Logs are records of changes made within a system. The records are ordered by time. These records contain information about operations on specific objects and the results. Log data is stored in different forms such as log files, log events, binary logs, and metric data. Each log file consists of one or more log entries. A log entry is the basic unit of data that can be processed in Log Service. Each log entry describes a single system event.

Log groups

A log group is a group of logs that serves as the basic unit for read/write operations.


A log topic is used to classify logs in a Logstore. You can specify a topic for logs written to Log Service. Then, you can specify the topic when you query the logs.


A project in Log Service is used to separate and manage different resources. You can use a project to manage all the logs of an application and related log resources. You can use a project to manage server groups that are configured for log collection and Logstores that are created in the project. All of your Log Service resources are accessed through the endpoints of projects.


A Logstore in Log Service is used for log data storage and query. A Logstore belongs to one project. You can create multiple Logstores for a project.


A Logstore consists of multiple shards. Each shard is allocated with an MD5 hash value interval that is left closed and right open and does not overlap with each other. All the intervals construct the entire range of MD5 hash values.