@Override
            public void afterUpdate(EntryEvent event) {
              getCache().getLogger().info("afterUpdate invoked with " + event);
              killSender(event);
            }
test putIfAbsent with failover & retry. This is bugs 42559 and 43640
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ConcurrentMapOpsDUnitTest.java