Critical Description
ToolRunner class is not thread-safe because it uses GenericOptionsParser. The constructor of GenericOptionsParser uses 'OptionBuilder' which is a singleton class that uses instance variables. In other words, OptionBuilder is NOT thread safe. As a result, when multiple Hadoop jobs are triggered simultaneously using ToolRunner they end up stepping on each other.
The easiest way to fix it is by making 'buildGeneralOptions' synchronized in GenericOptionsParser.
private static synchronized Options buildGeneralOptions(Options opts) {
If this seems like a correct way of fixing this, either we can provide a patch or someone can quickly fix it. Thanks.
- Ajay Chitre
achitre@cisco.com
Virendra Singh
virsingh@cisco.com