Articles
80 articles
CloudWatch log groups that never expire: How to Find Them and What They Cost
Log groups default to Never Expire, so ingestion and storage charges accumulate indefinitely. What that costs, how to list them, and the retention fix.
Cross-AZ data transfer: How to Find Them and What They Cost
Cross-AZ traffic is charged per gigabyte in both directions, invisible on the bill until you know where to look. What it costs, and how to cut it.
gp2 volumes not migrated to gp3: How to Find Them and What They Cost
gp2 volumes cost about 20% more than gp3 for the same or worse performance. What the difference is worth, how to list yours, and how to migrate safely.
Idle load balancers: How to Find Them and What They Cost
Idle ALBs and NLBs bill hourly with no healthy targets and no requests. What they cost, the command that lists yours, and what to check before deleting.
Idle NAT gateways: How to Find Them and What They Cost
Idle NAT gateways bill by the hour for a path nothing uses. What they cost, the command that lists yours, and what to check before deleting one.
Idle RDS instances: How to Find Them and What They Cost
Idle RDS instances bill compute and storage around the clock with no connections. What they cost, how to list them, and what to check before stopping one.
Old EBS snapshots: How to Find Them and What They Cost
Old EBS snapshots accumulate forever, including ones behind deregistered AMIs. What they cost, the command that lists yours, and what to check first.
Orphaned network interfaces: How to Find Them and What They Cost
Orphaned network interfaces hold IP addresses and block security group and subnet deletion. What they cost, how to list them, and what to check first.
S3 incomplete multipart uploads: How to Find Them and What They Cost
S3 incomplete multipart uploads are billed as storage and invisible in the console and the bucket listing. What they cost, how to find them, and the fix.
S3 noncurrent versions with no lifecycle rule: How to Find Them and What They Cost
Versioning with no expiry policy keeps every previous version of every object forever. What that costs, how to measure it, and the lifecycle rule to add.
Unassociated Elastic IPs: How to Find Them and What They Cost
Unassociated Elastic IPs bill hourly and eat a quota of five per region. What they cost, the command that lists yours, and what to check before releasing.
Unattached EBS volumes: How to Find Them and What They Cost
Unattached EBS volumes bill at full price for storage nobody reads. What they cost, the CLI command that lists yours, and what to check before deleting.
EC2 MTU: 1500 vs 9001, and Why Jumbo Frames Break at the VPC Edge
EC2 instances default to a 9001-byte MTU inside the VPC and 1500 bytes to the internet. Where the boundary sits, and why transfers hang while pings succeed.
100.64.0.0/10 in AWS: Using CGNAT Space to Fix EKS IP Exhaustion
When an EKS cluster runs out of pod IPs and the VPC has no RFC 1918 space left, a 100.64.0.0/10 secondary CIDR is the fix. Why AWS allows it, and what breaks.
AWS `AccessDenied vs AccessDeniedException`: What It Means and How to Fix It
AccessDenied and AccessDeniedException are two IAM denial formats from two generations of AWS API. What each one tells you, and how to fix both.
AWS `AddressLimitExceeded`: What It Means and How to Fix It
AddressLimitExceeded is the Elastic IP quota — five per region by default, and usually full of addresses nothing is using. Causes, fixes and checks.
AWS `CannotPullContainerError`: What It Means and How to Fix It
CannotPullContainerError is an ECS task that cannot fetch its image — networking about half the time, IAM the other half. Ranked causes and fixes.
AWS `Client.InternalError`: What It Means and How to Fix It
Client.InternalError kills an EC2 instance right after launch, nearly always because of a KMS key it cannot use. The ranked causes and their fixes.
AWS `ExpiredToken`: What It Means and How to Fix It
ExpiredToken from AWS STS means your temporary credentials passed their expiry time. Why sessions end early, how to refresh, and how to prevent it.
AWS `failed to assign an IP address to container`: What It Means and How to Fix It
failed to assign an IP address to container is the VPC CNI out of addresses: a full subnet, or a node at its ENI limit. Ranked causes and fixes.
AWS `0/N nodes are available: Insufficient cpu`: What It Means and How to Fix It
0/N nodes are available: Insufficient cpu is the scheduler saying no node has room — measured against requests, not usage. Causes and their fixes.
AWS `InsufficientInstanceCapacity`: What It Means and How to Fix It
InsufficientInstanceCapacity is AWS running out of physical capacity in that availability zone — not a quota. What to change to get an instance now.
AWS `InvalidClientTokenId`: What It Means and How to Fix It
InvalidClientTokenId means AWS does not recognise the access key at all — deleted, deactivated, or from the wrong partition. Causes, fixes and checks.
AWS `Task timed out after N seconds`: What It Means and How to Fix It
Task timed out after N seconds is a Lambda killed at its configured timeout, often waiting on a call that can never complete. Causes and their fixes.
AWS `Lambda in a VPC cannot reach the internet`: What It Means and How to Fix It
Attaching a Lambda function to a VPC removes its internet access — the most predictable Lambda failure there is. Why it happens, and the two fixes.
AWS `FATAL: remaining connection slots are reserved`: What It Means and How to Fix It
FATAL: remaining connection slots are reserved is a PostgreSQL RDS instance at its connection ceiling — usually pooling, not load. Causes and fixes.
AWS `RequestTimeTooSkewed`: What It Means and How to Fix It
RequestTimeTooSkewed is a clock problem wearing the costume of a credentials problem. Why AWS rejects a skewed request, and how to fix the drift.
AWS `ResourceInitializationError`: What It Means and How to Fix It
ResourceInitializationError is a Fargate task that cannot reach Secrets Manager, SSM or ECR before it starts. Ranked causes, fixes, and the checks.
AWS `Runtime.ImportModuleError`: What It Means and How to Fix It
Runtime.ImportModuleError is the Lambda runtime failing to load your handler — a packaging or path problem, not a code bug. Causes and their fixes.
AWS `SignatureDoesNotMatch`: What It Means and How to Fix It
SignatureDoesNotMatch is the SigV4 signature failing to verify — almost always a malformed secret key, not a wrong one. Ranked causes and fixes.
AWS `SlowDown`: What It Means and How to Fix It
SlowDown from S3 is throttling on a single prefix — a partitioning problem, not a bucket-wide limit. Ranked causes, fixes, and how to spread the load.
AWS `ThrottlingException / RequestLimitExceeded`: What It Means and How to Fix It
ThrottlingException and RequestLimitExceeded are the AWS API rate limiter, usually reacting to code that polls in a loop. Causes, fixes and backoff.
AWS `UnauthorizedOperation`: What It Means and How to Fix It
UnauthorizedOperation from the EC2 API means IAM evaluated your request and said no. The ranked causes, a fix for each, and how to prove which one.
AWS `VcpuLimitExceeded`: What It Means and How to Fix It
VcpuLimitExceeded is an EC2 account quota, not a capacity shortage — and this one you can raise. How to read the limit, and how to request more.
Why AWS Reserves 5 IP Addresses in Every Subnet (and What Each One Does)
AWS takes five addresses out of every VPC subnet: network, router, DNS resolver, one in reserve, and broadcast. What each is for, and how it changes sizing.
Ephemeral Ports and the Network ACL Rule Everyone Forgets
Security groups are stateful, network ACLs are not. A NACL allowing inbound 443 but not outbound 1024-65535 lets a connection start, then kills it.
NAT Gateway vs NAT Instance vs VPC Endpoint: Which One, and What It Costs
Three ways to give private subnets outbound access, with very different bills. Where each one wins, and why an S3 gateway endpoint is the cheapest fix.
The VPC DNS Limit: 1,024 Packets per Second per ENI
The VPC resolver caps every network interface at 1,024 DNS packets per second. It is not adjustable, has no CloudWatch metric, and looks like random SERVFAIL.
5 Critical Mistakes to Avoid with AWS Lambda Durable Functions
Avoid five critical AWS Lambda Durable Functions mistakes, from non-deterministic code and missing IAM permissions to unqualified ARNs and SDK drift.
AWS Lambda Durable Functions
AWS Lambda Durable Functions use a checkpoint-and-replay model to build stateful, multi-step workflows that suspend up to a year with no idle compute cost.
AWS Lambda Durable Functions vs Step Functions
See how AWS Lambda Durable Functions replace Step Functions by building a stateful order-processing workflow in code with steps, checkpoints, and waits.
What are Amazon EKS Capabilities
Explore Amazon EKS capabilities including managed control plane, EKS Auto Mode, off-cluster platform services like Argo CD and ACK, and VPC CNI networking.
AWS Lambda Managed Instances Explained
AWS Lambda Managed Instances run functions on EC2-backed capacity providers, unlocking GPUs, Graviton, Savings Plans, and a parallel runtime worker model.
Deploying Your First VPC-Backed Lambda Managed Instance
Deploy your first VPC-backed Lambda Managed Instance with a guide to dual IAM roles, networking, capacity providers, and mandatory version publishing.
How Runtime Workers Change the AWS Lambda Behavioral Model
AWS Lambda runtime workers process multiple events per instance, demanding thread-safe code and unlocking a 15-minute init phase in Lambda Managed Instances.
Leveraging GPUs and Graviton with Lambda Managed Instances
AWS Lambda Managed Instances bring GPUs, Graviton4, and EFA networking to serverless, powering AI inference and HPC workloads without managing EC2 clusters.
Monitoring and Troubleshooting Lambda Managed Instances
Monitor and troubleshoot AWS Lambda Managed Instances by handling backpressure, unhealthy execution environments, and VPC telemetry paths for logs and traces.
When to use AWS Lambda Managed Instances
AWS Lambda Managed Instances lets you apply EC2 Savings Plans to serverless compute, but its 15% management fee pays off for steady, predictable workloads.
5 EKS Networking Tweaks That Cut Your AWS Bill by 40%
Cut Amazon EKS network costs up to 40 percent with five tweaks covering cross-AZ traffic, IP-mode load balancers, VPC endpoints, and NAT gateway placement.
EKS Cost Visibility: Kubecost vs AWS Native Tools vs OpenCost
Compare Kubecost, OpenCost, AWS Cost Explorer, and EKS split cost allocation for pod- and namespace-level cost visibility, and pick the right approach.
EKS vs ECS vs Fargate: Total Cost of Ownership Breakdown
Compare EKS, ECS, and Fargate on true total cost of ownership, factoring in compute, control plane fees, labor, and training across small to enterprise teams.
Karpenter vs Cluster Autoscaler: The Complete Decision Matrix
Compare Karpenter and Cluster Autoscaler for EKS node scaling across speed, bin-packing, Spot handling, and cost, with a decision matrix and migration guide.
Savings Plans vs Reserved Instances for Dynamic EKS Workloads
Learn why Compute Savings Plans beat Reserved Instances for dynamic EKS workloads, how to size baseline commitments, and layer Spot to cut costs 60-70%.
Spot Instances on EKS: A Safety-First Implementation Guide
Run Spot instances on EKS safely using mixed capacity node groups, termination handlers, node affinity, and PodDisruptionBudgets to cut compute costs 60-90%.
The EKS Cost Optimization Checklist
Follow a 30/60/90-day EKS cost optimization plan covering cost visibility, right-sizing, autoscaling, and Spot adoption to reduce cluster spend by 50-80%.
The Hidden EKS Costs: Storage, Networking, and Orphaned Resources
Cut hidden EKS costs by finding orphaned EBS volumes and load balancers, migrating to gp3, adding VPC endpoints, and reducing cross-AZ data transfer charges.
AWS WAF for CloudFront: Edge Protection Overview
Attaching AWS WAF to CloudFront filters SQL injection, XSS, bots, and abusive traffic at 450+ edge locations, cutting origin load and bandwidth costs.
AWS WAF Use Cases & Scenarios
AWS WAF handles key use cases from blocking OWASP exploits and credential stuffing to protecting on-premises origins and centralizing multi-account policies.
AWS WAF vs Marketplace WAF Solutions
Compare AWS WAF with Marketplace alternatives like Barracuda, Fortinet, and Imperva to decide when native managed rules suffice or vendor ML detection fits.
When to Use AWS WAF vs AWS Shield vs Network Firewall
AWS WAF, Shield, and Network Firewall protect different layers—WAF at layer 7, Shield against DDoS, Network Firewall for VPC traffic—as defense in depth.
Amazon AWS Web Application Firewall (WAF)
AWS WAF is a managed firewall that inspects HTTP(S) requests to block SQL injection, XSS, and bots at CloudFront, ALB, or API Gateway with AWS-managed rules.
Introduction to Amazon AWS Bedrock
Amazon Bedrock gives you API access to foundation models from Anthropic, Meta, and others. Learn pricing, RAG vs fine-tuning, security, and when to use it.
AWS Nitro Enclaves
AWS Nitro Enclaves isolate sensitive data inside EC2 with hardware-enforced isolation, KMS attestation, and vsock. Learn use cases, limits, and pricing.
Amazon AWS EBS vs EFS vs S3
Compare AWS EBS, EFS, and S3 storage: block volumes for single instances, shared NFS file storage, and scalable object storage to pick the right one.
Difference between AWS EC2 Reserved and Spot Instances
Compare AWS EC2 Reserved and Spot Instances to see how Reserved commitments cut costs up to 72% and Spot saves 90% on interruptible, fault-tolerant workloads.
Amazon AWS S3 Lifecycle Policies
AWS S3 lifecycle policies automatically transition objects to cheaper storage classes like Glacier and delete stale data, cutting storage costs by 50-70%.
Introduction to Amazon Elastic Block Store (EBS)
Amazon EBS provides persistent, high-performance block storage for EC2. Learn volume types, snapshots, availability zone rules, durability, and pricing.
How to reduce Cloudwatch Costs
Cut CloudWatch costs by trimming log volume, shortening retention, replacing metric filters, consolidating alarms, and offloading bulky logs to S3.
Lambda vs Containers vs EC2
Compare AWS Lambda, containers, and EC2 to choose the right compute model based on runtime limits, control, scaling, and cost for your workload pattern.
AWS EC2 vs Fargate for ECS
Compare AWS Fargate and EC2 launch types for ECS: serverless simplicity vs full control, cost trade-offs, scaling, GPU support, and when to use each.
AWS Secrets Manager vs Parameter Store
Compare AWS Secrets Manager and Parameter Store on pricing, automatic rotation, encryption, throughput limits, and integrations to choose the right one.
Introduction to Amazon AWS EC2
Get started with Amazon EC2, the core AWS compute service, and learn how AMIs, instance types, EBS, security groups, and key pairs launch a server.
Amazon AWS Security Groups Explained
Understand AWS security groups, the stateful instance-level firewall for EC2. Learn default allow-only rules and how referencing other groups secures app tiers.
Introduction to Amazon AWS Fargate
Learn how AWS Fargate runs containers serverlessly on ECS and EKS. Define CPU and memory while Fargate handles provisioning, scaling, and task isolation.
Introduction to Amazon ECS (Elastic Container Service)
Learn how Amazon ECS orchestrates Docker containers on AWS using EC2 or Fargate launch types, task definitions, services, and clusters for managed containers.
Introduction to Amazon AWS EFS
Learn how Amazon EFS delivers fully managed, elastic NFS file storage that many EC2 instances share across Availability Zones via mount targets.
Amazon AWS ECS vs EKS
Compare Amazon ECS vs EKS on architecture, setup, scaling, networking, and cost to decide between AWS-native simplicity and portable, standard Kubernetes.
Introduction to Amazon AWS EKS
Learn how Amazon EKS runs managed Kubernetes on AWS, from control plane and worker node options to VPC networking, IAM authentication, and monitoring.
Introduction to Amazon AWS
Get started with Amazon AWS by learning cloud computing fundamentals, Regions and Availability Zones, core services like EC2, VPC, S3, and IAM.
Introduction to Amazon AWS Lambda
Learn how AWS Lambda runs event-driven code without managing servers, covering triggers, runtimes, handlers, IAM roles, and pay-per-use millisecond billing.