Log data is stored on a shard of a Logstore where read/write operations are performed. A Logstore consists of multiple shards. Each shard is allocated with an left-closed and right-open interval (MD5 hash values) and does not overlap with the intervals of other shards. All the intervals construct the entire range of MD5 hash values.
A shard is a basic read and write unit in each Logstore. You can specify the number of shards in each Logstore. Each shard has limits on service capabilities:
- Write: 5 MB/s, 500 times/s.
- Read: 10 Mbit/s, 100 times/s.
To read data from a shard, you must specify the shard. To write data to a shard, you do not need to specify the shard. Instead, you can use the load balancing mode. In this mode, data is written to multiple shards based on automatic balancing. This ensures high availability of write operations.
The following table describes the parameters that define a shard:
| Parameter | Type | Required | Description |
|---|---|---|---|
| shardID | int | Yes | The unique ID of a shard in the Logstore. The shard ID is automatically generated by the system. |