Alibaba ACP Cloud Computing flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Region vs Zone

A region is a geographic area; zones are isolated datacenters within a region connected by low-latency links. Multi-zone deployment gives fault isolation without cross-region latency.

Shared responsibility model

Alibaba Cloud secures physical infrastructure, hypervisor, and managed-service platform; the customer secures guest OS, applications, data, and identity and access configuration.

VPC scope

A Virtual Private Cloud is region-scoped, while its vSwitches are zone-scoped. An HA design therefore places vSwitches in at least two zones of one region.

Resource group

A logical container for resources within an Alibaba Cloud account, used to group resources for authorization and cost allocation together with tags.

ECS instance families

General-purpose (g), compute-optimized (c), memory-optimized (r), plus storage, GPU, and burstable types. Selection is driven by CPU-to-memory ratio and workload profile.

Subscription vs Pay-As-You-Go

Subscription is prepaid for a fixed term at a lower unit price; Pay-As-You-Go bills per second or hour with no commitment. Spot instances suit fault-tolerant batch work.

ESSD disk levels

Enhanced SSD comes in PL0 through PL3 performance levels; IOPS and throughput increase with PL level and, for some levels, with disk capacity.

Security group behavior

A stateful, instance-level virtual firewall. Rules are allow-only, evaluated by priority, and configured separately for inbound and outbound directions.

Instance metadata service

An endpoint at 100.100.100.200 reachable from inside an ECS instance that returns instance ID, region, and temporary role credentials to running code.

EIP vs public IP

An EIP is a standalone, retainable public IP that can be unbound and rebound to other resources; an instance-assigned public IP is released with the instance.

NAT Gateway

A managed VPC gateway that lets private instances without public IPs initiate outbound internet traffic, typically via a 0.0.0.0/0 route entry.

SLB types

CLB is the classic layer 4/7 balancer; ALB targets HTTP/HTTPS/gRPC with advanced routing; NLB is a high-performance layer 4 balancer.

PrivateZone

A private DNS service that resolves internal domain names only within associated VPCs, enabling stable service names for internal architectures.

CEN

Cloud Enterprise Network interconnects many VPCs and on-premises networks through a central routing hub, avoiding a full mesh of VPC peerings.

OSS storage classes

Standard, Infrequent Access, Archive, Cold Archive, and Deep Cold Archive. Lower-cost classes trade retrieval time and impose minimum storage durations.

OSS ZRS vs LRS

Local Redundant Storage keeps copies within one zone; Zone-Redundant Storage spreads copies across zones in a region for higher durability against zone failure.

NAS

A managed shared file system using NFS or SMB that many ECS instances can mount simultaneously, suitable for shared content and lift-and-shift file workloads.

Hybrid Backup Recovery

A managed backup service that protects ECS disks and files, NAS, OSS, and on-premises data into backup vaults using scheduled policies and retention rules.

PolarDB architecture

A cloud-native database with compute-storage separation; up to 15 read-only nodes share one storage layer, enabling fast cloning and backups.

RDS read-only instance

A read-only replica created from an RDS primary that offloads read queries. Applications use read/write splitting to route reads to it.

RDS point-in-time recovery

Full and incremental backups plus log backups let you restore an RDS instance to a specific moment within the configured backup retention window.

Redis cluster edition

ApsaraDB for Redis cluster edition shards data across multiple nodes for horizontal scale, while standard edition uses a primary/standby pair for high availability.

RAM role

An identity assumed by trusted entities such as ECS instances or other accounts, granting temporary STS credentials instead of long-term AccessKeys.

RAM policy structure

A JSON document with Effect (Allow/Deny), Action, Resource, and Condition fields; attached to users, groups, or roles to grant scoped permissions.

WAF

Web Application Firewall inspects HTTP/HTTPS traffic in front of load balancers to block SQL injection, XSS, and other OWASP web attacks.

Anti-DDoS scrubbing

Attack traffic is diverted to a scrubbing center that filters malicious packets and forwards clean traffic to the origin, protecting public-facing IPs.

Auto Scaling components

A scaling group defines min/max/desired capacity and zone scope; a scaling configuration is the instance template; rules and alarms trigger scaling.

Scaling cooldown

A waiting period after a scaling activity completes during which further scaling actions are suppressed, preventing rapid repeated scale-out and scale-in.

Lifecycle hook

An Auto Scaling feature that pauses instance add or remove events so custom scripts can run before the instance joins or leaves the scaling group.

CloudMonitor alarms

Metric-based rules that evaluate thresholds over periods and trigger notifications or automated actions such as Auto Scaling when breached.

SLB 502/504 errors

These indicate backend health check failure, backend response timeout, or an application error. Verify backend health status, port, and timeout settings.

Savings plan

A commitment-based discount where a 1- or 3-year spend commitment lowers the unit price of eligible compute resources compared with pure Pay-As-You-Go.