| Oracle® Transparent Gateway for DRDA Installation and User's Guide 10g Release 2 (10.2) for Microsoft Windows Part Number B16218-02 |
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| Oracle® Transparent Gateway for DRDA Installation and User's Guide 10g Release 2 (10.2) for Microsoft Windows Part Number B16218-02 |
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|
View PDF |
This chapter provides information about error messages and error codes. This chapter is specific to this release of the Oracle Transparent Gateway for DRDA, and it includes the following sections:
The gateway architecture involves a number of separate components. Any component might detect and report an error condition while processing SQL statements that refer to one or more DRDA database tables. This means that error situations can be complex, involving error codes and supporting data from multiple components. In all cases, however, the application ultimately receives a single Oracle error number or return code on which to act.
Because most gateway messages exceed the 70-character message area in the Oracle SQLCA, the programmatic interfaces and Oracle Call Interfaces that you use to access data through the gateway should use SQLGLM or OERHMS to view the entire text of messages. Refer to the programmer's guide to the Oracle precompilers for additional information about SQLGLM, and refer to the Oracle Call Interface Programmer's Guide for additional information about OERHMS.
Error conditions encountered when using the gateway can originate from many sources:
Errors detected by the Oracle integrating server
Errors detected by the gateway
Errors detected in the DRDA software, either on the requestor or server side
Communication errors
Errors detected by the server database
Errors detected by the Oracle integrating server are reported back to the application or tool with the standard ORA- type message. Refer to the Oracle Database Error Messages for descriptions of these errors. For example, the following error message occurs when an undefined database link name is specified:
ORA-02019: connection description for remote database not found
Errors in the ORA-9100 to ORA-9199 range are reserved for the generic gateway layer (components of the gateway that are not specific to DRDA). Messages in this range are documented in Oracle Database Error Messages.
Errors detected by the generic gateway are prefixed with HGO- and are documented in the Oracle Database Error Messages.
An example of an error message is:
HGO-00706: HGO: Missing equal sign for parameter in initialization file.
Errors detected in the DRDA gateway, on the requestor or server side, are usually reported with error code ORA-28500, followed by a gateway-specific expanded error message. There are two return codes reported in the expanded message:
drc specifies DRDA-specific errors which are documented in "Gateway Error Codes".
grc specifies generic gateway errors detected in the DRDA layer. These errors are documented in the Oracle Database Heterogeneous Connectivity Administrator's Guide.
Note:
Error code ORA-28500 was error code ORA-09100 prior to gateway version 8. Error code ORA-28501 was error code ORA-09101 prior to gateway version 8.The values in parentheses that follow the drc values are used for debugging by Oracle Support Services. The errp field indicates the program (requestor or server) that detected the error. If errmc is present, it lists any error tokens.
For example, the following error message is returned when the database name specified (XNAME) with the DRDA_REMOTE_NAME parameter in the initsid.ora file is not defined at the DRDA Server:
ORA-28500: connection from ORACLE to a non-Oracle system returned the message: TG4DRDA v10.2.0.1.0 grc=0, drc=-30061 (839C,0000), errp=GDJRFS2E errmc=XNAME
Communication errors are reported with an ORA-28501 followed by a gateway-specific expanded error message with drc=-30080 (SNA CPI-C error) or drc=-30081 (lost session). errmc indicates which CPI-C routine encounters the error, followed by the CPI-C error code and error number.
For example, the following error message is returned when there is a failure to establish a session because DRDA_CONNECT_PARM in the initsid.ora file specifies a Side Information Profile that is not defined:
ORA-28501: Target system communication error. TG4DRDA v10.2.0.1.0 grc=0, drc=-30081 (839C,0001), errp=GDJICRD errmc=Initialize_Conversation (CMINIT) 24 0
Refer to the appropriate Microsoft Windows or IBM Communication Server documentation for more information.
Errors detected by the server database are reported with an ORA-28500 Oracle Error followed by a gateway-specific expanded error message with drc=-777 (sqlcode follows). This is followed by another error message line that contains the sqlcode, sqlstate, errd (error array), and errmc (error tokens) returned from the DRDA Server database. Refer to IBM documentation for the specific database being used. Also refer to "Mapped Errors" for some SQL errors that get translated.
Note:
Error code ORA-28500 was error code ORA-09100 prior to gateway version 8. Error code ORA-28501 was error code ORA-09101 prior to gateway version 8.For example, the following error message indicates that the DRDA Server database did not recognize the collection ID or package name specified with the DRDA_PACKAGE_COLLID or DRDA_PACKAGE_NAME parameters in the initsid.ora file:
ORA-28500: Target system returned following message: TG4DRDA v10.2.0.1.0 grc=0, drc=-777 (839C,0000), errp=DSNXEPM sqlcode=-805, sqlstate=51002, errd=FFFFFF9C,0,0,FFFFFFFF,0,0 errmc=XB2V2R3..GSQL.A92617CB3FE5470DISTSERV
Some SQL errors are returned from the DRDA Server database and are translated to an Oracle error code. This is needed when the Oracle instance or gateway provides special handling of an error condition. The mapped sqlstate errors are:
Table 15-1 Mapped sqlstate Errors
| Description | sqlstate error | Oracle error |
|---|---|---|
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No rows selected |
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Unique index constraint violated |
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Object does not exist |
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Object name too long (more than 18 characters), and therefore object does not exist |
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Insufficient privileges |
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Invalid CCSID (unimplemented character set conversion) |
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Invalid user name/password; logon denied |
N/A |
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Divide by zero error |
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The following is an example of a translated "object does not existÓ error:
ORA-00942: table or view does not exist TG4DRDA v10.2.0.1.0 grc=0, drc=-942 (839C,0001), errp=DSNXEDST sqlcode=-204, sqlstate=52004, errd=32,0,0,FFFFFFFF,0,0 errmc=AJONES.CXDCX
Listed below are the common Oracle Transparent Gateway for DRDA error codesthat appear in the drc= field of the expanded error messages. If you get a drc value that does not appear here, contact Oracle Support Services.
DRDA_DEFAULT_CCSID in the initsid.ora file is not supported by the Oracle Transparent Gateway for DRDA.LANGUAGE parameter in the initsid.ora file is not supported.sqlcode and sqlstate indicate host database error. Use this information to fix your application.When developing applications, it is often useful to be able to see the exact SQL statements that are being passed through the gateway. This section describes setting correct trace parameters and setting up the debug gateway.
The Oracle server has a command for capturing the SQL query which is actually sent to the gateway. This command is called EXPLAIN PLAN. EXPLAIN PLAN is used to determine the execution plan that Oracle follows to run a specified SQL statement. This command inserts a row (describing each step of the execution plan) into a specified table.
If you are using cost-based optimization, then this command also determines the cost of running the statement. The syntax of the command is:
EXPLAIN PLAN [ SET STATEMENT_ID = 'text' ]
[ INTO [schema.]table [@dblink] ] FOR statement
For detailed information on this command, refer to the Oracle Database SQL Reference.
Note:
In most cases, EXPLAIN PLAN should be sufficient to extract the SQL query which is actually sent to the gateway, and thus sent to the DRDA Server. However, certain SQL statement forms have postprocessing performed on them in the gateway. The next section will describe setting up SQL tracing in the gateway.To enhance speed of the gateway, tracing was not built into the production gateway.
The product ships with a debug version of the gateway for the purposes of tracing and debugging applications.
This process entails changing the listener.ora file to use the debug gateway:
Log in as the Administrator user ID of the gateway and set up the environment.
Stop the Oracle Net Listener:
> lsnrctl stop
Edit the listener.ora with any text editor:
> notepad C:\Oracle\GTWHome\network\admin\listener.ora
Find the TNS entry for the gateway and change the program this way:
PROGRAM=g4drsrvd
Save the file and exit. Next, restart the Oracle Net Listener:
> lsnrctl start
Edit the gateway's initsid.ora file with any text editor:
> notepad C:\Oracle\GTWHome\tg4drda\admin\initsid.ora
Set the following parameters:
TRACE_LEVEL=255 ORACLE_DRDA_TCTL=debug.tctl
Note:
Refer to Appendix C, "DRDA-Specific Parameters" for descriptions of those parameters.You may, as an option, add the LOG_DESTINATION parameter, but it is not required. If you specify a LOG_DESTINATION, then you may specify just the file name (for example, drda.trc), or you may specify a fully qualified path name. If you specify a LOG_DESTINATION with just the file name, then the log will be written to the log directory (ORACLE_HOME\tg4drda\trace) of the gateway. If you do not specify a LOG_DESTINATION, then a unique log file in a default format will be generated. The log file name will be of the form:
gatewaysid_tid.trc
Where:
gateway sid is the SID of the gateway.
tid is the thread identifier (TID) of the gateway service.
An example log file name would be:
drdahoa1_3875.trc
When searching for the SQL statements which are passed to the DRDA Server, look for the strings '*** HGAPARS ***' and '*** HGAXMSQL ***'. The string after HGAPARS will be the incoming statement from the Oracle Database 10g RDBMS. The string after HGAXMSQL will be the outgoing statement after any date substitution is done. This is the actual SQL statement which will be given to the DRDA Server.
When you have finished developing your application, revert the PROGRAM= value in the listener.ora file to its previous value and reload the listener to use the production gateway again. You should also comment out the trace parameters in the gateway initialization files.
