Data access problems


 

+

Search Tips   |   Advanced Search

 

WAS diagnostic tools provide services to help troubleshoot database connection problems. Additionally, the IBM Web site provides flexible searching capabilities for finding documented solutions to database-specific connection problems.

The following steps help you quickly isolate connectivity problems.

  1. Browse the log files of the appserver for clues.

    See the topic, Viewing JVM logs. By default, these files are APP_ROOT/server_name/SystemErr.log and SystemOut.log.

  2. Browse the Helper Class property of the data source to verify that it is correct and that it is on the WAS class path. Mysterious errors or behavior might result from a missing or misnamed Helper Class name. If WAS cannot load the specified class, it uses a default helper class that might not function correctly with your database manager.

  3. Verify that the JNDI name of the data source matches the name used by the client attempting to access it. If error messages indicate that the problem might be naming-related, such as referring to the name server or naming service, or including error IDs beginning with NMSV, look at the topics, Naming related problems and Troubleshooting the naming service component.

  4. Enable tracing for the resource adapter using the trace specification, RRA=all=enabled. Follow the instructions for dumping and browsing the trace output, to narrow the origin of the problem. See the topic, Enabling tracing.

For a comprehensive list of database-specific troubleshooting tips, see WAS v7 support page. (Find the link at the end of this article.) In the Search Support field, type a database vendor name among the search terms. Select Solve a problem, then click Search.

Remember that we can always find Support references in the topic, Troubleshooting help from IBM, in this information center.

Currently this information center provides a limited number of troubleshooting tips for the following databases:

 

General data access problems

 

IllegalConnectionUseException

This error can occur because a connection obtained from a WAS40DataSource is being used on more than one thread. This usage violates the J2EE 1.3 programming model, and an exception generates when it is detected on the server. This problem occurs for users accessing a data source through servlets or bean-managed persistence (BMP) enterprise beans.

To confirm this problem, examine the code for connection sharing. Code can inadvertently cause sharing by not following the model recommendations, for example by storing a connection in an instance variable in a servlet, which can cause use of the connection on multiple threads at the same time.

 

WTRN0062E: An illegal attempt to enlist multiple one phase capable resources has occurred

This error can occur because:

To correct this error:

 

ConnectionWaitTimeoutException accessing a data source or resource adapter

If the application receives exceptions like a com.ibm.websphere.ce.cm.ConnectionWaitTimeoutException or com.ibm.websphere.ce.j2c.ConnectionWaitTimeoutException when attempting to access a WAS data source or JCA-compliant resource adapter, respectively, some possible causes are:

To correct these problems, either:

 

com.ibm.websphere.ce.cm.StaleConnectionException: [IBM][CLI Driver] SQL1013N The database alias name or database name "NULL" could not be found. SQLSTATE=42705

This error occurs when a data source is defined but the databaseName attribute and the corresponding value are not added to the custom properties panel. To add the databaseName property:

  1. Click Resources>Manage JDBC Providers link in the admin console.

  2. Select the JDBC provider that supports the problem data source.

  3. Select Data Sources and then select the problem data source.

  4. Under Additional properties click Custom Properties.

  5. Select the databaseName property, or add one if it does not exist, and enter the actual database name as the value.

  6. Click Apply or OK, and then click Save from the action bar.

  7. Access the data source again.

 

java.sql.SQLException: java.lang.UnsatisfiedLinkError:

This error indicates that the directory containing the binary libraries which support a database are not included in the LIBPATH environment variable for the environment in which the WAS starts.

The path containing the DBM vendor libraries vary by dbm. One way to find them is by scanning for the missing library specified in the error message. Then we can correct the LIBPATH variable to include the missing directory, either in the .profile of the account from which WAS is executed, or by adding a statement in a .sh file which then executes the startServer program.

 

"J2CA0030E: Method enlist caught java.lang.IllegalStateException" wrapped in error "WTRN0063E: An illegal attempt to enlist a one phase capable resource with existing two phase capable resources has occurred" when attempting to execute a transaction.

This error can occur when last participant support is missing or disabled. last participant support allows a one-phase capable resource and a two-phase capable resource to enlist within the same transaction. Last participant support is only available if the following are true:

This problem has two main causes:

 

"J2CA0114W: No container-managed authentication alias found for connection factory or datasource datasource" when attempting a database operation

This error might occur in SystemOut.log when you run an application to access a data source after creating the data source using JACL script. The error message occurs because the JACL script did not set container-managed authentication alias for CMP connection factory. The JACL is missing the following line:

$AdminConfig create MappingModule $cmpConnectorFactory "{mappingConfigAlias DefaultPrincipalMapping} {authDataAlias $authDataAlias}

To correct this problem, add the missing line to the JACL script and run the script again. See the topic, Example: Creating a JDBC provider and data source using Java Management Extensions API and the scripting tool, for a sample JACL script.

 

An error is thrown if we use the ws_ant command to perform the database customization for SQL in Java on HP platforms

If we use the ws_ant command to perform the database customization for SQL in Java (SQLJ) on HP platforms, we can receive an error similar to the following:

[java] [ibm][db2][jcc][sqlj]
[java] [ibm][db2][jcc][sqlj] Begin Customization
[java] [ibm][db2][jcc][sqlj] encoding not supported!!

The cause of this error might be that the databases were created using the HP default character set. The Java Common Client (JCC) driver depends on the SDK to perform the codepage conversions. The SDK shipped with this product, however, does not support the HP default codepage.

You need to set the LANG to the ISO locale before creating the databases. It should be similar to the following:

export LANG=en_US.iso88591

Refer to the IBM support site for Information Management software to access the latest technotes for DB2.

 

Container-managed persistence cannot successfully obtain the database access function as defined.

When WAS is caching certain generated code that is accessed in the database on the connection factory, and if any changes in the JAR file require regeneration of the database access, the changes are not effective until you stop and restart the server.

Examples of when this failure might occur include:

In summary, if we add or update an enterprise bean that contains a custom finder method, stop and then restart the server.



Subtopics


Data access problems - Oracle data source
Data access problems - DB2 database
Data access problems - Microsoft SQL Server data source
Data access problems - Apache Derby database
Data access problems - Sybase data source

 

Related concepts


Troubleshooting help from IBM
Assembly tools

 

Related tasks


Example: Using IBM extended APIs to share connections between CMP beans and BMP beans
Set up the error log
View JVM logs
Task overview: Accessing data from applications

 

Related


Extensions to data access APIs