Spring boot, multi-tenet, multi-module, #Transactional , parallelStream - spring

Question

I am trying to insert some 50k records into db. We have used AbstractRoutingDataSource which resolve Datasource using TenantContext which is a utility class and has a private static final ThreadLocal CURRENT_TENANT = new ThreadLocal<>();
when I am using parallel stream or if I am trying to make the method #Async I am getting the below error
Code:
.parallelStream()
.forEach(row -> {
TenantContext.setCurrentTenant(centerCd);
someDao.insert(row);
});
Error:
org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.lang.IllegalStateException: Cannot determine target DataSource for lookup key [null]
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:305)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:378)
at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:474)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:289)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.interceptor.AsyncExecutionInterceptor.lambda$invoke$0(AsyncExecutionInterceptor.java:115)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: Cannot determine target DataSource for lookup key [null]
at org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource.determineTargetDataSource(AbstractRoutingDataSource.java:207)
at org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource.getConnection(AbstractRoutingDataSource.java:169)
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:262)
... 10 common frames omitted

Answer 1

It works exactly like you described: your TenantContext is exactly ThreadLocal and exists in a thread, which is initiated either by parallelStream() or Async method. (in reality, the call inside of the Async or forEach method is a run from Runnable)
The data source is attempted to be injected/resolved at start of the thread: because your transaction have to be started at the thread creation, before your Runnable gets into a run method. And at this moment of time you haven't yet specified your tenant, call TenantContext.setCurrentTenant(centerCd) is performed later in a run method implementation.
I would suggest applying such structure to your code:
class TenantAwareThread extends Thread {
public TenantAwareThread(Runnable target, TenantData tenantData) {
super(target);
TenantContext.setCurrentTenant(tenantData);
}
}
#Autowired
TaskExecutor executor;
void startTask(TenantData tenantData, RowData row) {
executor.execute(
new TenantAwareThread(() -> {
someDao.insert(row);
},
tenantData));
}
You create a new thread type which is aware of tenant data from the very beginning. And simply wraps your executions into such thread.