Select a network type

Network types

Internet: Sending log data through the Internet can be limited by the network bandwidth. Additionally, network issues such as jitters, latency, and packet loss may affect the speed and stability of data transmission.
Alibaba Cloud intranet: The Alibaba Cloud intranet supports shared bandwidth at the gigabit-level and can transmit log data more quickly and stably than the Internet. The intranet includes the Virtual Private Cloud (VPC) environment and the classic network environment.
Global Acceleration: This network service accelerates log collection by using the edge nodes of Alibaba Cloud Content Delivery Network (CDN). Compared with the Internet, Global Acceleration provides lower transmission delay and greater stability.

intranet:
Whether your log data is transmitted through the Alibaba Cloud intranet depends on your server type and if the server and the Log Service Project are in the same region. The Alibaba Cloud intranet can transmit log data in only the following two scenarios:
- The ECS instances of your account and the Log Service Project are in the same region.
- The ECS instances of other accounts and the Log Service Project are in the same region.
Therefore, we recommend that you create a Log Service Project in the region where your ECS instances reside, and collect logs to this Project. Then the log data of the ECS instances is written to Log Service through the Alibaba Cloud intranet, without consuming the Internet bandwidth.

Note When you install a Logtail client on a server, you must select the region in which the Log Service Project resides. Otherwise, the log data cannot be collected.
Global Acceleration:
If your servers are located in your self-built IDCs overseas, or your servers are hosted by overseas cloud vendors, using the Internet to transmit data may cause problems such as high latency and unstable transmission. In this case, you can use Global Acceleration instead. Global Acceleration accelerates log collection by using the edge nodes of Alibaba Cloud CDN. Compared with data transmission through the Internet, Global Acceleration offers a more stable network with minimal transmission delays.
Internet:
We recommend that you select the Internet for the following two scenarios:
- The server is an ECS instance, but it does not reside in the same region as the Log Service Project.
- The server is located in your own IDC or provided by a vendors.


Server type	Reside in the same region as the Project	Configure an AliUid	Network type
ECS instances under your account	Yes	Not required	Alibaba Cloud intranet
ECS instances under your account	No	Not required	Internet or Global Acceleration
ECS instances of other accounts	Yes	Required	Alibaba Cloud intranet
ECS instances of other accounts	No	Required	Internet or Global Acceleration
Cloud vendor servers or your own IDC servers	-	Required	Internet or Global Acceleration

Note Log Service cannot obtain owner information of the ECS instances that are under other accounts or servers. Therefore, you need to configure an AliUid for each server after you complete the Logtail client installation. Otherwise, the server heartbeat is abnormal and the server logs cannot be collected. For more information, see Collect logs from non-Alibaba Cloud ECS instances or ECS instances not in your account.

Examples of selecting a network type

The following examples describe how to select an appropriate network in several common scenarios.

Note In the Global Acceleration scenario, the speed and reliability of data collection are important factors because the Log Service Project is created in the Hong Kong region but the servers are from the IDCs located worldwide. Therefore, we recommend that you select the Global Acceleration network type in the Hong Kong region when installing a Logtail client in similar scenarios. Compared with the Internet, Global Acceleration transmits log data with higher stability and performance.


Scenario	Region of the Log Service Project	Server type	Region of the ECS instance	Selected region for installing a Logtail client	Network type	Configure an AliUid
ECS and the Project are in the same region.	China East 1 (Hangzhou)	ECS of your current account	China East 1 (Hangzhou)	China East 1 (Hangzhou)	intranet	Not required
ECS and the Project are in different regions.	China East 2 (Shanghai)	ECS of your current account	China North 1 (Beijing)	China North 1 (Beijing)	Internet	Not required
Other accounts	China East 2 (Shanghai)	ECS belongs to other accounts.	China North 1 (Beijing)	China North 1 (Beijing)	Internet	Required
Server is in the local IDC.	China East 5 (Shenzhen)	Self-built IDC	-	China East 5 (Shenzhen)	Internet	Required
Global Acceleration	Hong Kong	Self-built IDC	-	Hong Kong	Global Acceleration	Required

Figure 1. Examples of selecting a network type

Update configurations after a classic network is switched to a VPC

After a Logtail client is installed, you must update the network configurations if your ECS instance is switched from a classic network to a VPC. To do so, follow these steps:

Restart the Logtail client as the administrator.
- Linux:
```
sudo /etc/init.d/ilogtaild stop
sudo /etc/init.d/ilogtaild start
```
- Windows:
  Open Management Tool in Control Panel, open Service, right-click LogtailWorker, and then select Restart.
Update machine group configurations.
- Custom ID
  If a custom ID is set to define the machine group, you can directly use the VPC network without updating machine group configurations.
- IP address
  If the ECS instance IP address is used when you define the machine group, you must replace the original IP address with the new IP address obtained by the restarted Logtail client. That is, the IP address field in the app_info.json file.
  The file path of app_info.json:
  - Linux: /usr/local/ilogtail/app_info.json
  - Windows x64: C:\Program Files (x86)\Alibaba\Logtail\app_info.json
  - Windows x32: C:\Program Files\Alibaba\Logtail\app_info.json