@BeforeClass
  public static void setUpBeforeClass() throws Exception {
    KDC = TEST_UTIL.setupMiniKdc(KEYTAB_FILE);
    SERVER_PRINCIPAL = "server/" + HOST;
    SERVER_PRINCIPAL2 = "server2/" + HOST;
    CLIENT_PRINCIPAL = "client";
    KDC.createPrincipal(KEYTAB_FILE, CLIENT_PRINCIPAL, SERVER_PRINCIPAL, SERVER_PRINCIPAL2);
    TEST_UTIL.getConfiguration().setInt("hbase.security.relogin.maxbackoff", 1);
    TEST_UTIL.getConfiguration().setInt("hbase.security.relogin.maxretries", 0);
    TEST_UTIL.getConfiguration().setInt(RpcClient.FAILED_SERVER_EXPIRY_KEY, 10);
  }
Test secure client connecting to a non secure server, where we have multiple server principal
candidates for a rpc service. See HBASE-28321.
hbase-server/src/test/java/org/apache/hadoop/hbase/security/TestMultipleServerPrincipalsFallbackToSimple.java