Requirements

Persistency Requirements		status: valid security: YES safety: ASIL_B
tags: persistency realizes: wp__feat_request
doc__feature_persistency_requirements		Generic Document

C++ and Rust language support		status: valid security: NO safety: QM
tags: persistency reqtype: Non-Functional satisfies: stkh_req__dev_experience__prog_languages
The Persistency shall provide native API support for both C++ and Rust programming languages.
feat_req__persistency__cpp_rust		Feature Requirement

Operating system agnostic implementation		status: valid security: NO safety: QM
tags: persistency reqtype: Non-Functional satisfies: stkh_req__functional_req__operating_system
The Persistency shall be operating system agnostic.
feat_req__persistency__os_agnostic		Feature Requirement

Variant management support		status: valid security: NO safety: QM
tags: persistency reqtype: Non-Functional satisfies: stkh_req__overall_goals__variant_management fulfilled by: feat_arc_sta__persistency__static
The Persistency shall ensure compatibility across different SW versions.
feat_req__persistency__variant_management		Feature Requirement

Dynamic memory allocation during runtime		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Non-Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall not allocate dynamic memory during runtime. All required dynamic memory shall be allocated during initialization. Note Dynamic memory allocation violates freedom from interference as the HEAP is a shared resource on OS process level. Additionally, fragmentation of the HEAP can lead to non-deterministic behavior of the application.
feat_req__persistency__dynamic_memory_alloc		Feature Requirement

Multiple KVS per application		status: valid security: NO safety: QM
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__data_persistency satisfied by: comp_req__persistency__multi_instance
The Persistency shall support multiple independent storages per application.
feat_req__persistency__multiple_kvs		Feature Requirement

Access from multiple applications		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall prevent access to a single KVS instance from multiple OS processes. Note Access from multiple OS processes violates freedom from interference, as applications can modify the same data concurrently.
feat_req__persistency__multiple_app		Feature Requirement

Separate data stores		status: valid security: YES safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__dependability__security_features satisfied by: comp_req__persistency__permission_control, comp_req__persistency__permission_err_handle fulfilled by: feat_arc_sta__persistency__static
The Persistency shall ensure that only authorized applications can access individual data stores. Note Access control is essential to prevent unauthorized access and modification of sensitive data. The Persistency shall implement mechanisms to enforce access control policies based on user roles and permissions.
feat_req__persistency__access_control		Feature Requirement

Configuration		status: valid security: YES safety: ASIL_B
tags: config, persistency reqtype: Functional satisfies: stkh_req__functional_req__file_based satisfied by: comp_req__persistency__constraints, comp_req__persistency__snapshot_max_num fulfilled by: feat_arc_sta__persistency__static
The Persistency shall support configuration via a configuration file. The configuration shall include: Global settings: Maximum number of KVS instances Maximum size of a key Settings for KVS instance: Instance identifier Storage URI Maximum number of Key-Value pairs Maximum number of snapshots Maximum consumed storage size (Including all metadata and redundant data) Security settings Redundancy settings Backend specific settings Configuration file shall be optional and all configuration attributes shall have sensible default values defined at compile time. Note To improve the user experience during rapid prototyping, the Persistency shall also be able to operate without a configuration file.
feat_req__persistency__cfg		Feature Requirement

Supported datatypes (Keys)		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__key_naming, comp_req__persistency__key_encoding, comp_req__persistency__key_uniqueness, comp_req__persistency__key_length fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__delete_key, feat_arc_dyn__persistency__read_key, feat_arc_dyn__persistency__write_key
The Persistency shall support UTF-8 encoded strings as valid key types.
feat_req__persistency__support_datatype_keys		Feature Requirement

Supported datatypes (Values)		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__value_data_types, comp_req__persistency__value_serialize, comp_req__persistency__value_length, comp_req__persistency__value_default, comp_req__persistency__value_reset fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__delete_key, feat_arc_dyn__persistency__read_key, feat_arc_dyn__persistency__write_key
The Persistency shall support storing both primitive and non-primitive (composite) datatypes as values.
feat_req__persistency__support_datatype_value		Feature Requirement

Default values		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__value_default, comp_req__persistency__value_reset, comp_req__persistency__default_value_types, comp_req__persistency__default_value_query, comp_req__persistency__default_value_config, comp_req__persistency__default_value_checksum fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__check_key_default, feat_arc_dyn__persistency__read_key
The Persistency shall support predefined default values for keys.
feat_req__persistency__default_values		Feature Requirement

Provisioning of default values via external file		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__file_based satisfied by: comp_req__persistency__default_value_types, comp_req__persistency__default_value_query, comp_req__persistency__default_value_config, comp_req__persistency__default_value_checksum fulfilled by: feat_arc_sta__persistency__static
The Persistency shall support import of default values using an external file. Note Default values are read-only and cannot be modified at runtime. This requirement addresses the provisioning of default values during initial deployment. See Tooling (feat_req__persistency__tooling).
feat_req__persistency__default_value_file		Feature Requirement

Retrieval of default values		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__default_value_types, comp_req__persistency__default_value_query, comp_req__persistency__default_value_config, comp_req__persistency__default_value_checksum fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__check_key_default, feat_arc_dyn__persistency__read_key
The Persistency shall support retrieval of the default value associated with a key.
feat_req__persistency__default_value_get		Feature Requirement

Reset to default values		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__default_value_types, comp_req__persistency__default_value_query, comp_req__persistency__default_value_config, comp_req__persistency__default_value_checksum
The Persistency shall support reset of individual key or all keys to their default values. This is only applicable for existing keys that have a predefined default value.
feat_req__persistency__reset_to_default		Feature Requirement

Store persistent data		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__data_persistency satisfied by: comp_req__persistency__persist_data_store_com, comp_req__persistency__pers_data_csum_write, comp_req__persistency__pers_data_store_bend, comp_req__persistency__pers_data_store_fmt fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__flush, feat_arc_dyn__persistency__snapshot_restore
The Persistency shall support storing of key-value pairs to persistent storage.
feat_req__persistency__store_data		Feature Requirement

Reset resistant storage		status: valid security: YES safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall ensure that write operations are reset resistant to prevent data corruption in case of expected or unexpected interruption. Note As the constant power supply can not be guaranteed in embedded systems, it is essential to ensure that write operations are completed successfully, or rolled back to the previous state in case of any kind of interruption.
feat_req__persistency__reset_resistant		Feature Requirement

Recovery from reset		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall recover to a consistent state after reset. Note After a reset, the Persistency shall ensure that all key-value pairs are in a consistent state, reflecting either the last successful write operation or the previous consistent state.
feat_req__persistency__recovery_from_reset		Feature Requirement

Atomic store operation		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall support atomic write operation for entire storage to ensure data consistency. Note Atomic write operation guarantee that either all key-value pairs are written, or no changes are made at all. This is required to prevent malfunctions when individual key-value pairs are dependent on each other.
feat_req__persistency__atomic_store		Feature Requirement

Write amplification minimization		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Non-Functional satisfies: stkh_req__app_architectures__support_data
The Persistency shall minimize the write amplification during data storage operations to enhance performance and prolong the lifespan of the underlying storage medium. Note Write amplification refers to the phenomenon where the amount of data written to the storage medium exceeds the amount of user data intended to be written. Minimizing write amplification is crucial for optimizing performance and reducing wear on storage devices, especially in embedded systems with limited number of program-erase cycles.
feat_req__persistency__write_amplification		Feature Requirement

Load persistent data		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__data_persistency satisfied by: comp_req__persistency__pers_data_csum_verify fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__read_from_storage
The Persistency shall support loading of key-value pairs from persistent storage.
feat_req__persistency__load_data		Feature Requirement

Cached access		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall support caching mechanisms to improve access times for frequently accessed key-value pairs.
feat_req__persistency__cached_access		Feature Requirement

Direct access		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__dependability__availability
The Persistency shall support direct access to key-value pairs without the necessity to load the entire storage to RAM in advance. Note Direct access improves availability of data and reduces memory consumption for large data sets.
feat_req__persistency__direct_access		Feature Requirement

Integrity check		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__persist_data_store_com, comp_req__persistency__pers_data_csum_write, comp_req__persistency__pers_data_csum_verify, comp_req__persistency__pers_data_store_bend, comp_req__persistency__pers_data_store_fmt fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__flush, feat_arc_dyn__persistency__read_from_storage
The Persistency shall detect and report data integrity issues.
feat_req__persistency__integrity_check		Feature Requirement

Confidential storage		status: valid security: YES safety: QM
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__data_persistency
The Persistency shall support confidential storage of key-value pairs using encryption mechanisms. Note Confidential storage is essential to protect sensitive data from unauthorized access, especially in scenarios where the storage medium may be exposed to potential threats.
feat_req__persistency__confidential_storage		Feature Requirement

Multiple storage backends		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall support multiple storage backends. More than one storage backend of the same type shall be optionally supported for the sake of redundancy. The storage backends shall be compile time configurable for each KVS instance. Note Storage backend represents an abstraction for the underlying storage format and mechanism. Configurable storage backends allow the user to select the most suitable solution for their specific use case (Performance, easy of use, resource consumption, …).
feat_req__persistency__storage_backends		Feature Requirement

Asynchronous operation		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__dependability__availability, stkh_req__app_architectures__support_request satisfied by: comp_req__persistency__async_api, comp_req__persistency__callback_support fulfilled by: feat_arc_sta__persistency__static, logic_arc_int__persistency__interface
The Persistency shall provide an asynchronous API for time consuming operations like loading and storing of data.
feat_req__persistency__async_api		Feature Requirement

Signalling completion of asynchronous operation		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__app_architectures__support_data satisfied by: comp_req__persistency__callback_support fulfilled by: feat_arc_sta__persistency__static
The Persistency shall provide a mechanism to signal the completion of an asynchronous operations to the application.
feat_req__persistency__async_completion		Feature Requirement

Snapshot create		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__snapshot_creation, comp_req__persistency__snapshot_id fulfilled by: feat_arc_sta__persistency__static, feat_arc_dyn__persistency__flush
The Persistency shall support explicit creation of snapshots. Snapshots are identified by unique IDs. Snapshots shall also include the version of the data layout. See Versioning (feat_req__persistency__versioning). Note Snapshots are point-in-time, read-only view on all key-value pairs at moment of snapshot creation. They are typically used for backup and rollback purposes. Implicit snapshots (e.g. created during store operation) shall be prevented to reduce storage consumption.
feat_req__persistency__snapshot_create		Feature Requirement

Snapshot restore		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__snapshot_rotate, comp_req__persistency__snapshot_restore fulfilled by: feat_arc_dyn__persistency__flush, feat_arc_dyn__persistency__read_from_storage, feat_arc_dyn__persistency__snapshot_restore
The Persistency shall support explicit restoration of snapshots.
feat_req__persistency__snapshot_restore		Feature Requirement

Snapshot remove		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__snapshot_rotate, comp_req__persistency__snapshot_delete
The Persistency shall support explicit removal of snapshots.
feat_req__persistency__snapshot_remove		Feature Requirement

Intra-Process data access		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__communication__intra_process satisfied by: comp_req__persistency__concurrency fulfilled by: feat_arc_sta__persistency__static
The Persistency shall support concurrent access to key-value pairs from multiple threads within the same process.
feat_req__persistency__concurrency		Feature Requirement

Versioning		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__functional_req__support_of_store satisfied by: comp_req__persistency__pers_data_version, comp_req__persistency__pers_data_schema
The Persistency shall support versioning for different data representation of KVS. Note Versioning is essential to ensure compatibility between different versions of the Persistency and the stored data. Each version shall be uniquely identifiable and include information of the data layout and structure.
feat_req__persistency__versioning		Feature Requirement

Update Mechanism		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__overall_goals__variant_management satisfied by: comp_req__persistency__pers_data_version, comp_req__persistency__pers_data_schema
The Persistency shall implement mechanisms to upgrade from one version to another, including multi-version jumps.
feat_req__persistency__update_mechanism		Feature Requirement

Random access time		status: valid security: NO safety: QM
tags: persistency reqtype: Non-Functional satisfies: stkh_req__execution_model__short_app_cycles
The Persistency shall ensure that random read access for key-value pair is completed with constant or logarithmic time complexity relative to the number of stored key-value pairs.
feat_req__persistency__fast_access		Feature Requirement

Tooling		status: valid security: NO safety: ASIL_B
tags: persistency reqtype: Non-Functional satisfies: stkh_req__functional_req__support_of_store
The Persistency shall provide tooling support for: viewing and modifying key-value pairs during development, testing and debugging provisioning of default values via external file
feat_req__persistency__tooling		Feature Requirement

Support development mode		status: valid security: YES safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__dependability__safety_features satisfied by: comp_req__persistency__eng_mode
The Persistency shall support the development mode. The development mode shall allow unrestricted data access and bypass security policies.
feat_req__persistency__dev_mode		Feature Requirement

Support production mode		status: valid security: YES safety: ASIL_B
tags: persistency reqtype: Functional satisfies: stkh_req__dependability__safety_features satisfied by: comp_req__persistency__field_mode
The Persistency shall support the production mode. The production mode should enforce the most restrictive data access controls feasible.
feat_req__persistency__prod_mode		Feature Requirement

AoU Requirements

Persistency Error handling		status: valid security: NO safety: ASIL_B
tags: environment, persistency reqtype: Functional mititages: feat_saf_fmea__persistency__message_nreived, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__not_sent, feat_saf_fmea__persistency__err_handl
The application shall handle if the feature persistency is not available.
aou_req__persistency__error_handling		Assumption of Use Requirement

Application deadlock		status: valid security: NO safety: ASIL_B
tags: environment, persistency reqtype: Functional
The application shall be designed in a way that deadlocks are avoided.
aou_req__persistency__appl_design		Assumption of Use Requirement

Application execution		status: valid security: NO safety: ASIL_B
tags: environment, persistency reqtype: Functional mititages: feat_saf_dfa__persistency__execution_blocking
The execution of persistency shall not be blocked by the application.
aou_req__persistency__appl_exec		Assumption of Use Requirement