Glossary

Standard error

The diagnostic stream separate from stdout results. The exit status still indicates command success/failure.

Standard output

The normal program-output stream, distinct from stderr. Useful in CLI checks/pipelines; do not print secrets here either.

Start barrier

A test synchronization point where tasks wait for a common start. It helps exercise competing attempts but does not protect business data or guarantee a particular transaction order.

State machine

A model of states and allowed transitions triggered by events or operations. Distinguish invalid transitions, repeated operations and events arriving too late.

State pattern

An object delegates operations to its current state object. This is one implementation of a state machine; enum/switch may be simpler. It provides no database locking.

StatefulSet

Manages Pods with stable identity and volume association. It does not automatically add database replication, backups or high availability.

StorageClass

Describes dynamic volume provisioning. Parameters are provider-specific; an identical class name in two clusters does not guarantee identical behavior.

Strategy pattern

Separating interchangeable ways of performing a task behind a common contract. Useful when behaviours evolve independently; a simple conditional does not always need this pattern.

Structural typing

Type compatibility based on required members without a declared common ancestor. It does not prove compatible behaviour.

Structured output

Output constrained to a defined schema such as JSON. It helps validate syntax and fields, while application code still checks domain rules and execution safety.

Subnet

An address range within a network. An AWS subnet belongs to one availability zone. Public reachability depends on routes and addressing, not a name containing public.

Swoole

A PHP extension offering servers and concurrency mechanisms. Coroutines alone do not guarantee nonblocking behaviour for every I/O client.

Symfony

An ecosystem of PHP components and a framework that assembles them. Small labs can use components alone; that is not the same as a complete framework application.

Sync wave and hook

Argo CD synchronization phases and ordering. Phase takes precedence over wave; a Job’s dependencies must exist at the right time. Hooks do not run during selective sync.

Syntax

Rules for writing statements, expressions and blocks. Valid syntax does not prove that the program implements the correct business rule.

Task group

A scope managing concurrent tasks and awaiting their completion. In asyncio, a non-cancellation failure normally cancels remaining tasks and collects exceptions.

TDD

TDD

Test-Driven Development

A cycle of a failing behaviour test, minimal implementation and refactoring. Writing a test first does not by itself ensure good design or risk coverage.

Template Method

A base-class algorithm leaves selected steps to subclasses. It shares a skeleton while coupling extensions to inheritance and the base contract.

Tenant

An organization or customer whose data is separated from others. Verify resource ownership on every operation; knowing an identifier does not grant access.

Terraform

A tool managing declared resources through providers and state. State files may contain sensitive data; a plan is not authorization to apply changes automatically.

Test assertion

A check of a specific expectation in a test, such as a result equal to 7 or an HTTP response with status 422. An unmet expectation fails the test. One test can contain several assertions; their count does not establish coverage quality. A test assertion is different from validating user input.

Test fixture

A mechanism supplying test data/resources and arranging cleanup. Lifetime scope matters: a shared mutable fixture can make results depend on test order.

Testcontainers

Libraries starting disposable container services for integration tests. They provide real engines but require a suitable container runtime.

Thread pool

A set of threads executing submitted tasks. Moving work off an event loop requires explicit submission or a framework mechanism; an ordinary helper call is insufficient. Bound the queue and workers; a pool does not provide rollback.

Threat model

A description of assets, trust boundaries, plausible abuse and verified controls for a specific design. It does not replace testing or a full security audit.

Throughput

RPS

Requests Per Second

TPS

Transactions Per Second

Completed units of work per time. State whether you count requests, transactions or business effects; fast failures are not successful throughput.

Time to live

TTL

Time To Live

A validity-time limit for an entry, message or configuration. Expiry need not immediately delete data or prove a newly fetched value is current.

Timeout — waiting limit

A timeout limits waiting; a deadline marks the end of the total time budget. No response does not prove that a remote operation did not happen.

TLS

TLS

Transport Layer Security

A protocol protecting communication against eavesdropping and tampering and supporting peer verification. It does not replace application authorization or endpoint data controls.

Tool permissions

The operations and resources an application permits a tool or its user to access. A model proposal or document text does not expand this set. Check permission before executing the operation.

An assistant may read a test report but may not read a production secret or run a terminal command.