private MemoryUtil() {
    }

    /**
     * Gets a formatted memory usage log string.
     *
     * @return formatted memory usage information
     */
    public static String getMemoryUsageLog() {
        final Runtime runtime = Runtime.getRuntime();
        final long freeBytes = runtime.freeMemory();
        final long maxBytes = runtime.maxMemory();
        final long totalBytes = runtime.totalMemory();

                            MemoryUtil.getMemoryUsageLog());
                } else {
                    logger.info("Sent {} documents (send={}ms, {})", docList.size(), systemHelper.getCurrentTimeAsLong() - execTime,
                            MemoryUtil.getMemoryUsageLog());
                }
            }
        } finally {
            docList.clear();
        }

            if (cleanupTime >= 0) {
                buf.append(", cleanup ").append(cleanupTime).append("ms");
            }
            buf.append("}, ");
            buf.append(MemoryUtil.getMemoryUsageLog());
            buf.append(')');
            logger.info(buf.toString());
        }
        final long unprocessedDocumentSize = fessConfig.getIndexerUnprocessedDocumentSizeAsInteger().longValue();