Note
This parameter is available starting with V1.4.
Description
memstore_limit_percentage specifies the percentage of the total available memory that is used for MemStore.
Attributes
Attribute |
Description |
|---|---|
| Type | INT |
| Default value | 0, indicating adaptive adjustment.
NoteStarting from V4.3.0, the default value is changed from 50 to 0. |
| Value range | [0, 100)
NoteStarting from V4.3.0, the value range is changed from (0, 100) to [0, 100). |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter. |
| Effective upon OBServer node restart | No. The setting takes effect immediately. |
Considerations
The
memstore_limit_percentageparameter is used to calculate the value ofmemstore_limit. The calculation formula is as follows:memstore_limit_percentage=memstore_limit/memory_sizeHere,
memory_sizeis the value specified when the tenant is created, indicating the amount of memory available to the tenant.In V4.3.x, you can also configure the percentage of tenant MemStore to the total tenant memory by using the tenant-level hidden parameter
_memstore_limit_percentage, starting from V4.3.0. The functionality and default value of_memstore_limit_percentageare the same as those of the cluster-level parametermemstore_limit_percentage. However, the effective scope is different. When configuring these parameters, note the following:- If you configure only
_memstore_limit_percentageormemstore_limit_percentage(not the default value), the configured value (not the default value) takes precedence. - If you configure both the tenant-level hidden parameter
_memstore_limit_percentage(not the default value) and the cluster-level parametermemstore_limit_percentage(not the default value), the value of_memstore_limit_percentagetakes precedence. - If neither parameter is configured or both are configured with the default value, the system adopts the following adaptive strategy:
- Tenants with 8 GB (real memory) or less are configured with a MemStore ratio of 40%.
- Tenants with more than 8 GB of memory are configured with a MemStore ratio of 50%.
- If you configure only
Examples
Set the percentage of tenant MemStore to 60% of the total available memory.
obclient> ALTER SYSTEM SET memstore_limit_percentage = 60;