.. module:: optuna.storages

optuna.storages

The :mod:~optuna.storages module defines a :class:~optuna.storages.BaseStorage class which abstracts a backend database and provides library-internal interfaces to the read/write histories of the studies and trials. Library users who wish to use storage solutions other than the default :class:~optuna.storages.InMemoryStorage should use one of the child classes of :class:~optuna.storages.BaseStorage documented below.

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RDBStorage RetryFailedTrialCallback fail_stale_trials JournalStorage InMemoryStorage run_grpc_proxy_server GrpcStorageProxy

optuna.storages.journal

:class:~optuna.storages.JournalStorage requires its backend specification and here is the list of the supported backends:

.. note:: If users would like to use any backends not supported by Optuna, it is possible to do so by creating a customized class by inheriting :class:optuna.storages.journal.BaseJournalBackend.

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journal.JournalFileBackend journal.JournalRedisBackend

Users can flexibly choose a lock object for :class:~optuna.storages.journal.JournalFileBackend and here is the list of supported lock objects:

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journal.JournalFileSymlinkLock journal.JournalFileOpenLock

Deprecated Modules

.. note:: The following modules are deprecated at v4.0.0 and will be removed in the future. Please use the modules defined in :mod:optuna.storages.journal.

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BaseJournalLogStorage JournalFileStorage JournalRedisStorage