Merge branch 'develop' of github.com:emqx/kuiper into develop

docs/en_US/rules/sources/mqtt.md

@@ -57,16 +57,44 @@ The location of certification path. It can be an absolute path, or a relative pa
 
 The location of private key path. It can be an absolute path, or a relative path.  For more detailed information, please refer to ``certificationPath``. Such as ``d3807d9fa5-private.pem.key``.
 
+### bufferLength
+
+specify the maximum number of messages to be buffered in the memory. This is used to avoid the extra large memory usage that would cause out of memory error. Notice that the memory usage will be varied to the actual buffer. Increase the length here won't increase the initial memory allocation so it is safe to set a large buffer length. The default value is 102400, that is if each payload size is about 100 bytes, the maximum buffer size will be about 102400 * 100B ~= 10MB.
+
 ### kubeedgeVersion
 
 kubeedge 版本号，不同的版本号对应的文件内容不同。
 
 ### kubeedgeModelFile
 
-kubeedge 模版文件名，文件指定放在 etc/sources 文件夹中
+kubeedge 模版文件名，文件指定放在 etc/sources 文件夹中，样例格式如下：
+
+```json
+{
+	"deviceModels": [{
+		"name": "device1",
+		"properties": [{
+			"name": "temperature",
+			"dataType": "int"
+		}, {
+			"name": "temperature-enable",
+			"dataType": "string"
+		}]
+	}]
+}
+```
 
-### bufferLength
-specify the maximum number of messages to be buffered in the memory. This is used to avoid the extra large memory usage that would cause out of memory error. Notice that the memory usage will be varied to the actual buffer. Increase the length here won't increase the initial memory allocation so it is safe to set a large buffer length. The default value is 102400, that is if each payload size is about 100 bytes, the maximum buffer size will be about 102400 * 100B ~= 10MB.
+#### deviceModels.name
+
+设备名称,与订阅主题中的字段匹配，位于第三和第四个“/”之间的内容。例如：$ke/events/device/device1/data/update
+
+#### properties.name
+
+字段名称
+
+#### properties.dataType
+
+期望的字段类型
 
 ## Override the default settings
 

docs/zh_CN/rules/sources/mqtt.md

@@ -58,17 +58,44 @@ MQTT 连接密码。如果指定了 `certificationPath` 或者 `privateKeyPath`
 
 私钥路径。可以为绝对路径，也可以为相对路径。更详细的信息，请参考 `certificationPath`，比如 `d3807d9fa5-private.pem.key`。
 
+### bufferLength
+
+指定最大缓存消息数目。该参数主要用于防止内存溢出。实际内存用量会根据当前缓存消息数目动态变化。增大该参数不会增加初始内存分配量，因此设置较大的数值是安全的。该参数默认值为102400；如果每条消息为100字节，则默认情况下，缓存最大占用内存量为102400 * 100B ~= 10MB. 
+
 ### kubeedgeVersion
 
 kubeedge 版本号，不同的版本号对应的文件内容不同。
 
 ### kubeedgeModelFile
 
-kubeedge 模版文件名，文件指定放在 etc/sources 文件夹中
+kubeedge 模版文件名，文件指定放在 etc/sources 文件夹中，样例格式如下：
+
+```json
+{
+	"deviceModels": [{
+		"name": "device1",
+		"properties": [{
+			"name": "temperature",
+			"dataType": "int"
+		}, {
+			"name": "temperature-enable",
+			"dataType": "string"
+		}]
+	}]
+}
+```
 
-### bufferLength
+#### deviceModels.name
 
-指定最大缓存消息数目。该参数主要用于防止内存溢出。实际内存用量会根据当前缓存消息数目动态变化。增大该参数不会增加初始内存分配量，因此设置较大的数值是安全的。该参数默认值为102400；如果每条消息为100字节，则默认情况下，缓存最大占用内存量为102400 * 100B ~= 10MB. 
+设备名称,与订阅主题中的字段匹配，位于第三和第四个“/”之间的内容。例如：$ke/events/device/device1/data/update
+
+#### properties.name
+
+字段名称
+
+#### properties.dataType
+
+期望的字段类型
 
 ## 重载默认设置