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Chapter 9. Accessing relational databases from WebSphere 379

There are two transaction scopes in WebSphere Application Server:

 Global transaction

 Local transaction containment (LTC)

9.9.2 Configuring Shared and Unshared Connections

This section provides information about configuring shared and unshared connections:

 Resource Reference: The resource reference can be used to configure connection

sharing for connection factory or data source. Example 9-1 shows how to configure

shared connections for a data source using the resource reference.

Example 9-1 Shared connections for a data source

<resource-ref>

<jndi-name>jdbc/Acount</jndi-name>

<authentication-alias>Alias1</authentication-alias>

<interface>javax.sql.DataSource</interface>

<authentication>Container</authentication>

<sharing-scope>Shareable</sharing-scope>

<id>resourceRef</id>

</resource-ref>

 Connection pool Custom properties: Custom properties, defaultConnectionTypeOverride

and globalConnectionTypeOverride can be used to control connection sharing for a

particular connection factory or data source:

– defaultConnectionTypeOverride

Changes the default sharing value for a connection pool. The value configured through

resource references takes precedence over this property.

– globalConnectionTypeOverride:

The value takes precedence over all of the other connection sharing settings for

connection factory or data source.

More information about Connection pool Custom properties is in the information center at the

following website:

http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/index.jsp?topic=%2Fcom.ibm.webspher

e.express.iseries.doc%2Fae%2Frdat_conpoolcustprops.html

9.10 Troubleshooting database access problems

This section describes ways to troubleshoot database access problems with WebSphere

Application server. The following topics are covered:

 Enabling JDBC tracing for database problems

 Enabling ConnLeakLogic

 Dumping connection pool information using wsadmin

 Tool to debug Database Access problems

380 WebSphere Application Server V8.5 Administration and Configuration Guide for the Full Profile

9.10.1 Enabling JDBC tracing for database problems

If the problem can be reproduced easily, enable a WebSphere Application Server trace. To

enable the tracing:

1. Click Troubleshooting  Logs and Trace in the Application Server administrative

console.

2. In the Logging and Tracing, select your Server  Diagnostic Trace.

3. Go to Trace Output  File. Accept the defaults.

4. Click OK.

5. Select change the Log Detail Levels.

6. Enter the following strings depending on your connection type:

– Connecting to a database enter:

*info:

WAS.j2c=all:

RRA=all:

Transaction=all

– Connecting to an enterprise information system enter:

*info:

WAS.j2c=all:

com.ibm.connector2.*all:

Transaction=all

– Connecting to a messaging system enter:

*info:

WAS.j2c=all:

Messaging=all:

JMSApi=all:

Transaction=all

7. Save your configuration and then click OK.

8. Restart the Application Server.

9. Reproduce the problem.

10.Send the resulting trace output file to IBM support for further analysis.

9.10.2 Enabling ConnLeakLogic

Connection pools get exhausted due to a variety of reasons, and ConnLeakLogic can be

enabled to identify the application code holding the connections for long durations. It is

recommended to enable a ‘Runtime’ trace instead of a ‘Configuration’ trace, which allows the

trace to be disabled after the diagnostic data is retrieved from the server. To enable the

ConnLeakLogic:

1. Start the application server.

2. Enable a Runtime trace immediately after starting the server:

a. Click Troubleshooting  Logs and Trace in the WebSphere Application Server

administrative console.

b. Select the link for your server.

c. Click Diagnostic Trace.

Chapter 9. Accessing relational databases from WebSphere 381

d. Click Runtime tab.

e. Click Change Log Level Details.

f. Click the Runtime tab.

g. In the Trace Specification field, enter ConnLeakLogic=all.

h. Click OK.

9.10.3 Dumping connection pool information using wsadmin

For collecting diagnostic data you can look at the SystemOut.log while the system is running.

If you see the J2CA0045E error message in SystemOut.log, invoke wsadmin to dump the pool

contents of the data source.

Use one of the following commands to dump the content of the connection pool:

 C:\IBM\WebSphere\bin>wsadmin -c “$AdminControl invoke [$AdminControl queryNames

\”*:name=<INSERT DISPLAY NAME OF DATASOURCE HERE>,process=<SERVER

NAME>,node=<NODE NAME>,j2eeType=JDBCDataSource,*\”] showPoolContents” -user

<adminuserid> -password <adminpw>

 C:\IBM\WebSphere\bin>wsadmin>set ds [$AdminControl queryNames “*:name=<INSERT

DISPLAY NAME OF DATASOURCE HERE>,process=<SERVER NAME>, node=<NODE

NAME>,j2eeType=JDBCDataSource,*”]

wsadmin>$AdminControl invoke $ds showPoolContents

9.10.4 Tool to debug Database Access problems

For debugging database access problems, you can use the IBM Database Connection Pool

Analyzer. This tool finds JDBC connection leaks and helps to resolve JDBC connection pool

problems. The tool performs the following functions:

 Analysis of JDBC data source

 Java stack trace view of getConnection method

 JDBC connection chart view

 Analysis of JDBC connection pool configuration

You can download the IBM Database Connection Pool Analyzer from the following website:

https://www.ibm.com/developerworks/mydeveloperworks/groups/service/html/communityv

iew?communityUuid=f324412c-747c-42b9-8a70-a4d54e5f0e03

Note: Ensure that you enabled the trace immediately after the server is started before any

connections are obtained from the connection pool.

A trace.log is created that contains similar content as the SystemOut.log. It does not log

ongoing messages, such as a WAS.j2c trace, and it causes only slight performance

impact.

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