@Override
        public void run() {
          while (!done.get()) {
            try {
              HTU.loadNumericRows(table, fam, key.get(), key.get() + 1000);
              key.addAndGet(1000);
            } catch (Throwable e) {
              ex.compareAndSet(null, e);
            }
          }
        }
Tests the case where there are 3 region replicas and the primary is continuously accepting new
writes while one of the secondaries is killed. Verification is done for both of the secondary
replicas.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionReplicaFailover.java