Network Deployment (Distributed operating systems), v8.0 > Reference > Troubleshoot tips

Data access problems

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

New feature: Beginning in WAS v8.0 you can configure the server to use the HPEL log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files or native z/OS logging facilities. If you are using HPEL, you can access all of your log and trace information using the LogViewer command-line tool from your server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL.New feature:

The following steps help you quickly isolate connectivity problems.

1. Browse the log files of the application server for clues.

   See the topic, Viewing JVM logs. By default, these files are WAS_HOME/server_name

   SystemErr.log and SystemOut.log.

   New feature: Beginning in WAS v8.0 you can configure the server to use the HPEL log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files or native z/OS logging facilities. If you are using HPEL, you can access all of your log and trace information using the LogViewer command-line tool from your server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL.New feature:

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 Java Naming and Directory Interface (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 the WAS product support page. (Find the link at the end of this article.) In the Search Support field, type a database vendor name among your search terms. Select Solve a problem, then click Search.

Remember that you 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:

• Oracle
• DB2
• SQL Server
• Apache Derby
• Sybase
• General data access problems

General data access problems

• An exception "IllegalConnectionUseException" occurs
• WTRN0062E: An illegal attempt to enlist multiple one phase capable resources has occurred.
• ConnectionWaitTimeoutException.
• com.ibm.websphere.ce.cm.StaleConnectionException: [IBM][CLI Driver] SQL1013N The database alias name or database name "NULL" could not be found. SQLSTATE=42705
• java.sql.SQLException: java.lang.UnsatisfiedLinkError:
• "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.
• java.lang.UnsatisfiedLinkError:xaConnect exception when attempting a database operation
• "J2CA0114W: No container-managed authentication alias found for connection factory or data source datasource" when attempting a database operation
• An error is thrown if you use the ws_ant command to perform the database customization for Structured Query Language in Java on HP platforms
• Container-managed persistence (CMP) cannot successfully obtain the database access function as defined.

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 programming 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:

• An attempt was made to share a one-phase connection but the getConnection calls do not all use the same connection properties; such as the AccessIntent property.
• An attempt was made to have more than one unshareable connection participate in a global transaction, when the data source is not an XA resource.
• An attempt was made to have a one-phase resource participate in a global transaction while an XA resource or another one-phase resource has already participated in this global transaction. The following information might help identify why the error condition is occurring:

  • If you are using a non-XA data source and you are expecting to share a connection, set all of the relevant resource-refs to shareable. If you do not use a resource-ref, the default is set to unshareable connections.
  • Your connection is not shared if you do not use the same connection properties, such as IsolationLevel or AccessIntent, on each connection request.
  • Your connections might not be shared if you are using CMP beans that might be using different AccessIntent settings.

    To learn more about CMP beans sharing a connection with non-CMP components, see theinformation on extensions to data access APIs.

To correct this error:

• Check what your client code passes in with its getConnection requests, to ensure that they are consistent with each other.
• Check the connection sharing scope from the resource binding, using an assembly tool. See the topic, Assembly tools.

  • If you are running an unshareable connection scope, verify that your data source is an XA data source.

  • If you are running a shareable connection scope, verify that all connection properties, including AccessIntent, are shareable.

• Check the JDBC provider implementation class from the Manage JDBC resource panel of the admin console to ensure that it is a class that supports XA-type transactions.

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, some possible causes are:

• The maximum number of connections for a given pool is set too low. The demand for concurrent use of connections is greater than the configured maximum value for the connection pool. One indication that this situation is the problem is that you receive these exceptions regularly, but your CPU utilization is not high. This exception indicates that there are too few connections available to keep the threads in the server busy.
• Connection Wait Time is set too low. Current demand for connections is high enough such that sometimes there is not an available connection for short periods of time. If your connection wait timeout value is too low, you might timeout shortly before a user returns a connection back to the pool. Adjusting the connection wait time can give you some relief. One indication of this problem is that you use close to the maximum number of connections for an extended period and receiving this error regularly.
• You are not closing some connections or you are returning connections back to the pool at a slow rate. This situation can happen when using unshareable connections, when you forget to close them, or you close them long after you are finished with them, keeping the connection from returning to the pool for reuse. The pool soon becomes empty and all applications get ConnectionWaitTimeoutExceptions. One indication of this problem is you run out of connections in the connection pool and you receive this error on most requests.
• You are driving more load than the server or backend system have resources to handle. In this case determine which resources you need more of and upgrade configurations or hardware to address the need. One indication of this problem is that the application server or the database server processor is nearly 100% busy.

To correct these problems, either:

• Modify an application to use fewer connections
• Properly close the connections.
• Change the pool settings of MaxConnections or ConnnectionWaitTimeout.
• Adjust resources and their configurations.

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 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 you can correct the LIBPATH variable to include the missing directory, either in the.profile of the account from which WAS is started, or by adding a statement in a .sh file which then starts 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 supports 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:

• WAS Programming Model Extensions (PME) is installed. PME is included in the Application Server Integration Server product.
• The Additional Integration Server Extensions option is enabled when PME is installed. If you perform a typical installation, this function is enabled by default. If you perform a custom installation, you can disable this function, which disables last participant support.
• The application enlisting the one-phase resource is deployed with the Accept heuristic hazard option enabled. This deployment is done with an assembly tool.

This problem has two main causes:

• The most common cause is that the JDBC driver that supports connectivity to the database is missing, or is not the correct version. Another common cause is the native libraries which support the driver are on the system path.

  • To resolve this problem on a Windows platform, verify that the JDBC driver JAR file is on the system PATH environment variable:

    • If you are using DB2, verify that at least the DB2 client product has been installed on the WebSphere host
      • On DB2 version 7.2 or earlier, the file where the client product is installed on the WAS is db2java.zip. Verify that the usejdbc2.bat program has been executed after the database install and after any upgrade to the database product.
      • On DB2 version 8.1 or later, use the DB2 Universal JDBC Provider Driver when defining a JDBC provider in WAS. The driver file is db2jcc.jar. If you use the type 2 (default) option, verify that at least the DB2 client product is installed on the WAS host. If you specify the type 4 option, the DB2 client does not need to be installed, but the file db2jcc.jar still must be present.

        When specifying the location of the driver file, IBM recommends to that you specify the path and file name of the target DB2 installation, rather than copying the file to a local directory, if possible. Otherwise, you might be exposed to problems if the target DB2 installation is upgraded and the driver used by WAS is not.

  • On operating systems such as AIX or Linux, ensure that any native libraries required to support the database client of your database product are specified in the LD_LIBRARY_PATH environment variable in the profile of the account under which WAS starts.

    If you are using DB2 The native library is libdb2jdbc.so. The best way to ensure that this library is accessed correctly by WebSphere is to call the db2profile script supplied with DB2 from the .profile script of the account (such as "root") under which WebSphere runs.

    • If you are using DB2 version 7.2 or earlier, ensure that the usejdbc2,script provided with DB2 is called from the profile of the account under which WAS is launched.

    • If you are using DB2 version 8.1 or later, see the previous instructions for the Windows operating system.

• If the database manager is DB2, you can choose the option to create a 64-bit instance.  Sometimes a 64-bit configuration is not supported. If this has happened, remove the database instance and create one with the default 32-bit setting.

  If you are using the Universal JDBC T2 driver, WAS does support interaction with a DB2 UDB 64-bit server, but it must be through a DB2 UDB 32-bit client. The WAS environment (CLASSPATH, and so on) must use the 32-bit client code to ensure correct function.

  With a Universal JDBC T4 driver, you do not need the 32-bit DB2 client. You need only configure the class path to include db2jcc.jar and its license files in the WAS environment.

  For general help in configuring JDBC drivers and data sources in WAS, see the topic, Accessing data from applications.

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

This error might occur in the SystemOut.log file 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 you use the ws_ant command to perform the database customization for Structured Query Language in Java on HP platforms

If you use the ws_ant command to perform the database customization for Structured Query Language in Java (SQLJ) on HP platforms, you 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 your databases were created using the HP default character set. The Java Common Client (JCC) driver depends on the software development kit (SDK) to perform the code page conversions. The SDK shipped with this product, however, does not support the HP default code page.

We must set your 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 (CMP) 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:

• Add an enterprise bean custom finder method; a NullPointerException exception is created.
• Update an enterprise bean custom finder method; the new SQL statement does not run.
• Change schema mapping; the new SQL statement does not run.

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

Related

Data access problems for Oracle data sources
Data access problems for DB2 databases
Data access problems for Microsoft SQL Server data sources
Data access problems for Apache Derby databases
Data access problems for Sybase data sources
Troubleshoot help from IBM
Assembly tools
Use HPEL to troubleshoot applications
View JVM logs
Task overview: Accessing data from applications

Related

Extensions to data access APIs

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