public static Map<DistributedMember, Set<PersistentID>> send(DistributionManager dm) {
    Set recipients = dm.getOtherDistributionManagerIds();
    CompactRequest request = new CompactRequest();
    request.setRecipients(recipients);

    CompactReplyProcessor replyProcessor = new CompactReplyProcessor(dm, recipients);
    request.msgId = replyProcessor.getProcessorId();
    dm.putOutgoing(request);

    request.setSender(dm.getDistributionManagerId());
    request.process((ClusterDistributionManager) dm);

    try {
      replyProcessor.waitForReplies();
    } catch (ReplyException e) {
      if (!(e.getCause() instanceof CancelException)) {
        throw e;
      }
    } catch (InterruptedException e) {
      logger.warn(e);
    }

    return replyProcessor.results;
  }
An instruction to all members with cache that they should compact their disk stores.
geode-core/src/main/java/org/apache/geode/internal/admin/remote/CompactRequest.java