In rare cases, due to a problem in the Java 5 JDK, if you are using multiplexed routing under extremely heavy load, Search may throw a Null Pointer Exception.
Multiplexed and serialized are the options used by Search routing to optimize handling of multi-partition indexes. If using the multiplexed strategy (the default for a multi-partition index), routing addresses all Search engines simultaneously. If using the serialized strategy, routing contacts engines one after another.
To change your routing strategy to serialized, create a RoutingSearchService.properties file in /atg/servername/localconfig/atg/search/routing with this line:
strategyType=serialized
Then rebuild and redeploy your ATG application EAR file.
