If an exception is thrown from within the change indexer, the reindex program shows a stack trace. In the case of an error when using the Solr index, it does not exit and continues running, while showing debug messages "Got ping response for sessionid", but not doing anything else. Catch exceptions in the indexer and exit with a fatal error message. Change-Id: Ief41eccc0d3fe9c5592782b51afa66c0c3150886