Buscador de texto tipo google en MySQL

Se puede usar el feature de FULLTEXT Indexing and Searching de mysql:

http://www.petefreitag.com/item/477.cfm

Pool de threads nativo en java

LinkedBlockingQueue queue = new LinkedBlockingQueue();
pool = new ThreadPoolExecutor(corePoolSize,maximumPoolSize,keepAliveTimeMs,TimeUnit.MILLISECONDS,queue);

CandidateFetcher fetcher = new CandidateFetcher(candidate); //implements Runnable
pool.execute(fetcher);

while(pool.getActiveCount()>0){
log.info("pool.getActiveCount(): "+pool.getActiveCount()+", waitUntilAllFetchesAreDone, go to sleep");
Thread.sleep(5000);
}
log.info("pool.getActiveCount(): 0, terminaron todos");