// restart datanodes on the same ports that they currently use
assertTrue(cluster.restartDataNodes(true));
cluster.waitActive();
assertEquals(numDataNodes, cluster.getDataNodes().size());
cluster.shutdownNameNode(0);
// confirm tokens cached in in1 are still valid
lblocks = DFSTestUtil.getAllBlocks(in1);
for (LocatedBlock blk : lblocks) {
assertFalse(SecurityTestUtil.isBlockTokenExpired(blk.getBlockToken()));