In the industrial scenario, it is usually the remote periodic output model, and the online server needs to pull down the new model to update the old model without service interruption.
## Server Monitor
Paddle Serving provides an automatic monitoring script. After the remote address updates the model, the new model will be pulled to update the local model. At the same time, the `fluid_time_stamp` in the local model folder will be updated to realize model hot loading.
Currently, the following types of Monitors are supported:
| general | Without authentication, you can directly access the download file by `wget` (such as FTP and BOS which do not need authentication) | `general_host` General remote host. |
| hdfs/afs(HadoopMonitor) | The remote is HDFS or AFS, and relevant commands are executed through Hadoop-client | `hadoop_bin` Path of Hadoop binary file.<br/>`fs_name` Hadoop fs_name. Not used if set in Hadoop-client.<br/>`fs_ugi` Hadoop fs_ugi, Not used if set in Hadoop-client. |
| ftp | The remote is FTP, and relevant commands are executed through `ftplib`(Using this monitor, you need to install `ftplib` with command `pip install ftplib`) | `ftp_host` FTP remote host.<br>`ftp_port` FTP remote port.<br>`ftp_username` FTP username. Not used if anonymous access.<br>`ftp_password` FTP password. Not used if anonymous access. |
| `remote_path` | Specify the base path for the remote | / |
| `remote_model_name` | Specify the model name to be pulled from the remote | / |
| `remote_donefile_name` | Specify the donefile name that marks the completion of the remote model update | / |
| `local_path` | Specify local work path | / |
| `local_model_name` | Specify local model name | / |
| `local_timestamp_file` | Specify the timestamp file used locally for hot loading, The file is considered to be placed in the `local_path/local_model_name` folder. | `fluid_time_file` |
| `local_tmp_path` | Specify the path of the folder where temporary files are stored locally. If it does not exist, it will be created automatically. | `_serving_monitor_tmp` |
| `interval` | Specify the polling interval in seconds. | `10` |
| `unpacked_filename` | Monitor supports the `tarfile` packaged remote model file. If the remote model is in a packaged format, you need to set this option to tell monitor the name of the extracted file. | `None` |
| `debug` | If the `--debug` option is added, more detailed intermediate information will be output. | This option is not added by default. |
The following is an example of HadoopMonitor to show the model hot loading of Paddle Serving.
## HadoopMonitor example
In this example, the production model is uploaded to HDFS in `product_path` folder, and the server hot loads the model in `server_path` folder:
```shell
.
├── product_path
└── server_path
```
### Product model
Run the following Python code products model in `product_path` folder. Every 60 seconds, the package file of Boston house price prediction model `uci_housing.tar.gz` will be generated and uploaded to the path of HDFS `/`. After uploading, the timestamp file `donefile` will be updated and uploaded to the path of HDFS `/`.
The above code monitors the remote timestamp file `/donefile` of the remote HDFS address `/` every 10 seconds by polling. When the remote timestamp file changes, the remote model is considered to have been updated. Pull the remote packaging model `/uci_housing.tar.gz` to the local temporary path `./_tmp/uci_housing.tar.gz`. After unpacking to get the model file `./_tmp/uci_housing_model`, update the local model `./uci_housing_model` and the model timestamp file `./uci_housing_model/fluid_time_file` of Paddle Serving.
The expected output is as follows:
```shell
2020-04-02 10:12 INFO [monitor.py:85] _hadoop_bin: /hadoop-3.1.2/bin/hadoop
2020-04-02 10:12 INFO [monitor.py:85] _fs_name:
2020-04-02 10:12 INFO [monitor.py:85] _fs_ugi:
2020-04-02 10:12 INFO [monitor.py:209] AFS prefix cmd: /hadoop-3.1.2/bin/hadoop fs
2020-04-02 10:12 INFO [monitor.py:85] _remote_path: /
2020-04-02 10:12 INFO [monitor.py:85] _remote_model_name: uci_housing.tar.gz
2020-04-02 10:12 INFO [monitor.py:85] _remote_donefile_name: donefile
2020-04-02 10:12 INFO [monitor.py:85] _local_model_name: uci_housing_model
2020-04-02 10:12 INFO [monitor.py:85] _local_path: .
2020-04-02 10:12 INFO [monitor.py:85] _local_timestamp_file: fluid_time_file
2020-04-02 10:12 INFO [monitor.py:85] _local_tmp_path: _tmp
2020-04-02 10:12 INFO [monitor.py:85] _interval: 10
"--type",type=str,default='general',help="Type of remote server")
parser.add_argument(
"--remote_path",
type=str,
required=True,
help="The base path for the remote")
parser.add_argument(
"--remote_model_name",
type=str,
required=True,
help="The model name to be pulled from the remote")
parser.add_argument(
"--remote_donefile_name",
type=str,
required=True,
help="The donefile name that marks the completion of the remote model update"
)
parser.add_argument(
"--local_path",type=str,required=True,help="Local work path")
parser.add_argument(
"--local_model_name",type=str,required=True,help="Local model name")
parser.add_argument(
"--local_timestamp_file",
type=str,
default='fluid_time_file',
help="The timestamp file used locally for hot loading, The file is considered to be placed in the `local_path/local_model_name` folder."
)
parser.add_argument(
"--local_tmp_path",
type=str,
default='_serving_monitor_tmp',
help="The path of the folder where temporary files are stored locally. If it does not exist, it will be created automatically"
)
parser.add_argument(
"--unpacked_filename",
type=str,
default=None,
help="If the model of the remote production is a packaged file, the unpacked file name should be set. Currently, only tar packaging format is supported."
)
parser.add_argument(
"--interval",
type=int,
default=10,
help="The polling interval in seconds")
parser.add_argument(
"--debug",action='store_true',help="If set, output more details")
