[CAMEL-19081] Start a route with aggregation fails due to NPE in AggregateProcessor

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.20.1
• Fix Version/s: 3.14.8, 3.18.6, 3.20.3, 3.21.0, 4.0-M3, 4.0.0
• Component/s: camel-core
• Estimated Complexity: Unknown
• Assignee: Radovan Netuka
• Reporter: Sydney Henrard
• Created: 21/Feb/23 18:01
• Updated: 17/Mar/23 15:57
• Resolved: 17/Mar/23 15:57

Description

In my application I have a route with an aggregation using an aggregation repository ClusteredJdbcAggregationRepository and completionTimeout. This route is part of a micro service that can be scaled. From time to time, the micro service does not start due to a NPE:

Caused by: java.lang.NullPointerException: Cannot invoke "org.apache.camel.Exchange.getProperty(org.apache.camel.ExchangePropertyKey, Object, java.lang.Class)" because "exchange" is null         at org.apache.camel.processor.aggregate.AggregateProcessor.restoreTimeoutMapFromAggregationRepository(AggregateProcessor.java:920) ~[camel-core-processor-3.20.1.jar:3.20.1]  

In my case the exchange is null because it has already been processed by one of the micro service instance.
 The relevant code is in https://github.com/apache/camel/blob/camel-3.20.1/core/camel-core-processor/src/main/java/org/apache/camel/processor/aggregate/AggregateProcessor.java#L920

for (String key : keys) {     
    Exchange exchange = aggregationRepository.get(camelContext, key);     // grab the timeout value     
    long timeout = exchange.getProperty(ExchangePropertyKey.AGGREGATED_TIMEOUT, 0L, long.class);

 
The null check is missing. It's not a problem when aggregation repository is not shared among instance like LevelDB, but it is when it's shared like JDBC.

Issue Links

• links to: GitHub Pull Request #9569