flume-ng 测试过程中event丢失部分body数据

经过测试发现，当source端单event的body数据大于16字节后，输出到目标只剩下16字节。进过多源代码的分析，发现，源代码中进行了截取。

在LoggerSink.java中：

if (event != null) {

if (logger.isInfoEnabled()) {

logger.info("Event: " + EventHelper.dumpEvent(event));

}

}

我们去看EventHelper.java的dumpEvent方法：

private static final int DEFAULT_MAX_BYTES = 16;

public static String dumpEvent(Event event) {

return dumpEvent(event, DEFAULT_MAX_BYTES);

}

public static String dumpEvent(Event event, int maxBytes) {

StringBuilder buffer = new StringBuilder();

if (event == null || event.getBody() == null) {

buffer.append("null");

} else if (event.getBody().length == 0) {

// do nothing... in this case, HexDump.dump() will throw an exception

} else {

byte[] body = event.getBody();

byte[] data = Arrays.copyOf(body, Math.min(body.length, maxBytes));

ByteArrayOutputStream out = new ByteArrayOutputStream();

try {

HexDump.dump(data, 0, out, 0);

String hexDump = new String(out.toByteArray());

// remove offset since it's not relevant for such a small dataset

if(hexDump.startsWith(HEXDUMP_OFFSET)) {

hexDump = hexDump.substring(HEXDUMP_OFFSET.length());

}

buffer.append(hexDump);

} catch (Exception e) {

if(LOGGER.isInfoEnabled()) {

LOGGER.info("Exception while dumping event", e);

}

buffer.append("...Exception while dumping: ").append(e.getMessage());

}

String result = buffer.toString();

if(result.endsWith(EOL) && buffer.length() > EOL.length()) {

buffer.delete(buffer.length() - EOL.length(), buffer.length()).toString();

}

}

return "{ headers:" + event.getHeaders() + " body:" + buffer + " }";

}

不难看出，在event处理过程中，发生了数据截取操作。