Persistency KVS Architecture

Persistency KVS Feature Architecture		status: valid security: NO safety: ASIL_B
tags: persistency version: 1 realizes: wp__feature_arch
doc__persistency_kvs_architecture		Generic Document

Overview

The Key-Value-Storage (kvs) provides the capability to efficiently store, retrieve, and manage key-value pairs in a persistent storage system.

Description

• kvs organize data as pairs, where each unique key is associated with a specific value. The key acts as a unique identifier for getting the value.

• The data is persisted in JSON format to the file system, providing a human-readable, and widely supported way to store and manage key-value pairs.

• The JSON data persisted is according to RFC-8259.

Glossary:

• User: Program code that is written by a person that initiates the given functionality call or receives a callback.

Requirements

Overview of Feature Requirements

Title	ID
Separate data stores	feat_req__persistency__access_control
Asynchronous operation	feat_req__persistency__async_api
Signalling completion of asynchronous operation	feat_req__persistency__async_completion
Atomic store operation	feat_req__persistency__atomic_store
Cached access	feat_req__persistency__cached_access
Configuration	feat_req__persistency__cfg
Intra-Process data access	feat_req__persistency__concurrency
Confidential storage	feat_req__persistency__confidential_storage
C++ and Rust language support	feat_req__persistency__cpp_rust
Provisioning of default values via external file	feat_req__persistency__default_value_file
Retrieval of default values	feat_req__persistency__default_value_get
Default values	feat_req__persistency__default_values
Support development mode	feat_req__persistency__dev_mode
Direct access	feat_req__persistency__direct_access
Dynamic memory allocation during runtime	feat_req__persistency__dynamic_memory_alloc
Random access time	feat_req__persistency__fast_access
Integrity check	feat_req__persistency__integrity_check
Load persistent data	feat_req__persistency__load_data
Access from multiple applications	feat_req__persistency__multiple_app
Multiple KVS per application	feat_req__persistency__multiple_kvs
Operating system agnostic implementation	feat_req__persistency__os_agnostic
Support production mode	feat_req__persistency__prod_mode
Recovery from reset	feat_req__persistency__recovery_from_reset
Reset resistant storage	feat_req__persistency__reset_resistant
Reset to default values	feat_req__persistency__reset_to_default
Snapshot create	feat_req__persistency__snapshot_create
Snapshot remove	feat_req__persistency__snapshot_remove
Snapshot restore	feat_req__persistency__snapshot_restore
Multiple storage backends	feat_req__persistency__storage_backends
Store persistent data	feat_req__persistency__store_data
Supported datatypes (Keys)	feat_req__persistency__support_datatype_keys
Supported datatypes (Values)	feat_req__persistency__support_datatype_value
Tooling	feat_req__persistency__tooling
Update Mechanism	feat_req__persistency__update_mechanism
Variant management support	feat_req__persistency__variant_management
Versioning	feat_req__persistency__versioning
Write amplification minimization	feat_req__persistency__write_amplification

Rationale Behind Architecture Decomposition

• The architecture has one component comp__persistency_kvs and it uses mod__baselibs for JSON handling and file system access.

Static Architecture

The static view shows the feature with its logical interface and the components implementing it. The diagram is generated from the Sphinx Needs model.

Static Architecture		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__access_control, feat_req__persistency__async_api, feat_req__persistency__async_completion, feat_req__persistency__cfg, feat_req__persistency__concurrency, feat_req__persistency__default_value_file, feat_req__persistency__default_value_get, feat_req__persistency__default_values, feat_req__persistency__integrity_check, feat_req__persistency__load_data, feat_req__persistency__snapshot_create, feat_req__persistency__store_data, feat_req__persistency__support_datatype_keys, feat_req__persistency__support_datatype_value, feat_req__persistency__variant_management includes: logic_arc_int__persistency__interface violated_by: feat_saf_dfa__persistency__execution_blocking
feat_arc_sta__persistency__static		Feature & Feature Package Diagram

Dynamic Architecture

The dynamic views describe the interactions between the user and the components of the feature for the main use cases of the KVS.

Check if key contains default value		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__default_value_get, feat_req__persistency__default_values violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__check_key_default		Feature Sequence Diagram

Delete key from KVS instance		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__support_datatype_keys, feat_req__persistency__support_datatype_value violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__delete_key		Feature Sequence Diagram

Flush to permanent storage		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__integrity_check, feat_req__persistency__snapshot_create, feat_req__persistency__snapshot_restore, feat_req__persistency__store_data violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__flush		Feature Sequence Diagram

Read key value		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__default_value_get, feat_req__persistency__default_values, feat_req__persistency__support_datatype_keys, feat_req__persistency__support_datatype_value violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__read_key		Feature Sequence Diagram

Read data from permanent storage		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__integrity_check, feat_req__persistency__load_data, feat_req__persistency__snapshot_restore violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__read_from_storage		Feature Sequence Diagram

Write value to key		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__support_datatype_keys, feat_req__persistency__support_datatype_value violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__write_key		Feature Sequence Diagram

Restore snapshot		status: valid security: YES safety: ASIL_B
version: 1 belongs to: feat__persistency fulfils: feat_req__persistency__snapshot_restore, feat_req__persistency__store_data violated_by: feat_saf_fmea__persistency__corrupted_message, feat_saf_fmea__persistency__err_handl, feat_saf_fmea__persistency__late_message, feat_saf_fmea__persistency__msg_not_received, feat_saf_fmea__persistency__not_sent
feat_arc_dyn__persistency__snapshot_restore		Feature Sequence Diagram

Logical Interfaces

The logical interfaces of the feature are defined in the platform documentation: Ikvs (logic_arc_int__persistency__interface).

See SCORE Features for more information.

Used Components

The feature is realized by the following components of the module:

• persistency::kvs (comp__persistency_kvs)