🦚 Peacock Unified

🏗️ App Invariants

Layer 2 — application architecture · 1,820 documents

IDDocumentSource
app_invariants__556381b14e28f0c2INVARIANT: API capability negotiation must resolve to the strict intersection of supported version ranges. SHADOW: Nodes in a distributed cluster communicate using diverse software versions. The…—
app_invariants__76f67d2fa968730bINVARIANT: Transactional end-states require explicit Producer ID and Epoch binding to neutralize 'Zombie' producers. SHADOW: In a distributed transaction, a delayed request from an old leader or…—
app_invariants__5df374ade0dd39d8INVARIANT: Memory allocation for network buffers must be bounded by a pool with hard limits and proactive reclamation. SHADOW: Under heavy load, unbounded object creation for incoming requests leads…—
app_invariants__f3a1df81a2742d79INVARIANT: Exception handling must distinguish between 'Transient Retriable' and 'Metadata-Refresh Retriable' states. SHADOW: Retrying a request blindly can lead to infinite loops. The system…—
app_invariants__4e64ffe94bd706ccINVARIANT: Internal timers must enforce non-monotonicity protection to prevent deadline corruption. SHADOW: System clocks can drift or be reset. Software timers (Timer utility) must internally…—
app_invariants__5f0b3ce8de6216d8INVARIANT: Zero-copy serialization must prioritize buffer slicing over data duplication to maintain throughput linearity. SHADOW: Copying bytes between buffers during message framing consumes CPU…—
app_invariants__58d317e1aac66a89INVARIANT: Certificate generation methods MUST produce valid X509 certificates with correct validity periods and distinguished names. SHADOW: Ensures that generated certificates are structurally…—
app_invariants__416e0b4e80d8b1cfINVARIANT: Key stores and trust stores MUST be correctly initialized, populated, and saved to disk or memory with specified passwords. SHADOW: Guarantees the integrity and accessibility of…—
app_invariants__fd21b54532a7e619INVARIANT: SSL configuration maps MUST consistently define all necessary parameters for SSLContext creation and management. SHADOW: Ensures that the SSL/TLS handshake process has all required…—
app_invariants__9f4c6a4f3e54bb54INVARIANT: Conversion to PEM format MUST correctly export and, if requested, encrypt private keys and export certificate chains. SHADOW: Ensures that cryptographic material is represented in a…—
app_invariants__5b765467ef6609adINVARIANT: The CertificateBuilder MUST correctly handle Distinguished Names (DNs) and associate them with generated certificates. SHADOW: Ensures that each certificate has a unique and correctly…—
app_invariants__46b8c3591c914389INVARIANT: Certificate generation MUST correctly apply signing algorithms and use appropriate key parameters for signature generation. SHADOW: Ensures the cryptographic integrity of certificates…—
app_invariants__24067dd44fb9841cINVARIANT: Subject Alternative Names (SANs) MUST be correctly encoded and added to certificates when provided. SHADOW: Enables certificates to be valid for multiple hostnames or IP addresses,…—
app_invariants__0c65b9f3675e957dINVARIANT: The SSL configuration builder MUST correctly create JKS or PEM formatted configurations based on the `usePem` flag. SHADOW: Provides flexibility in how SSL configurations are generated,…—
app_invariants__c70ad408dcaf105eINVARIANT: Key stores MUST be created with the correct alias, private key, certificate chain, and passwords. SHADOW: Ensures that private keys and their associated certificates are securely stored…—
app_invariants__e3d9cd4eb57ababcINVARIANT: Trust stores MUST be created by adding certificate entries with their respective aliases. SHADOW: Establishes the set of trusted root certificates, enabling the validation of certificate…—
app_invariants__06c6167c524254e3INVARIANT: Lifecycle State Transition Monotonicity SHADOW: The KafkaStreams.State enum defines a directed graph of valid transitions. This prevents illegal operations like shutting down a service…—
app_invariants__e3fa74ac3205415cINVARIANT: Window Retention Sufficiency Constraint SHADOW: In WindowStoreMaterializer and SlidingWindowStoreMaterializer, the retention period must be strictly greater than or equal to the window…—
app_invariants__3c180d4ee1dcd11fINVARIANT: Causal Consistency via Position Bounds SHADOW: The Position and PositionBound classes track offsets across multiple topics and partitions. Queries against state stores (StateQueryRequest)…—
app_invariants__2e828be48cf0bdd4INVARIANT: Null-Key/Value Exclusion in Stateful Aggregates SHADOW: In KStreamAggregate and KStreamReduce, records with null keys or null values are explicitly dropped and recorded via a…—
app_invariants__fe8421945f2de757INVARIANT: Change-Log Propagation (Old Value Preservation) SHADOW: KTable operations (like KTableSource and KTableReduce) support 'enableSendingOldValues'. This is necessary for downstream joins and…—
app_invariants__3d870bd4c1fa156dINVARIANT: Temporal Grace Period Enforcement SHADOW: The AbstractKStreamTimeWindowAggregateProcessor drops records where the timestamp is older than the 'observedStreamTime - gracePeriod'. This acts…—
app_invariants__ddd07acf077c224eINVARIANT: Topology Dependency Ordering SHADOW: The GraphNode.writeToTopology method requires that all parent nodes are written to the topology before child nodes. This ensures that the physical…—
app_invariants__6db40560f2eb2a11INVARIANT: Repartitioning Necessity for Key-Space Alignment SHADOW: Operations like KGroupedStreamImpl and KGroupedTableImpl trigger a repartitioning phase (creating a sink and source for a…—
app_invariants__f32a0b6c51e6b362INVARIANT: Checkpoint updates must utilize a temporary-file-write followed by an atomic filesystem move to prevent state corruption during process crashes. SHADOW: If a crash occurs during a direct…—
app_invariants__91dfccc432c31372INVARIANT: Suppression buffers must enforce hard limits on record count or byte size, triggering either a terminal shutdown or an eager emission to protect the JVM heap. SHADOW: Unbounded…—
app_invariants__3501e1246a76b4c9INVARIANT: Versioned state stores must reject 'out-of-order' writes where the record timestamp is older than the current stream time minus the defined grace period. SHADOW: In a temporal database,…—
app_invariants__3d54be9a49ed6899INVARIANT: State stores must maintain a 1:1 mapping between local disk segments and changelog offsets to ensure recovery is resume-able rather than restart-able. SHADOW: By checkpointing the…—
app_invariants__d34021853e221a0bINVARIANT: The ThreadCache must implement a global memory-pressure-driven eviction policy across all named caches using a circular iterator to maintain a fixed memory footprint. SHADOW: Since…—
app_invariants__f46edd2dd5c9fd25INVARIANT: Foreign key join responses must encapsulate the hash of the original primary-side value to detect and discard stale join results caused by rapid primary-key updates. SHADOW: Because FK…—
app_invariants__5ecb051404c8a3feINVARIANT: Segmented stores must automatically purge data segments whose maximum timestamp is older than the current stream time minus the retention period. SHADOW: This is the 'physics' of windowed…—
app_invariants__bb039c903ff38a31INVARIANT: Task-Shard Isolation Exclusivity SHADOW: Sharing a state store shard across sibling tasks or different transformer instances triggers immediate data corruption. The system enforces a…—
app_invariants__dc834d2c061e98a2INVARIANT: Active Task Singleton Enforcement SHADOW: A specific Task ID must never be assigned as ACTIVE to more than one client simultaneously. Validation logic in the assignment phase prevents…—
app_invariants__e62489265fe07ecbINVARIANT: Restoration Callback Non-Blocking Invariant SHADOW: State restoration batching requires minimal processing latency within listener callbacks. Heavy logic in 'onBatchRestored' creates…—
app_invariants__a72a6b6ad33a0130INVARIANT: File-System Level Process Locking SHADOW: Persistence directories are guarded by physical file locks (.lock). This neutralizing race conditions where multiple Kafka Streams instances on…—
app_invariants__097467a9e3596bceINVARIANT: Punctuation Re-entrancy Suppression SHADOW: Punctuation schedules (STREAM_TIME or WALL_CLOCK_TIME) must skip missed intervals if the previous iteration hasn't completed or if time jumps…—
app_invariants__ae5d5bc831e577e0INVARIANT: Co-partitioning Symmetry Constraint SHADOW: Joined source topics must strictly share identical partition counts. If partition counts diverge, the topology builder must fail immediately to…—
app_invariants__2c899f6b70879d25INVARIANT: Standby Task Monotonic Update Invariant SHADOW: Standby tasks only advance state via changelog consumption and are forbidden from committing offsets. They exist in a perpetual 'RESTORING'…—
app_invariants__726786750e280e6eINVARIANT: Checkpoint-Flush Order Atomicity SHADOW: Local state checkpoints must only be written AFTER a successful flush of the state store and potential producer commit. Writing a checkpoint for…—
app_invariants__eee90170fdf1f4e1INVARIANT: The foundational record context (timestamp, offset, topic, partition, headers) once constructed, MUST remain immutable throughout its processing pipeline within a ProcessorRecordContext…—
app_invariants__b5feea3ef7adfb14INVARIANT: All read and write operations to the shared collections of active, standby, paused, restored, and pending tasks MUST be protected by explicit locks and condition variables. SHADOW: This…—
app_invariants__daa45a380698e6bfINVARIANT: All asynchronous exceptions originating from producer callbacks or other background operations MUST be captured atomically and subsequently re-thrown in the main processing thread or…—
app_invariants__922469544f8a7b85INVARIANT: The StreamThread MUST adhere to a strictly defined finite state machine for its lifecycle, ensuring that transitions between states are explicit, validated, and prevent illegal…—
app_invariants__242106f16e331ca8INVARIANT: For tasks operating with Exactly-Once Semantics (EOS), the local state checkpoint file MUST be explicitly deleted upon task resume() operation. SHADOW: This deletion prevents the…—
app_invariants__4ac278eeb8d7f9faINVARIANT: During task assignment, each input topic partition MUST be assigned to exactly one active task, and all source topic partitions for a given topology MUST be accounted for. SHADOW: This…—
app_invariants__9e51d257201a0208INVARIANT: During a cooperative rebalance, an active task whose ownership is changing to another consumer instance MUST NOT be immediately reassigned to its new owner if it is still owned by the old…—
app_invariants__9aa42d7e66b17d39INVARIANT: Any operation involving simultaneous access or modification of multiple shared task queues across different contexts MUST acquire locks in a consistent, predefined order to prevent…—
app_invariants__b947dc598929712fINVARIANT: Each input topic partition's record queue MUST enforce a maximum buffered size, and exceeding this limit MUST trigger a pause in consumer polling for that specific partition. SHADOW: This…—
app_invariants__28f073ff403b5acfINVARIANT: During task shutdown or failure, all registered state stores MUST be closed, flushed, and their underlying resources released, with proper exception handling to ensure that all stores are…—
app_invariants__3524986fab861822INVARIANT: Global State Management must occur within a single-instance lock scope per application identity. SHADOW: Global state consistency in distributed stream processing relies on serialized…—