines the LLR table name. If not defined, the default name is used.

The LLR table is used to store the committing TLOG for transactions that involves LLR server. The default table name is TUXLLR_[DOMAINID]. If [DOMAINID] is empty, DOM is used. When you specify the LLR table name using TuxLLR, make sure different LLR tables are used for different tuxedo domains in a same non-XA resource; otherwise the recovery might work incorrectly.

In addition, ensure the RM user account used by LLR switch has the privilege to create and update the LLR table. Otherwise, errors might occur.

For example, a user might get the following message in Oracle database:

ORA-01950: no privileges on tablespace 'string'

This is because the user does not have privilege to allocate an extent in the specified tablespace. To solve the issue, grant the user appropriate system privilege or grant the user space resource on the tablespace.

LLR_DELSWAPSIZE numeric_value

Specifies the maximum completed LLR involved 2PC global transaction ID (gtrid) that can be stored in the swap area. By default, the value is 0. To enable LLR feature, specify a positive value.

LLR_DELDELAY numeric_value

Specifies a multiplier of the basic SCANUNIT between LLR completed records lazy deletions. The value must be greater than 0. If this parameter is not specified, the default is set so that SCANUNIT * LLR_DELDELAY is approximately 30 seconds, however, if the SCANUNIT value is greater than 30 seconds, LLR_DELDELAY is set to 1 if not specified.

Oracle Tuxedo takes an XA switch as a Oracle Tuxedo-specific LLR XA switch if the XA switch name prefix is tuxllr_.

As long as an application server is built with the LLR XA switch, Oracle Tuxedo treats it as an LLR server. The TMS servers built with the same LLR XA switch in the same group are treated as LLR TMS. The group that LLR server belongs to is an LLR group. The transaction involving an LLR server is an LLR involved transaction. The TLOG record of this transaction is stored in the LLR table instead of Oracle Tuxedo traditional TLOG file.

An LLR server/TMS must use the correct LLR XA switch. It means the RM and the implementation must be the same as the LLR library that provides the XA switch.

Following is an example of the LLR server (server.pc), which uses the embedded SQL to insert a record into an Oracle database table within a local transaction.

Listing

…
EXEC SQL INCLUDE sqlca;
EXEC SQL BEGIN DECLARE SECTION;
char mylog[200];
int mypid;
EXEC SQL END DECLARE SECTION;
int tpsvrinit(int argc, char *argv[])
{
      tpopen();
      mypid=getpid();
      return(0);
}
  void tpsvrdone()
{
  tpclose();
}
void ECHO(TPSVCINFO *rqst)
{
      strncpy(mylog, rqst->data,rqst->len);
      mylog[rqst->len-1] = 0;
      EXEC SQL INSERT INTO TUX_RAC_TAB(OWNER, DATA) VALUES(:mypid,
 :mylog);
      tpreturn(TPSUCCESS, 0, rqst->data, 0L, 0);/*do not commit the local
 transaction*/
}
…

Listing Configuring the RM File

tuxllr_oraesql:tuxllrsw_oraesql: -lllroraesql -L${ORACLE_LIB} -lclntsh 

Listing Configuring UBBCONFIG

*RESOURCE
…
MODEL             SHM

SCANUNIT          5

MAXGTT            600

LLR_DELDELAY      6

LLR_DELSWAPSIZE   500   
 
…
*MACHINES
“m1”   LMID=L1 TLOGSIZE=100
…
*GROUPS
GRP1   LMID=L1 GRPNO=10 TMSNAME="TMS_LLRORAESQL" TMSCOUNT=2

OPENINFO="tuxllr_oraesql:ORACLE_XA+SqlNet=orcl.tux1+ACC=P/scott/tiger”
…
server1 SRVGRP=GRP1 SRVID=10
…

Listing Building LLR Servers and TMS

…
${PROC} ${PROCFLAGS} iname=server.pc
buildserver -r tuxllr_oraesql -o server1 -f server.c
buildtms -r tuxllr_oraesql -o TMSLLRORAESQL
…