@Test
  public void testManagersWithLargeGroups() throws Exception {
    StringBuilder stringBuilder = new StringBuilder(80000);
    boolean first = true;
    // create 8000 10-byte group names
    for (int thousands = 1; thousands < 9; thousands++) {
      for (int group = 0; group < 1000; group++) {
        if (!first) {
          stringBuilder.append(',');
        }
        first = false;
        stringBuilder.append(String.format("%1$02d%2$08d", thousands, group));
      }
    }
    List<String> result = doTestMultipleManagersInSameProcessWithGroups(stringBuilder.toString());
    assertEquals(8000, result.size());
    for (String group : result) {
      assertEquals(10, group.length());
    }
  }
Ensure that a large membership group doesn't cause communication issues
geode-core/src/integrationTest/java/org/apache/geode/distributed/internal/membership/MembershipJUnitTest.java