Select statement after Update statement under autocommit with RAC

Question

Hi,
I've met a problem when developing my application with 10g RAC (3 machines). I am using open jdk 1.6.0 on linux platform with kernel release 2.6.18-128.e15PAE, my app using spring with oracledatasource to establish the database connection with autocommit. The situation as below:
my application sends SMPP requests and receives SMPP responses, when receiving SMPP responses, my app update the response details to related record in DB. For some concatenated messages, my app need to check whether all responses of the related concatenated message are received, if all received, my app update the final status of the message.
it is found that for some concatenated messages, all responses are received successfully, i.e. can be found in the database that the details of the responses are updated, however the final status of the message is not updated as expected. After further investigations to the database records and application logs, those cannot be updated with response returning almost at the same second, however they are manipulated one by one, not multi-thread. From the log of my app, it shown the dealing of the second response is started in the same second when the dealing of the first response is completed. It seems like when dealing the second response, it cannot "see" the first response is updated such that both responses find the message is not completed.
Wonder under what condition would this happen? my db config as below:
<bean id="dataSource" class="oracle.jdbc.pool.OracleDataSource" destroy-method="close">
<property name="driverType" value="oracle.jdbc.driver.OracleDriver" />
<property name="URL" value="jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dbhost1)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=dbhost2)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=dbhost3)(PORT=1521))(LOAD_BALANCE=yes)(CONNECT_DATA=(SERVICE_NAME=ha_bss)(SERVER=DEDICATED)))" />
<property name="user" value="dbuser" />
<property name="password" value="dbpassword" />
<property name="connectionCachingEnabled" value="true" />
<property name="connectionCacheProperties">
<props merge="default">
<prop key="InitialLimit">10</prop>
<prop key="MinLimit">10</prop>
<prop key="MaxLimit">2000</prop>
<prop key="AbandonedConnectionTimeout">0</prop>
<prop key="ConnectionWaitTimeout">120</prop>
<prop key="validate-connection">true</prop>
<prop key="validate-connection-statement">SELECT SYSDATE FROM DUAL</prop>
<prop key="factory-class">oracle.jdbc.pool.OracleDataSourceFactory</prop>
</props>
</property>
<property name="ONSConfiguration" value="nodes=dbhost1:6200,dbhost2:6200,dbhost3:6200"/>
<property name="fastConnectionFailoverEnabled" value="true"/>
</bean>
thanks

Answer 1

This is not likely to be a JDBC issue at all. It is likely that separate connections are being used
for the separate threads, and they may be to different RAC nodes. You must configure your
DBMS so there is zero latency between the nodes, else there may be some delay between
when one node changes data and another can see it.
HTH,
Joe