Glossary
Search Azure terms
Open a clear definition, then continue into exam context, architecture, commands, operational examples, common mistakes, and related concepts.
Search all
Commands
Learning guides
Concept graph
Compare
Search-first Azure knowledge base
Term results
Search for a term or click a category. Results render only after you ask for them, so the glossary does not dump every available term on first load. Each result includes Quick peek and Open full term page actions.
Start with a search or a category.
Try managed identity , resource group , az group , private endpoint , or click Databases to load all database-related terms.
Showing 50 of 56 matching terms. Narrow the search to reduce the list.
Databases
premium
Autoscale throughput
Autoscale throughput is Azure Cosmos DB’s way to adjust request-unit capacity for a database or container as traffic changes. In plain terms, you set a maximum RU/s value, and Cosmos DB scales within that range instead of forcing you to pick one fixed manual throughput number. It is useful for workloads with bursts, uneven schedules, or.
Azure Cosmos DB
intermediate
4 commands
Aliases: Cosmos DB autoscale throughput, autoscale RU/s, autoscale provisioned throughput, max RU/s
Quick peek
Open full term page
Containers
premium
AKS horizontal pod autoscaler
The AKS Horizontal Pod Autoscaler is the Kubernetes HPA capability used in AKS to automatically change the number of pod replicas for a workload based on observed metrics such as CPU, memory, or custom metrics.
Azure Kubernetes Service scaling
intermediate
3 commands
Aliases: HPA on AKS, horizontal pod autoscaler, Kubernetes HPA, pod autoscaling
Quick peek
Open full term page
Analytics
learning-path-anchor
Synapse Spark pool
A Synapse Spark pool is the workspace compute definition Azure Synapse uses to start Apache Spark sessions. It records node size, node count, autoscale behavior, runtime version, packages, and idle timeout so notebooks, Spark jobs, and pipelines get repeatable distributed processing.
Synapse Analytics
fundamentals
8 commands
Aliases: Apache Spark pool, Spark pool, Synapse Apache Spark pool, serverless Spark pool
Quick peek
Open full term page
Monitoring and Observability
learning-path-anchor
Throughput
Throughput is the amount of work a system completes over time, such as requests, messages, bytes, events, or transactions per second. In Azure, teams measure it with service metrics, logs, and capacity settings to judge whether an app, database, storage account, or messaging pipeline can sustain demand.
Performance
intermediate
4 commands
Aliases: Throughput, throughput, Azure Throughput, Microsoft Learn Throughput, requests per second, events per second, transactions per second, bytes per second, work completed over time
Quick peek
Open full term page
Databases
premium
Cosmos DB provisioned throughput
Cosmos DB provisioned throughput means the request-unit-per-second capacity reserved for a database or container, either manually or with autoscale behavior in Azure Cosmos DB. In plain English, it is the thing developers and operators check when they need to understand how data access really works. It connects the application model to capacity planning, throttling prevention, RU allocation, cost control, and predictable performance for operational workloads. For a production team, it turns vague database talk into a specific thing to inspect in the portal, SDK code, templates, metrics, and incident notes.
Azure Cosmos DB
intermediate
7 commands
Aliases: No aliases yet
Quick peek
Open full term page
Databases
premium
Cosmos DB serverless
Cosmos DB serverless is the Cosmos DB capacity mode that bills for request units consumed and storage used instead of pre-provisioned RU/s. It lets intermittent or unpredictable workloads use Cosmos DB without reserving throughput all day. You see it when a new account is created, a workload has bursty usage, or a team compares serverless with provisioned throughput. The production check is whether consumption billing, throughput limits, regional design, and workload shape fit the production objective. Document the decision in code, templates, metrics, and runbooks.
Azure Cosmos DB
intermediate
6 commands
Aliases: No aliases yet
Quick peek
Open full term page
Compute
premium
Flexible orchestration
Flexible orchestration is a Virtual Machine Scale Sets mode that lets Azure manage a group of VMs while exposing individual instances through standard Azure IaaS VM APIs. Teams use it to run highly available or mixed virtual machine workloads that need scale-set grouping, instance-level VM control, spreading, load balancing, and more flexible lifecycle management than uniform orchestration. It is not an autoscale rule by itself, a way to change an existing scale set orchestration mode after creation, a replacement for application failover, or a guarantee that every VM size supports every feature.
Virtual Machine Scale Sets
intermediate
6 commands
Aliases: VMSS flexible orchestration, Flexible scale set orchestration, Azure VM Scale Sets flexible mode
Quick peek
Open full term page
Web
premium
App Service scale rule
App Service scale rule is an autoscale rule or automatic scaling configuration that changes App Service capacity when metric thresholds, schedules, or platform load signals require more or fewer instances. Use it to reason about App Service behavior, validate configuration with CLI, and prevent hidden production impact from networking, scaling, recovery, security, or observability changes.
App Service Scaling
intermediate
5 commands
Aliases: No aliases yet
Quick peek
Open full term page
Virtual Desktop Infrastructure
premium
Azure Virtual Desktop
Azure Virtual Desktop is a desktop and app virtualization service that runs on Azure, delivering Windows desktops and RemoteApp experiences with host pools, session hosts, and flexible control.
Virtual desktops
fundamentals
5 commands
Aliases: AVD
Quick peek
Open full term page
Containers
premium
Container Apps replica
a running instance of a Container Apps revision that is added or removed as Azure Container Apps scales the workload
Azure Container Apps
intermediate
5 commands
Aliases: No aliases yet
Quick peek
Open full term page
Databases
premium
Cosmos DB throughput
Choose container-level throughput for a critical workload that must not be slowed by noisy neighboring containers.; Use autoscale for predictable daily traffic spikes where manual RU changes create operational risk.
Azure Cosmos DB
intermediate
5 commands
Aliases: RU/s, Cosmos DB throughput
Quick peek
Open full term page
Monitoring and Observability
premium
HTTP queue length
HTTP queue length is an App Service plan metric that shows the average number of HTTP requests waiting in the queue before being fulfilled.
Azure App Service
intermediate
5 commands
Aliases: HTTP queue length, http queue length
Quick peek
Open full term page
Web
premium
Shared App Service tier
The Shared App Service tier is a base App Service plan option where apps run on shared Azure virtual machines and receive CPU-minute quotas. It is intended for development and testing, not production workloads that need dedicated compute, autoscale, or predictable performance isolation.
App Service plans
intermediate
5 commands
Aliases: App Service Shared tier, Shared App Service plan, D1 App Service plan, shared compute App Service, App Service D1
Quick peek
Open full term page
Databases
premium
Shared database throughput
Shared database throughput in Azure Cosmos DB means RU/s are provisioned at the database level and shared by containers in that database. Microsoft recommends container-level throughput for most workloads because shared throughput can create unpredictable performance and scale behavior across containers.
Azure Cosmos DB
intermediate
5 commands
Aliases: Cosmos DB shared database throughput, database-level throughput, shared RU/s database, Cosmos DB database throughput, shared throughput database
Quick peek
Open full term page
Web
premium
App Service
Azure App Service is a managed HTTP-based platform for hosting web apps, REST APIs, and mobile back ends without managing the underlying servers. It helps learners understand where the concept appears in Azure operations and what to verify before changing it.
App Service
intermediate
4 commands
Aliases: App Service, app service
Quick peek
Open full term page
Integration
premium
Auto-inflate
Auto-inflate is Azure Event Hubs’ way to add more Standard tier throughput capacity when traffic grows. In plain terms, you set the namespace’s normal throughput units and an upper limit, and Event Hubs can increase capacity during busy periods. This helps absorb spikes without a person watching the portal every minute. It is especially.
Event Hubs
intermediate
4 commands
Aliases: Event Hubs Auto-inflate, Event Hubs auto inflate, throughput unit auto scale, Event Hubs throughput scaling
Quick peek
Open full term page
Databases
premium
Azure Cosmos DB
Azure Cosmos DB is a fully managed database service for NoSQL, relational, and vector workloads. It supports global distribution, elastic scale, multiple APIs, request-unit capacity, backup, and high availability so modern applications can store and query data without operating database servers.
Azure Cosmos DB
fundamentals
4 commands
Aliases: Azure Cosmos DB, Cosmos DB, Azure Cosmos DB for NoSQL, Cosmos database, global NoSQL database, request-unit database
Quick peek
Open full term page
Databases
premium
Azure Cosmos DB for NoSQL
The native document database API of Azure Cosmos DB for JSON data, SQL-like queries, partitioning, indexing, and scalable request-unit throughput.
Azure Cosmos DB
intermediate
4 commands
Aliases: Cosmos DB NoSQL API, Azure Cosmos DB SQL API
Quick peek
Open full term page
Databases
premium
Cosmos DB query
Find the high-RU query that causes 429 throttling before increasing provisioned throughput or autoscale limits.; Decide whether a user-facing search should remain a Cosmos DB query, become a point-read pattern, or move t
Azure Cosmos DB
intermediate
4 commands
Aliases: Cosmos DB query, cosmos db query
Quick peek
Open full term page
Containers
premium
CPU scale rule
an autoscale rule that adds or removes running instances when CPU usage crosses a defined threshold for a sustained window.
Autoscale
intermediate
4 commands
Aliases: CPU autoscale rule, Percentage CPU scale rule, Autoscale CPU rule
Quick peek
Open full term page
Databases
premium
Dedicated throughput container
A dedicated throughput container is an Azure Cosmos DB container with throughput provisioned directly on that container instead of sharing database-level throughput with other containers.
Cosmos DB
intermediate
4 commands
Aliases: dedicated container throughput, container-level throughput, Cosmos DB dedicated throughput container
Quick peek
Open full term page
Web
premium
Functions scale controller
Functions scale controller is the Azure Functions component that watches trigger workload signals and decides how many app instances should run. Teams use it to match serverless capacity to event demand without manually adding workers for every queue, event stream, timer, or HTTP workload. In daily Azure work, it appears when engineers investigate backlog growth, explain unexpected scale-out, tune trigger concurrency, enable scale logs, or decide whether Premium capacity is necessary. It is not an application scheduler, a guaranteed throughput contract, a replacement for downstream capacity, or a setting that can fix inefficient function code by itself.
Azure Functions scaling
advanced
4 commands
Aliases: Azure Functions scale controller, scale controller, Functions autoscale controller
Quick peek
Open full term page
Containers
premium
Minimum replicas
Minimum replicas is the lowest number of running replicas a scale controller or platform should maintain for a workload. Teams should manage it with clear ownership, monitoring, rollback evidence, and production change discipline.
Azure Container Apps
intermediate
4 commands
Aliases: Container Apps minimum replicas, min replicas, minReplicas, scale floor
Quick peek
Open full term page
AI and Machine Learning
premium
Compute cluster
a managed Azure Machine Learning pool of CPU or GPU nodes that runs training, batch inference, and other jobs for a workspace
Machine learning
Intermediate
3 commands
Aliases: No aliases yet
Quick peek
Open full term page
Web
premium
CPU percentage
CPU percentage is an Azure glossary term for a platform metric that shows how much processor capacity an app, plan, virtual machine, or scale set is using over time. In practice, it helps teams reason about detecting compute pressure, validating scale rules, investigating latency, and deciding whether code, plan size, or instance count must change using live Azure evidence, documented ownership, and Microsoft Learn guidance. It should be reviewed through security, reliability, operations, cost, and performance lenses before production changes.
Azure Monitor metrics
beginner
3 commands
Aliases: Cpu percentage, CpuPercentage, Percentage CPU, CPU utilization
Quick peek
Open full term page
Storage
premium
Approximate message count
Approximate message count is the queue-depth estimate you use when checking whether an Azure Storage queue is backing up, draining normally, or ready for scale decisions. It is not a perfect inventory of every message; it is a practical signal for operations. Teams use it to decide whether workers are falling behind, whether a.
Queue Storage
fundamentals
2 commands
Aliases: ApproximateMessagesCount, Queue approximate message count, x-ms-approximate-messages-count, Queue depth estimate
Quick peek
Open full term page
Databases
verified
Request Unit
In Azure Cosmos DB, a request unit is the normalized measure of resource cost for database operations. Reads, writes, and queries consume RUs, and provisioned throughput is expressed as RU/s so teams can plan performance and cost consistently across APIs and workloads. across APIs.
Cosmos DB
fundamentals
6 commands
Aliases: RU, RU/s, Cosmos DB request unit, request unit charge, Cosmos throughput currency
Quick peek
Open full term page
Web
verified
Requests in application queue
Requests In Application Queue is an Azure Monitor metric for Microsoft.Web/sites that reports how many Web App or Function App requests are waiting in the application request queue. It helps diagnose saturation, slow handlers, cold starts, thread exhaustion, or delayed scale-out.
Web App metric
intermediate
6 commands
Aliases: RequestsInApplicationQueue, App Service application queue, HTTP requests in application queue, Web App request queue metric, Function App request queue metric
Quick peek
Open full term page
App platform
verified
Worker instance
In Azure App Service, a worker instance is one compute instance in the App Service plan that can run hosted apps. Scaling out increases the number of instances, while plan SKU and platform settings determine available CPU, memory, and scale limits.
App Service
fundamentals
6 commands
Aliases: App Service worker, App Service instance, web app instance, worker VM instance
Quick peek
Open full term page
Web
field-manual-complete
Premium v3 App Service tier
Premium v3 is a higher App Service plan tier for apps that need more dedicated compute, memory, or scale than lower tiers provide.
App Service plans
intermediate
5 commands
Aliases: No aliases yet
Quick peek
Open full term page
Management and Governance
verified
Resource delete protection
Resource delete protection uses Azure management locks, usually CanNotDelete, to stop critical resources or resource groups from being deleted by ordinary control-plane operations.
Management locks
fundamentals
5 commands
Aliases: Azure delete protection, management lock delete protection, CanNotDelete lock, delete lock, protected Azure resource
Quick peek
Open full term page
Analytics
field-manual-complete
Streaming unit
A streaming unit is the capacity dial for an Azure Stream Analytics job. When the job needs more compute and memory to keep up with input events, you adjust streaming units rather than managing servers. More SUs can help a job process higher volume, but they are not magic. The query must be able to use the capacity, the inputs need useful partitioning, and the outputs must keep up. Operators treat SUs as a cost and performance lever that must be measured, not guessed.
Streaming analytics
fundamentals
5 commands
Aliases: Azure Stream Analytics streaming unit, Stream Analytics SU, SUs, streaming units
Quick peek
Open full term page
Compute
field-manual-complete
Uniform orchestration
Uniform orchestration is a Virtual Machine Scale Sets mode where Azure creates and manages a set of mostly identical VM instances from one scale set model. It is suited to stateless, homogeneous fleets that need centralized scaling, upgrades, health, and instance management through the VMSS resource.
Virtual Machine Scale Sets
intermediate
5 commands
Aliases: VMSS Uniform orchestration, uniform VM scale set, Virtual Machine Scale Sets Uniform mode, orchestration mode Uniform
Quick peek
Open full term page
Compute
field-manual-complete
Virtual machine scale set
A managed group of VM instances that can scale and update as a fleet.
Azure Virtual Machine Scale Sets
intermediate
5 commands
Aliases: VM scale set, Azure VMSS, Virtual Machine Scale Set, scale set, virtual machine scale set
Quick peek
Open full term page
Compute
verified
VM scale set instance
A VM scale set instance is an individual virtual machine that belongs to an Azure Virtual Machine Scale Set. Operators can inspect, restart, reimage, update, delete, or run commands against specific instances while the scale set manages the broader group model.
Virtual Machine Scale Sets
intermediate
5 commands
Aliases: VM scale set instance, vm scale set instance
Quick peek
Open full term page
Databases
template-specs-upgraded
RU per second
Microsoft Learn explains that Azure Cosmos DB provisioned throughput is assigned on a per-second basis in request units. RU per second represents the throughput reserved for a database or container, can be scaled, and is billed hourly in provisioned mode.
Azure Cosmos DB
intermediate
5 commands
Aliases: request units per second, RUs per second, Cosmos throughput rate, provisioned RU rate, Cosmos DB RU per second
Quick peek
Open full term page
Databases
template-specs-upgraded
RU/s
Microsoft Learn uses RU/s as the abbreviation for request units per second in Azure Cosmos DB. It describes provisioned throughput allocated to a database or container, including manual and autoscale modes, and is central to performance, throttling, and billing decisions.
Azure Cosmos DB
fundamentals
5 commands
Aliases: RUs, request units per second, Cosmos DB RU/s, throughput RU/s, provisioned throughput RU/s
Quick peek
Open full term page
Web
template-specs-upgraded
Scale out
Scale out means adding more running instances of an App Service plan or app so traffic is spread across additional workers.
App Service
intermediate
5 commands
Aliases: horizontal scale, App Service scale out, automatic scaling, instance count, elastic scale
Quick peek
Open full term page
Databases
complete
Shared throughput database
A Cosmos DB database whose containers share provisioned request units from one database-level throughput pool.
Cosmos DB
intermediate
5 commands
Aliases: Cosmos DB shared throughput database, database-level throughput, shared database throughput, database RU/s pool
Quick peek
Open full term page
Analytics
complete
Spark pool
Microsoft Learn defines a Synapse Spark pool as a serverless Apache Spark pool definition that creates Spark instances when sessions or jobs run. Its settings control node size, scaling behavior, runtime, and time to live while data remains stored outside the pool.
Analytics platform
fundamentals
5 commands
Aliases: Synapse Spark pool, Apache Spark pool, serverless Spark pool, Synapse Apache Spark compute
Quick peek
Open full term page
Web
complete
Standard App Service tier
Microsoft Learn describes App Service plan tiers as the compute and feature boundary for apps hosted in Azure App Service. The Standard tier is a production-oriented tier that supports capabilities such as custom domains, TLS, autoscale, deployment slots, and larger dedicated capacity than entry-level tiers.
App Service plans
intermediate
5 commands
Aliases: standard-app-service-tier, Standard App Service tier, App Service Standard tier, Standard App Service plan, S1 App Service plan, S2 App Service plan
Quick peek
Open full term page
App platform
verified
Per-site scaling
Per-site scaling lets apps in the same App Service plan use different numbers of workers. Normally, when a plan scales out to five instances, every app in that plan can run on all five. With per-site scaling enabled, one quiet app might use one worker while a busy app uses four. This is useful when many related apps share a paid plan but do not need equal capacity. It is not autoscale by itself; it is a placement and worker-count control.
App Service
intermediate
4 commands
Aliases: per-app scaling, PerSiteScaling, App Service per-app scaling, per site scaling, high-density App Service scaling
Quick peek
Open full term page
Databases
premium field-manual
Manual throughput
Manual throughput is a Cosmos DB throughput mode where teams set a fixed RU/s value instead of using autoscale. Teams use it when a database or container has predictable traffic and operators want explicit request-unit capacity. In plain English, it gives operators a named control for controlled RU/s spending, predictable capacity, and simpler throughput evidence for steady workloads instead of leaving the decision hidden in a portal setting, script, or deployment file. Treat it as production-ready only when the owner, dependencies, permission boundary, monitoring signal, and rollback evidence are clear.
Azure Cosmos DB
intermediate
4 commands
Aliases: Manual throughput, Azure Cosmos DB, autoscale throughput, serverless capacity mode, provisioned throughput, standard throughput, fixed RU/s, Azure Cosmos DB provisioned throughput
Quick peek
Open full term page
Web
premium field-manual
Memory percentage
The memory percentage metric is a memory utilization value that shows how much of a container or workload memory allocation is being used. Teams use it when operators need to detect memory pressure, tune limits, or drive memory-based scaling decisions. In plain English, it gives operators a named control for earlier visibility into memory-bound behavior, restarts, and capacity risk instead of leaving the decision hidden in a portal setting, script, or deployment file. Treat it as production-ready only when the owner, dependencies, permission boundary, monitoring signal, and rollback evidence are clear.
App Service and Azure Monitor metrics
intermediate
4 commands
Aliases: Memory percentage, MemoryPercentage, memory utilization percentage, memory metric, memory usage percentage, container memory percentage, App Service memory percent, Azure Monitor and Azure App Service, App Service and Azure Monitor metrics
Quick peek
Open full term page
Containers
premium field-manual
Memory scale rule
A memory scale rule is a Container Apps scale rule that uses memory utilization to add or remove running replicas within configured limits. Teams use it when a container workload becomes memory-bound before HTTP traffic, CPU, or queue length fully explains pressure. In plain English, it gives operators a named control for pressure-based scaling for memory-sensitive services while keeping replica bounds visible instead of leaving the decision hidden in a portal setting, script, or deployment file. Treat it as production-ready only when the owner, dependencies, permission boundary, monitoring signal, and rollback evidence are clear.
Azure Container Apps scaling
intermediate
4 commands
Aliases: Memory scale rule, memory autoscale rule, KEDA memory trigger, Container Apps memory scale, memory utilization scale rule, KEDA memory rule, memory based scale rule, KEDA memory scaler, Container Apps memory scaling, Azure Container Apps and KEDA autoscaling, Azure Container Apps scaling
Quick peek
Open full term page
Compute
template-specs-upgraded
Scale set capacity
Microsoft Learn describes Virtual Machine Scale Set capacity as the instance count declared for a scale set. Operators can manually change sku.capacity or let autoscale rules adjust it, but each capacity decision affects compute cost, load-balancer health, zone distribution, and whether enough VM instances exist to serve traffic.
Virtual Machines
intermediate
4 commands
Aliases: VMSS capacity, Virtual Machine Scale Set capacity, scale set instance count, sku.capacity, VMSS instance count
Quick peek
Open full term page
Containers
premium
Cluster autoscaler
The cluster autoscaler changes AKS node count based on pending pods and scheduling needs.
Kubernetes
fundamentals
3 commands
Aliases: No aliases yet
Quick peek
Open full term page
Containers
field-manual-complete
AKS cluster autoscaler
The AKS cluster autoscaler changes how many Kubernetes nodes are available in an Azure Kubernetes Service cluster. When pods are waiting because there is not enough room, it can add nodes to a node pool. When nodes sit underused, it can remove them safely after checks. It is not the same as scaling application replicas; it scales the infrastructure those replicas land on. Good settings keep workloads moving without leaving expensive virtual machines idle all week.
Azure Kubernetes Service
intermediate
5 commands
Aliases: cluster autoscaler, AKS node autoscaler, node pool autoscaler, CA on AKS
Quick peek
Open full term page
Containers
learning-path-anchor
System node pool
A system node pool is the AKS worker pool that keeps the cluster itself functioning. It hosts core Kubernetes and AKS add-on pods such as DNS, networking agents, metrics, and connectivity components. You can technically run application pods there, but experienced teams avoid that because noisy workloads can starve the services that make the...
Azure Kubernetes Service
intermediate
4 commands
Aliases: AKS system pool, system mode node pool, AKS platform node pool, kube-system node pool
Quick peek
Open full term page
Containers
premium
Azure Kubernetes Service
Azure Kubernetes Service is Azure’s managed Kubernetes service for deploying, scaling, and operating containerized applications while Azure manages much of the cluster control plane.
Managed Kubernetes
advanced
6 commands
Aliases: AKS, managed Kubernetes
Quick peek
Open full term page
No glossary terms matched that search.
Try a service name, acronym, command group, or category such as RBAC , az group , App Service , Application Insights , Databases , or Azure AI Search .
Clear filters and show matches
Reset search