DALP Execution Engine
The DALP Execution Engine orchestrates digital asset lifecycle operations with guaranteed delivery, automatic retry handling, and transparent failure recovery, ensuring complex multi-step processes complete reliably even through system failures.
Overview
The DALP Execution Engine coordinates multi-step operations across platform components. Workflows persist at each step, enabling reliable completion despite process restarts, network failures, or partial execution errors.
Blockchain operations present unique orchestration challenges. Transaction confirmation requires minutes rather than milliseconds. Gas prices fluctuate unpredictably. Nonce conflicts occur under concurrent load. The DALP Execution Engine addresses these realities through purpose-built workflow patterns.
The challenge of blockchain orchestration
Traditional request-response patterns fail for blockchain operations. A single asset issuance may require:
- Verify investor eligibility
- Deploy token contract
- Wait for deployment confirmation
- Configure compliance rules
- Mint initial supply
- Register with identity provider
- Notify stakeholders
Each step can fail independently. Steps 2-5 involve blockchain transactions that may take minutes. Naive implementations lose state if the process restarts between steps.
Workflow patterns
Persistent state machines
Every workflow maintains persistent state that survives process boundaries. State transitions record to storage before execution proceeds. Restart recovery reads last persisted state and continues from that checkpoint.
Exactly-once semantics
Workflow steps execute exactly once regardless of retries or restarts. Unique operation identifiers prevent duplicate blockchain transactions. Idempotency keys ensure side effects occur only on first execution.
Virtual object pattern
Long-running entities like transaction nonces maintain consistent state through virtual objects. Concurrent access serializes through the execution engine. No distributed locking or coordination protocols required.
Workflow architecture
Failure recovery
Automatic retry
Transient failures trigger automatic retry with exponential backoff. Retry policies configure per-operation based on expected failure patterns. Blockchain transaction retries increment gas prices to resolve stuck transactions.
Compensating transactions
Permanent failures trigger compensating workflows. If token minting fails after contract deployment, the engine initiates contract pause and investor notification workflows. Partial state never persists without explicit handling.
Dead letter handling
Operations exhausting retry budgets route to dead letter queues. Operations teams receive alerts for manual intervention. Replay mechanisms enable resumption after root cause resolution.
Observability
The engine provides complete visibility into workflow execution:
State inspection: Current state and history for any workflow instance accessible through administrative interfaces.
Distributed tracing: Correlation identifiers flow through all workflow steps. Trace spans capture timing and outcomes for performance analysis.
Progress dashboards: Real-time views of active workflows by type and state. Bottleneck identification through queue depth monitoring.
Audit logs: Every state transition records for compliance review. Retention policies ensure availability for regulatory examination periods.
See also
- Transaction Signer for blockchain operations
- Key Guardian for secure key storage
- Observability for monitoring dashboards
- Unified API for API entry point
- Asset Console for UI entry point
Overview
The infrastructure layer contains the backend services that orchestrate workflows, manage cryptographic keys, sign transactions, index blockchain events, and provide network connectivity. These services are not accessed directly by users -- they operate behind the platform interfaces.
Key Guardian
The Key Guardian service manages cryptographic key material with defense-in-depth security, supporting encrypted database storage, secret managers, hardware security modules, and third-party custody providers including DFNS and Fireblocks.