public void setIndexMaintenanceSynchronous(boolean synchronous) {
    regionAttributes.indexMaintenanceSynchronous = synchronous;
    regionAttributes.setHasIndexMaintenanceSynchronous(true);
  }
Set how indexes on the region should be maintained. It will be either synchronous or
asynchronous. Default is true.

@param synchronous boolean specifying if index maintenance on the region should be synchronous
       (true) or asynchronous (false)
geode-core/src/main/java/org/apache/geode/cache/AttributesFactory.java