Version: latest

Tenant Resource Limitation

Currently, the resource isolation of CnosDB is tenant-level. There are two types of restrictions: one is to limit the objects created by tenants; One is to limit the size and number of times tenants can read and write data.Both types of restrictions can be set using the same SQL, and this SQL can only be used by the superuser.

Syntax

alter tenant <tenant_name> set
    object_config 
         max_users_number = <num>
         max_databases = <num>
         max_shard_number = <num>
         max_replicate_number = <num>
         max_retention_time = <num>,
     coord_data_in
         remote_max = <num>
         remote_initial = <num>
         remote_refill = <num>
         remote_interval = <num>
         local_max = <num>
         local_initial = <num>,
     coord_data_out
         ...
     coord_queries
         ...
     coord_writes
         ...
     http_data_in
         ...
     http_data_out
         ...
     http_queries
         ...
     http_writes
         ...
;

Parameter Description

tenant_name: Tenant name.
comment: description of tenants.
drop_after: specifies the useful time of the tenant, in the format `'1d' for 1 day etc.
Remaining parameters: belongs to the _limiter tenant resource limit, classified as:
- Object limits the number of object_config: tenant objects and storage limits.
- Read and write limit request_config:
  - Coordination Layer Configuration:
    - coord_data_in: Rental data input configuration, including remote and local resource restrictions.
    - coord_data_out: Tenant coordination level data output configuration, including remote and local resource restrictions.
    - coord_queries: Tenant Lookup configuration, including remote and local resource restrictions.
    - coord_writes: Tenant coordination layer writes into the configuration, including remote and local resource restrictions.
  - HTTP Layer Configuration:
    - http_data_in: Tenant HTTP layer data input configuration that supports remote and local limits.
    - http_data_out: Tenant HTTP layer data output configuration that supports remote and local limits.
    - http_queries: Tenant HTTP Layer Configuration supports remote and local limits.
    - http_writes: Tenant write configuration to support remote and local limits.

object_config, object limit, the parameters included are as follows:

Parameter name	Description	Required	Units
max_users_number	Specifies the maximum number of users (members) to be a tenant; when set to null, it is unbounded.	Yes	Count
max_databases	Specifies the maximum number of databases for each tenant; when set to null, it is unlimited.	Yes	Count
max_shard_number	Specifies the maximum number of shards that can be created in a tenant's database; when set to null, this is unlimited.	Yes	Count
max_replica_number	Specifies the maximum number of replicas that can be created for the database under the tenant; when set to null, this is unlimited.	Yes	Count
max_retention_time	Specifies the maximum TTL parameter of the database under the tenant. When null, it is unlimited.	Yes	Day

Example:

object_config
  max_users_number= 1
  max_databases= 3
  max_shard_number= 2
  max_replicate_number= 2
  max_retention_time= 30
,

request_config read and write Request limit, containing the following configuration entry:

Parameter	Description	Required
coord_data_in	Coordinate level data input limit	Yes
coord_data_out	Coordinating Layer Data Output Limit	Yes
coord_queries	Coordinate Query Limit	Yes
coord_writes	Coordination write limit	Yes
http_data_in	HTTP Layer Data Input Limit	Yes
http_data_out	HTTP Layer Data Output Limit	Yes
http_queries	HTTP Layer Query Limit	Yes
http_writes	HTTP Layer Write Limit	Yes

The parameter limitation is implemented through the token bucket algorithm, which consists of two parts: one is the remote token bucket on meta, specified by 'remote_max', 'remote_initial', 'remote_defill', and 'remote_initial'; the other is the local token bucket on data, specified by 'local_max', and the unit of the token is bytes.

Token bucket contains the following parameter:

Parameter name	Description	Required	Units
remote_max	Maximum number of tokens for remote bucket	Yes	Count
remote_initial	Initial tokens for remote bucket	Yes	Count
remote_refill	Number of tokens to fill	Yes	Count
remote_interval	Fill interval (milliseconds)	Yes	ms
local_max	Maximum number of tokens in local bucket	Yes	Count
local_initial	Number of initial tokens for local bucket	Yes	Count

The following example bucket setup allows 10KB of data to be written every 100ms and 10KB of data to be cased every 100ms;

Example data writing settings

coord_data_in   remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
coord_data_out  remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,

Overall Example

create tenant test;
alter tenant test set 
object_config 
                max_users_number = 1
                max_databases = 3
                max_shard_number = 2
                max_replicate_number = 2
                max_retention_time = 30,
coord_data_in   remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
coord_data_out  remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
coord_queries   remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,    
coord_writes    remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
http_data_in   remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
http_data_out  remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,
http_queries   remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0,    
http_writes    remote_max = 10000
                remote_initial = 0
                remote_refill = 10000
                remote_interval = 100
                local_max = 10000
                local_initial = 0
;

Tenant Resource Limitation

Syntax​

Parameter Description​

object_config, object limit, the parameters included are as follows:​

Example:​

request_config read and write Request limit, containing the following configuration entry:​

Token bucket contains the following parameter:​

Example data writing settings​

Overall Example​