Ggtcf

I am writing a Camel integration that can consume an arbitrary number of queries and execute those against an arbitrary number of databases.

The route starts by getting all queries located in a folder and then uses a splitter to iterate over them in order:

from("quartz2:quartzInitializer?cron=sync.cron")
 .routeId("quartzInitializer")
 .bean(QueryHandler.class, "getQueries")
 .split(exchangeProperty(QueryHandler.Properties.QUERIES))
 .setProperty(Properties.CURRENT_QUERY, simple("body"))
 .to("direct:executeSingleQuery")
 .end();

In the above snippet, the property QueryHandler.Properties.QUERIES contains two query file locations:

config/sql/1__select_stat_machine.sql
config/sql/2__select_stat_session.sql

Next, I send the location of the iterated query and construct a recipient list from it:

from("direct:executeSingleQuery")
 .routeId("executeSingleQuery")
 .bean(DataSourceHandler.class, "createEndpointsWithQuery")
 .recipientList(exchangeProperty(DataSourceHandler.Properties.QUERY_RECIPIENTS))
 .parallelProcessing()
 .log(LoggingLevel.INFO, String.format("Calling $in.header.%s", Exchange.RECIPIENT_LIST_ENDPOINT));

In the above snippet, the parameter DataSourceHandler.Properties.QUERY_RECIPIENTS contains two recipients:

sql:file:config/sql/1__select_stat_machine.sql?dataSource=datasource3&outputHeader=resultset
sql:file:config/sql/1__select_stat_machine.sql?dataSource=datasource2&outputHeader=resultset

However, when I run this, only one of the recipients are called, in this case only datasource2, which was at index 1 in the list passed to the recipientList:

Calling sql://file:config/sql/1__select_stat_machine.sql?dataSource=datasource2&outputHeader=resultset
Calling sql://file:config/sql/2__select_stat_session.sql?dataSource=datasource2&outputHeader=resultset

I can't for the life of me figure out what I'm doing wrong. Am I missing an end() somewhere? Is my splitter at fault, or is it my recipient list?

.recipientList(exchangeProperty(...))
 .log(LoggingLevel.INFO, String.format("Calling $in.header.%s", Exchange.RECIPIENT_LIST_ENDPOINT));

Your are putting the log statement in the wrong place.
Basically the way you have modelled your route is:
"Please send the messages to all recipients, and AFTER this, print a message". The fact is that after looping through the list of recipients, Camel variable holds the URI of the LAST recipient.

It is more obvious in Spring DSL:

What your Camel route is doing:

<recipientList>
 <header>...</header> 
</recipientList>
<log message="Done"/>

versus what you think Camel is doing:

<recipientList>
 <header>...</header>
 <log message="Done"/> 
</recipientList>