Modin Configuration Settings

To adjust Modin’s default behavior, you can set the value of Modin configs by setting an environment variable or by using the modin.config API. To list all available configs in Modin, please run python -m modin.config to print all Modin configs with descriptions.

Public API

Potentially, the source of configs can be any, but for now only environment variables are implemented. Any environment variable originate from EnvironmentVariable, which contains most of the config API implementation.

class modin.config.envvars.EnvironmentVariable

Base class for environment variables-based configuration.

classmethod get() → Any

Get config value.

Returns

Decoded and verified config value.

Return type

Any

classmethod get_help() → str

Generate user-presentable help for the config.

Return type

str

classmethod get_value_source() → ValueSource

Get value source of the config.

Return type

ValueSource

classmethod once(onvalue: Any, callback: Callable) → None

Execute callback if config value matches onvalue value.

Otherwise accumulate callbacks associated with the given onvalue in the _once container.

Parameters

• onvalue (Any) – Config value to set.

• callback (callable) – Callable that should be executed if config value matches onvalue.

classmethod put(value: Any) → None

Set config value.

Parameters

value (Any) – Config value to set.

classmethod subscribe(callback: Callable) → None

Add callback to the _subs list and then execute it.

Parameters

callback (callable) – Callable to execute.

Modin Configs List

Config Name	Env. Variable Name	Default Value	Description	Options
AsvDataSizeConfig	MODIN_ASV_DATASIZE_CONFIG		Allows to override default size of data (shapes).
AsvImplementation	MODIN_ASV_USE_IMPL	modin	Allows to select a library that we will use for testing performance.	(‘modin’, ‘pandas’)
AsyncReadMode	MODIN_ASYNC_READ_MODE	False	It does not wait for the end of reading information from the source. Can break situations when reading occurs in a context, when exiting from which the source is deleted.
BenchmarkMode	MODIN_BENCHMARK_MODE	False	Whether or not to perform computations synchronously.
CIAWSAccessKeyID	AWS_ACCESS_KEY_ID	foobar_key	Set to AWS_ACCESS_KEY_ID when running mock S3 tests for Modin in GitHub CI.
CIAWSSecretAccessKey	AWS_SECRET_ACCESS_KEY	foobar_secret	Set to AWS_SECRET_ACCESS_KEY when running mock S3 tests for Modin in GitHub CI.
CpuCount	MODIN_CPUS	multiprocessing.cpu_count()	How many CPU cores to use during initialization of the Modin engine.
DoLogRpyc	MODIN_LOG_RPYC		Whether to gather RPyC logs (applicable for remote context).
DoTraceRpyc	MODIN_TRACE_RPYC		Whether to trace RPyC calls (applicable for remote context).
DoUseCalcite	MODIN_USE_CALCITE	True	Whether to use Calcite for HDK queries execution.
Engine	MODIN_ENGINE	Ray	Distribution engine to run queries by.	(‘Ray’, ‘Dask’, ‘Python’, ‘Native’, ‘Unidist’)
ExperimentalGroupbyImpl	MODIN_EXPERIMENTAL_GROUPBY	False	Set to true to use Modin’s experimental group by implementation. Experimental groupby is implemented using a range-partitioning technique, note that it may not always work better than the original Modin’s TreeReduce and FullAxis implementations. For more information visit the according section of Modin’s documentation: TODO: add a link to the section once it’s written.
ExperimentalNumPyAPI	MODIN_EXPERIMENTAL_NUMPY_API	False	Set to true to use Modin’s experimental NumPy API.
GithubCI	MODIN_GITHUB_CI	False	Set to true when running Modin in GitHub CI.
GpuCount	MODIN_GPUS		How may GPU devices to utilize across the whole distribution.
HdkFragmentSize	MODIN_HDK_FRAGMENT_SIZE		How big a fragment in HDK should be when creating a table (in rows).
HdkLaunchParameters	MODIN_HDK_LAUNCH_PARAMETERS	{‘enable_union’: 1, ‘enable_columnar_output’: 1, ‘enable_lazy_fetch’: 0, ‘null_div_by_zero’: 1, ‘enable_watchdog’: 0, ‘enable_thrift_logs’: 0, ‘enable_multifrag_execution_result’: 1, ‘cpu_only’: 1, ‘enable_lazy_dict_materialization’: 0, ‘log_dir’: ‘pyhdk_log’}	Additional command line options for the HDK engine. Please visit OmniSci documentation for the description of available parameters: https://docs.omnisci.com/installation-and-configuration/config-parameters#configuration-parameters-for-omniscidb
IsDebug	MODIN_DEBUG		Force Modin engine to be “Python” unless specified by $MODIN_ENGINE.
IsExperimental	MODIN_EXPERIMENTAL		Whether to Turn on experimental features.
IsRayCluster	MODIN_RAY_CLUSTER		Whether Modin is running on pre-initialized Ray cluster.
LogFileSize	MODIN_LOG_FILE_SIZE	10	Max size of logs (in MBs) to store per Modin job.
LogMemoryInterval	MODIN_LOG_MEMORY_INTERVAL	5	Interval (in seconds) to profile memory utilization for logging.
LogMode	MODIN_LOG_MODE	disable	Set LogMode value if users want to opt-in.	(‘enable’, ‘disable’, ‘enable_api_only’)
Memory	MODIN_MEMORY		How much memory (in bytes) give to an execution engine. Notes: In Ray case: the amount of memory to start the Plasma object store with. In Dask case: the amount of memory that is given to each worker depending on CPUs used.
MinPartitionSize	MODIN_MIN_PARTITION_SIZE	32	Minimum number of rows/columns in a single pandas partition split. Once a partition for a pandas dataframe has more than this many elements, Modin adds another partition.
NPartitions	MODIN_NPARTITIONS	equals to MODIN_CPUS env	How many partitions to use for a Modin DataFrame (along each axis).
PersistentPickle	MODIN_PERSISTENT_PICKLE	False	Whether serialization should be persistent.
ProgressBar	MODIN_PROGRESS_BAR	False	Whether or not to show the progress bar.
RayRedisAddress	MODIN_REDIS_ADDRESS		Redis address to connect to when running in Ray cluster.
RayRedisPassword	MODIN_REDIS_PASSWORD	random string	What password to use for connecting to Redis.
ReadSqlEngine	MODIN_READ_SQL_ENGINE	Pandas	Engine to run read_sql.	(‘Pandas’, ‘Connectorx’)
SocksProxy	MODIN_SOCKS_PROXY		SOCKS proxy address if it is needed for SSH to work.
StorageFormat	MODIN_STORAGE_FORMAT	Pandas	Engine to run on a single node of distribution.	(‘Pandas’, ‘Hdk’, ‘Pyarrow’, ‘Cudf’)
TestDatasetSize	MODIN_TEST_DATASET_SIZE		Dataset size for running some tests.	(‘Small’, ‘Normal’, ‘Big’)
TestRayClient	MODIN_TEST_RAY_CLIENT	False	Set to true to start and connect Ray client before a testing session starts.
TestReadFromPostgres	MODIN_TEST_READ_FROM_POSTGRES	False	Set to true to test reading from Postgres.
TestReadFromSqlServer	MODIN_TEST_READ_FROM_SQL_SERVER	False	Set to true to test reading from SQL server.
TrackFileLeaks	MODIN_TEST_TRACK_FILE_LEAKS	True	Whether to track for open file handles leakage during testing.

Usage Guide

See example of interaction with Modin configs below, as it can be seen config value can be set either by setting the environment variable or by using config API.

import os

# Setting `MODIN_STORAGE_FORMAT` environment variable.
# Also can be set outside the script.
os.environ["MODIN_STORAGE_FORMAT"] = "Hdk"

import modin.config
import modin.pandas as pd

# Checking initially set `StorageFormat` config,
# which corresponds to `MODIN_STORAGE_FORMAT` environment
# variable
print(modin.config.StorageFormat.get()) # prints 'Hdk'

# Checking default value of `NPartitions`
print(modin.config.NPartitions.get()) # prints '8'

# Changing value of `NPartitions`
modin.config.NPartitions.put(16)
print(modin.config.NPartitions.get()) # prints '16'