The terms are listed in ascending alphabetical order.
B
Backend
A client App is running in the backend when the mobile phone displays the Home screen or in the screen-saving state, or when the user is operating another App.
BizType
A business type, which is the unique identifier of a business scenario. After data is pushed, the MSS SDK of the client distributes the data to the corresponding business module based on BizType.
Business dimension
There are two business dimensions: user and device. The MSS server pushes data by user or device.
F
Frontend
The client App is running.
I
Idempotence
Operations are applied multiple times based on the thirdMsgId field in the SyncOrder parameter, and succeed only once with the unique combination of bizType, linkToken, and thirdMsgId. New data will be discarded and not be added to the database. The API returns a success message with the result code “DUPLICAT ED_BIZ _ID”.
M
Multi-device Sync
A message is synchronized to all client-installed devices of a user. After the user logs in to the client that is installed on two or more devices, all the devices can receive the message. If the user uninstalls the client, re-installs it, and goes online again, the message will be pushed again.
MSS data
MSS data needs to be pushed through the MSS server.
MSS push
The MSS server proactively pushes one copy of data to the client. If the client that calls the business is online, data push is triggered immediately. Otherwise, the MSS server will push the data after the client goes online.
O
Online
The client App is connected to the network and maintains a stable TCP connection. When running in the backend, the client App is still online on most Android mobile phones but online for only 3 minutes on iPhones due to the iOS restrictions.
P
Persistence
A mechanism that converts program data between the persistent and transient states. In MSS, the persistence mechanism produces persistent data and non-persistent data.
- Persistent data: If a user is offline, the data will be stored in the database permanently. After the user goes online, the MSS SDK triggers data synchronization to the user.
- Non-persistent data: If a user is online, the data is pushed to the user immediately. If the user is offline, the data is discarded directly and will not be sent to the user after the user goes online.
Push type
There are two push types: designated push and global push.
- Designated push: pushes a piece of data to a designated user or device.
- Global push: pushes a piece of data to all online users or devices. Global push uses multi-device synchronization.
S
Single-device push
A message is pushed only to the device which a user uses for the latest login to the client. The message is pushed only once. If the user uninstalls the client, re-installs it, and goes online again, the message will not be pushed again. If the user logs in to the client from another device, the message will not be pushed to the device.
Sync
Sync refers to the MSS data synchronization service that the MSS server synchronizes data to the client App.
T
Threshold
If a user is offline for a long time and the server keeps on generating data, it may lead to a data backlog in MSS. The threshold specifies the upper limit of the amount of backlog data. When a data backlog occurs, only the latest data within the threshold is retained. Earlier data beyond the threshold will be discarded.