Limitations and Differences

While Convox Cloud provides the same application deployment capabilities as self-hosted Convox Racks, there are some limitations due to its managed, multi-tenant nature. This guide outlines these limitations and provides alternatives where applicable.

Infrastructure Access Limitations

No Direct Kubernetes Access

Limitation: You cannot use kubectl to directly interact with the underlying Kubernetes cluster.

Impact:

Cannot apply custom Kubernetes manifests
Cannot install cluster-level operators or CRDs
Cannot modify cluster configurations

Alternatives:

Use convox.yml for all application configuration
Request features through Convox support for platform-wide needs
Consider self-hosted Rack if Kubernetes access is critical

No SSH Access to Nodes

Limitation: Cannot SSH into the underlying EC2 instances or container nodes.

Impact:

Cannot perform system-level debugging
Cannot install system packages directly
Cannot modify OS configurations

Alternatives:

Use convox cloud exec for container access
Include debugging tools in your Docker images
Use comprehensive logging and monitoring

Limited Shell Access

Limitation: Shell access is restricted to your application containers only.

Available Commands:

# Access running container
$ convox cloud exec my-service bash -a myapp -i my-machine

# Run one-off command
$ convox cloud run web "rails console" -a myapp -i my-machine

Configuration Limitations

Restricted Rack Parameters

Unlike self-hosted Racks, Cloud machines have limited configuration options:

Not Available:

Node instance types (fixed to machine size)
Network CIDR configuration
Custom security groups
VPC settings
Autoscaling policies for nodes
Custom IAM roles

Available:

Machine size (X-Small, Small, Medium, Large)
Region selection
Application-level configurations via convox.yml

Fixed Resource Ratios

Limitation: CPU to memory ratios are fixed per machine tier.

Machine	vCPU:RAM Ratio
X-Small	1:2 GB
Small	1:2 GB
Medium	1:2 GB
Large	1:2 GB

Impact: Cannot customize for memory-heavy or CPU-heavy workloads independently.

Alternatives: Choose the machine size that best fits your primary constraint.

Networking Limitations

No Custom Load Balancers

Limitation: Cannot configure custom load balancer types or settings.

Not Available:

Network Load Balancers (NLB)
Custom ALB configurations
Static IPs
Custom SSL policies

Available:

Standard HTTPS load balancing
Automatic SSL via Let's Encrypt
Custom domains
Path-based routing via convox.yml

Limited Network Policies

Limitation: Cannot define custom network policies or firewall rules.

Impact:

Cannot restrict inter-service communication
Cannot create network segments
Limited to application-level security

Alternatives:

Implement application-level authentication
Use service mesh patterns in your application
Leverage environment-based configuration

No VPC Peering

Limitation: Cannot establish VPC peering or private connectivity to your own AWS resources.

Impact:

Cannot directly connect to private RDS databases in your own AWS account
Cannot access private S3 endpoints
Cannot integrate with existing VPCs

Alternatives:

Use Cloud Databases (managed RDS through Convox)
Use public endpoints with security groups
Implement API-based integration

Database Resources

Cloud Databases (Managed RDS)

Convox Cloud provides fully managed RDS databases through Cloud Databases:

Available Database Types:

PostgreSQL (versions 14.x - 18.x)
MySQL (versions 8.0.x and 8.4.x)
MariaDB (versions 10.6.x - 11.8.x)

Configuration Example:

resources:
  database:
    type: postgres
    provider: aws
    options:
      class: small
      version: 17.5
      durable: true

services:
  web:
    resources:
      - database

Available Options:

Database class (dev, small, medium, large)
Database version
Multi-AZ failover (durable: true)

Not Available:

Custom RDS instance types
Custom storage sizes beyond class limits
Read replicas
Custom parameter groups

Containerized Databases

You can also use containerized databases (without provider: aws):

resources:
  database:
    type: postgres
    options:
      version: 13
      storage: 10

Note: Containerized databases do not persist data across machine restarts. Use Cloud Databases for production workloads.

External Databases

Not Available Through Cloud:

AWS ElastiCache
DocumentDB
DynamoDB

Alternatives:

Use resource overlays to connect to external databases
Provision managed databases separately and connect via environment variables

Storage Limitations

No Persistent Volumes

Limitation: No persistent volume support or EFS mounting.

Impact:

Data not persisted across deployments
Cannot share files between services
Limited to ephemeral container storage

Alternatives:

Use external object storage (S3)
Store data in Cloud Databases
Implement stateless architectures

No Custom Volume Mounts

Limitation: Cannot mount custom volumes or host paths.

Not Supported:

# This won't work in Cloud
volumes:
  - /host/path:/container/path

Supported:

Container's ephemeral storage
Volume sharing within a single service's containers

Build Limitations

Build Environment Restrictions

Fixed Build Resources:

Build CPU: Shared pool (not configurable)
Build Memory: 4 GB (not configurable)
Build Timeout: 30 minutes (not configurable)
Build Disk: 20 GB (not configurable)

Impact:

Large builds may fail due to memory limits
Cannot customize build performance
Long builds may timeout

Alternatives:

Optimize Dockerfiles for smaller builds
Use multi-stage builds
Pre-build base images

No Custom Build Nodes

Limitation: Cannot provision dedicated or custom build infrastructure.

Alternatives:

Use efficient build practices
Leverage Docker layer caching
Minimize build context size

Security Limitations

No Custom IAM Roles

Limitation: Cannot attach custom IAM roles to services.

Impact:

Cannot directly access AWS services with IAM authentication
Must use API keys for AWS service access

Alternatives:

Use environment variables for credentials
Implement service-to-service authentication
Use temporary credentials with STS

Limited Security Scanning

Limitation: No built-in container vulnerability scanning.

Alternatives:

Scan images in your CI/CD pipeline
Use external scanning services
Regularly update base images

Service Limitations

No Custom Services

Limitation: Cannot deploy system-level services or operators.

Not Supported:

Kubernetes operators
Admission webhooks
Custom controllers
Cluster-wide services
DaemonSets

Supported:

Standard application services via convox.yml
Sidecar containers within your services
Init containers

Agent Services Not Supported

Limitation: Cannot deploy agent-type services that run on every node.

Impact:

Cannot deploy custom monitoring agents
Cannot run node-level services
Cannot install custom log collectors

Alternatives:

Use built-in monitoring and logging
Include agents in your application containers
Use external SaaS monitoring solutions

Scaling Limitations

Machine-Level Constraints

Limitation: Services cannot scale beyond machine boundaries.

Maximum Resources per Machine:

Machine	Max Total CPU	Max Total RAM
X-Small	500m	1 GB
Small	1000m	2 GB
Medium	2000m	4 GB
Large	4000m	8 GB

Impact:

Single service cannot exceed machine resources
All services combined cannot exceed machine limits

Alternatives:

Upgrade to larger machine size
Distribute services across multiple machines
Optimize resource usage

No Cross-Machine Scaling

Limitation: A single application cannot automatically scale across multiple machines.

Alternatives:

Deploy to larger machines
Split into microservices on separate machines
Implement application-level sharding

Monitoring and Debugging Limitations

Basic Monitoring Only

Available Metrics:

CPU usage (basic)
Memory usage (basic)
Request counts
Error rates (HTTP)

Not Available:

Custom metrics
APM integration
Distributed tracing
Custom dashboards

Alternatives:

Export metrics from your application
Use external monitoring services
Implement application-level monitoring

Limited Log Retention

Limitation: Logs retained for 7 days only.

Alternatives:

Stream logs to external service
Implement application-level log shipping
Use external log aggregation

Compliance and Certification

Compliance Limitations

Not Available:

HIPAA compliance options
PCI DSS certification
SOC 2 attestation
ISO certifications
FedRAMP authorization

Available:

Standard security practices
Encrypted data in transit
Regular security updates

Alternatives:

Self-hosted Rack for compliance needs
Implement application-level compliance measures
Contact sales for enterprise options

Workarounds and Best Practices

Adapting to Limitations

Design for Statelessness
- Store state in Cloud Databases
- Use databases for persistence
- Implement session storage in Redis

Optimize Resource Usage

services:
  web:
    scale:
      cpu: 250
      memory: 512

Use Cloud Databases for Production

resources:
  database:
    type: postgres
    provider: aws
    options:
      class: small
      version: 17.5
      durable: true

Implement at Application Level
- Security: Application-level authentication
- Networking: Service mesh patterns
- Monitoring: APM libraries

When to Consider Self-Hosted Rack

Consider a self-hosted Convox Rack if you need:

Direct Kubernetes access
Custom infrastructure configuration
Compliance certifications
Private networking/VPC peering
Custom IAM roles
Persistent storage
System-level customization
Dedicated resources
Advanced RDS features (read replicas, custom instance types)

Feature Comparison Table

Feature	Convox Cloud	Self-Hosted Rack
Kubernetes Access	✗	✓
SSH to Nodes	✗	✓
Custom Node Types	✗	✓
VPC Configuration	✗	✓
Network Policies	✗	✓
Persistent Volumes	✗	✓
Custom IAM Roles	✗	✓
Managed Databases	✓ (Cloud DBs)	✓ (RDS Resources)
RDS Read Replicas	✗	✓
Agent Services	✗	✓
Custom Build Nodes	✗	✓
Rack Parameters	Limited	Full
Setup Time	Instant	10-20 min
Maintenance	None	Required
Pricing	Per Machine/DB	Infrastructure

Getting Help

If you're unsure whether Convox Cloud meets your requirements:

Review your application architecture against these limitations
Contact support@convox.com with specific requirements
Try the X-Small tier to test compatibility
Consider self-hosted Rack for full control

Next Steps

CLI Reference - Learn available commands
Cloud Databases - Database configuration options
Migration Guide - Move from other platforms
Comparison - Detailed Cloud vs Rack comparison

Limitations and Differences

Infrastructure Access Limitations

No Direct Kubernetes Access

Limitation: You cannot use kubectl to directly interact with the underlying Kubernetes cluster.

Impact:

Cannot apply custom Kubernetes manifests
Cannot install cluster-level operators or CRDs
Cannot modify cluster configurations

Alternatives:

Use convox.yml for all application configuration
Request features through Convox support for platform-wide needs
Consider self-hosted Rack if Kubernetes access is critical

No SSH Access to Nodes

Limitation: Cannot SSH into the underlying EC2 instances or container nodes.

Impact:

Cannot perform system-level debugging
Cannot install system packages directly
Cannot modify OS configurations

Alternatives:

Use convox cloud exec for container access
Include debugging tools in your Docker images
Use comprehensive logging and monitoring

Limited Shell Access

Limitation: Shell access is restricted to your application containers only.

Available Commands:

# Access running container
$ convox cloud exec my-service bash -a myapp -i my-machine

# Run one-off command
$ convox cloud run web "rails console" -a myapp -i my-machine

Configuration Limitations

Restricted Rack Parameters

Unlike self-hosted Racks, Cloud machines have limited configuration options:

Not Available:

Node instance types (fixed to machine size)
Network CIDR configuration
Custom security groups
VPC settings
Autoscaling policies for nodes
Custom IAM roles

Available:

Machine size (X-Small, Small, Medium, Large)
Region selection
Application-level configurations via convox.yml

Fixed Resource Ratios

Limitation: CPU to memory ratios are fixed per machine tier.

Machine	vCPU:RAM Ratio
X-Small	1:2 GB
Small	1:2 GB
Medium	1:2 GB
Large	1:2 GB

Impact: Cannot customize for memory-heavy or CPU-heavy workloads independently.

Alternatives: Choose the machine size that best fits your primary constraint.

Networking Limitations

No Custom Load Balancers

Limitation: Cannot configure custom load balancer types or settings.

Not Available:

Network Load Balancers (NLB)
Custom ALB configurations
Static IPs
Custom SSL policies

Available:

Standard HTTPS load balancing
Automatic SSL via Let's Encrypt
Custom domains
Path-based routing via convox.yml

Limited Network Policies

Limitation: Cannot define custom network policies or firewall rules.

Impact:

Cannot restrict inter-service communication
Cannot create network segments
Limited to application-level security

Alternatives:

Implement application-level authentication
Use service mesh patterns in your application
Leverage environment-based configuration

No VPC Peering

Limitation: Cannot establish VPC peering or private connectivity to your own AWS resources.

Impact:

Cannot directly connect to private RDS databases in your own AWS account
Cannot access private S3 endpoints
Cannot integrate with existing VPCs

Alternatives:

Use Cloud Databases (managed RDS through Convox)
Use public endpoints with security groups
Implement API-based integration

Database Resources

Cloud Databases (Managed RDS)

Convox Cloud provides fully managed RDS databases through Cloud Databases:

Available Database Types:

PostgreSQL (versions 14.x - 18.x)
MySQL (versions 8.0.x and 8.4.x)
MariaDB (versions 10.6.x - 11.8.x)

Configuration Example:

resources:
  database:
    type: postgres
    provider: aws
    options:
      class: small
      version: 17.5
      durable: true

services:
  web:
    resources:
      - database

Available Options:

Database class (dev, small, medium, large)
Database version
Multi-AZ failover (durable: true)

Not Available:

Custom RDS instance types
Custom storage sizes beyond class limits
Read replicas
Custom parameter groups

Containerized Databases

You can also use containerized databases (without provider: aws):

resources:
  database:
    type: postgres
    options:
      version: 13
      storage: 10

Note: Containerized databases do not persist data across machine restarts. Use Cloud Databases for production workloads.

External Databases

Not Available Through Cloud:

AWS ElastiCache
DocumentDB
DynamoDB

Alternatives:

Use resource overlays to connect to external databases
Provision managed databases separately and connect via environment variables

Storage Limitations

No Persistent Volumes

Limitation: No persistent volume support or EFS mounting.

Impact:

Data not persisted across deployments
Cannot share files between services
Limited to ephemeral container storage

Alternatives:

Use external object storage (S3)
Store data in Cloud Databases
Implement stateless architectures

No Custom Volume Mounts

Limitation: Cannot mount custom volumes or host paths.

Not Supported:

# This won't work in Cloud
volumes:
  - /host/path:/container/path

Supported:

Container's ephemeral storage
Volume sharing within a single service's containers

Build Limitations

Build Environment Restrictions

Fixed Build Resources:

Build CPU: Shared pool (not configurable)
Build Memory: 4 GB (not configurable)
Build Timeout: 30 minutes (not configurable)
Build Disk: 20 GB (not configurable)

Impact:

Large builds may fail due to memory limits
Cannot customize build performance
Long builds may timeout

Alternatives:

Optimize Dockerfiles for smaller builds
Use multi-stage builds
Pre-build base images

No Custom Build Nodes

Limitation: Cannot provision dedicated or custom build infrastructure.

Alternatives:

Use efficient build practices
Leverage Docker layer caching
Minimize build context size

Security Limitations

No Custom IAM Roles

Limitation: Cannot attach custom IAM roles to services.

Impact:

Cannot directly access AWS services with IAM authentication
Must use API keys for AWS service access

Alternatives:

Use environment variables for credentials
Implement service-to-service authentication
Use temporary credentials with STS

Limited Security Scanning

Limitation: No built-in container vulnerability scanning.

Alternatives:

Scan images in your CI/CD pipeline
Use external scanning services
Regularly update base images

Service Limitations

No Custom Services

Limitation: Cannot deploy system-level services or operators.

Not Supported:

Kubernetes operators
Admission webhooks
Custom controllers
Cluster-wide services
DaemonSets

Supported:

Standard application services via convox.yml
Sidecar containers within your services
Init containers

Agent Services Not Supported

Limitation: Cannot deploy agent-type services that run on every node.

Impact:

Cannot deploy custom monitoring agents
Cannot run node-level services
Cannot install custom log collectors

Alternatives:

Use built-in monitoring and logging
Include agents in your application containers
Use external SaaS monitoring solutions

Scaling Limitations

Machine-Level Constraints

Limitation: Services cannot scale beyond machine boundaries.

Maximum Resources per Machine:

Machine	Max Total CPU	Max Total RAM
X-Small	500m	1 GB
Small	1000m	2 GB
Medium	2000m	4 GB
Large	4000m	8 GB

Impact:

Single service cannot exceed machine resources
All services combined cannot exceed machine limits

Alternatives:

Upgrade to larger machine size
Distribute services across multiple machines
Optimize resource usage

No Cross-Machine Scaling

Limitation: A single application cannot automatically scale across multiple machines.

Alternatives:

Deploy to larger machines
Split into microservices on separate machines
Implement application-level sharding

Monitoring and Debugging Limitations

Basic Monitoring Only

Available Metrics:

CPU usage (basic)
Memory usage (basic)
Request counts
Error rates (HTTP)

Not Available:

Custom metrics
APM integration
Distributed tracing
Custom dashboards

Alternatives:

Export metrics from your application
Use external monitoring services
Implement application-level monitoring

Limited Log Retention

Limitation: Logs retained for 7 days only.

Alternatives:

Stream logs to external service
Implement application-level log shipping
Use external log aggregation

Compliance and Certification

Compliance Limitations

Not Available:

HIPAA compliance options
PCI DSS certification
SOC 2 attestation
ISO certifications
FedRAMP authorization

Available:

Standard security practices
Encrypted data in transit
Regular security updates

Alternatives:

Self-hosted Rack for compliance needs
Implement application-level compliance measures
Contact sales for enterprise options

Workarounds and Best Practices

Adapting to Limitations

Design for Statelessness
- Store state in Cloud Databases
- Use databases for persistence
- Implement session storage in Redis

Optimize Resource Usage

services:
  web:
    scale:
      cpu: 250
      memory: 512

Use Cloud Databases for Production

resources:
  database:
    type: postgres
    provider: aws
    options:
      class: small
      version: 17.5
      durable: true

Implement at Application Level
- Security: Application-level authentication
- Networking: Service mesh patterns
- Monitoring: APM libraries

When to Consider Self-Hosted Rack

Consider a self-hosted Convox Rack if you need:

Direct Kubernetes access
Custom infrastructure configuration
Compliance certifications
Private networking/VPC peering
Custom IAM roles
Persistent storage
System-level customization
Dedicated resources
Advanced RDS features (read replicas, custom instance types)

Feature Comparison Table

Feature	Convox Cloud	Self-Hosted Rack
Kubernetes Access	✗	✓
SSH to Nodes	✗	✓
Custom Node Types	✗	✓
VPC Configuration	✗	✓
Network Policies	✗	✓
Persistent Volumes	✗	✓
Custom IAM Roles	✗	✓
Managed Databases	✓ (Cloud DBs)	✓ (RDS Resources)
RDS Read Replicas	✗	✓
Agent Services	✗	✓
Custom Build Nodes	✗	✓
Rack Parameters	Limited	Full
Setup Time	Instant	10-20 min
Maintenance	None	Required
Pricing	Per Machine/DB	Infrastructure

Getting Help

If you're unsure whether Convox Cloud meets your requirements:

Review your application architecture against these limitations
Contact support@convox.com with specific requirements
Try the X-Small tier to test compatibility
Consider self-hosted Rack for full control

Next Steps

CLI Reference - Learn available commands
Cloud Databases - Database configuration options
Migration Guide - Move from other platforms
Comparison - Detailed Cloud vs Rack comparison

Find

Home Product Pricing Enterprise Blog Documentation

LinkedIn X GitHub

Chat

sales@convox.com