View and adjust system parameters

What are system parameters?

System parameters in RisingWave refer to the parameters that advanced users can use to adjust how internal components work in RisingWave.

Currently, these system parameters are availble in RisingWave.

Parameter	Description
barrier_interval_ms	The time interval of the periodic barriers.
checkpoint_interval	Specify the number of barriers for which a checkpoint will be created. The value must be a positive integer.
sstable_size_mb	The target size of SSTable.
block_size_kb	The size of each block in bytes in SSTable.
bloom_false_positive	False positive rate of bloom filter in SSTable.
state_store	The state store URL.
data_directory	The remote directory for storing data and metadata objects.
backup_storage_url	The URL of the remote storage for backups.
backup_storage_directory	The directory of the remote storage for backups.
telemetry_enabled	Whether to enable telemetry or not. For more information, see Telemetry.

How to view system parameters?

You can use the SHOW PARAMETERS statement to view the system parameters and their settings.

SHOW PARAMETERS;

--------------------------
           Name           |    Value    
--------------------------+-------------
 barrier_interval_ms      | 1000
 checkpoint_interval      | 10
 sstable_size_mb          | 256
 block_size_kb            | 64
 bloom_false_positive     | 0.001
 state_store              | 
 data_directory           | hummock_001
 backup_storage_url       | memory
 backup_storage_directory | backup
 telemetry_enabled        | true

How to adjust system parameters?

You can use the ALTER SYSTEM SET statement to revise the setting of a system parameter. Note that currently only checkpoint_interval and telemetry_enabled can be set.

note

As RisingWave reads system parameters at different times, there is no guarantee that a parameter value change takes effect immediately. We recommend that you adjust system parameters before running a streaming query after your RisingWave cluster starts.

The full syntax of the ALTER SYSTEM SET statement is:

ALTER SYSTEM SET parameter_name { TO | = } { value | 'value' | DEFAULT };