code: private void closeOutgoingSockets() throws ClientException {
  
          SocketOperator op = new SocketOperator() {
                  public void operate(SocketBox sb) throws Exception {
                      if (((ManagedSocketBox) sb).isReusable()) {
                          Socket s = sb.getSocket();
                          if (s != null) {
                              // write the closing Eblock and close the socket
                              EBlockImageDCWriter.close(
                                    new DataOutputStream(s.getOutputStream()));
                          }
                      }
                  }
         };
  
          try {
              socketPool.applyToAll(op);
          } catch (IOException e) {
              // ignore - sometimes server might close the socket
          } catch (Exception e) {
              ClientException ce =
                  new ClientException(ClientException.SOCKET_OP_FAILED);
              ce.setRootCause(e);
              throw ce;
          }
      }
docs: All sockets opened when this server was active
  should send a special EBlock header before closing.