code: @CacheEntryModified
     public void cacheEntryModified(CacheEntryModifiedEvent<Serializable, Object> event)
     {
        if (!event.isPre() && event.getKey().equals(updateKey))
        {
           Object value = event.getValue();
           localUpdateInProgress = value != null ? (Boolean)value : false;
  
           for (IndexUpdateMonitorListener listener : listeners)
           {
              listener.onUpdateInProgressChange(localUpdateInProgress);
           }
        }
     }
docs: Method will be invoked when a cache entry has been modified only in READ_ONLY mode.
  
  @param event
  CacheEntryModifiedEvent