Sessions¶
Connect to machines and containers launched by your formations.
Overview¶
When you launch a formation, RosettaHub creates a session -- your live connection to the infrastructure that the formation provisions. A session gives you access to one or more machines (cloud instances) or containers, depending on the formation type.
| Concept | Description |
|---|---|
| Formation | Recipe/template defining infrastructure |
| Session | Live connection to the launched infrastructure |
| Machine | Cloud instance (EC2, Azure VM, GCE, ECS, OVH instance, OpenStack instance) within a session |
| Container | Docker container running inside a managed image |
RosettaHub provides real-time cost tracking on every session, so you always know what you are spending.
Session Types¶
Different formation types produce different session structures:
| Type | Created By | Structure |
|---|---|---|
| Single-Machine | Machine, Docker formations | One cloud instance or container with direct SSH, RDP, or browser access |
| Multi-Machine | Pool, Virtual Lab, Cluster formations | Multiple machines managed independently within one session |
Multi-Machine Session Structures¶
| Formation Type | Session Structure |
|---|---|
| Machine Pool | Pool of identical machines for batch processing or workshops |
| Virtual Lab | Proxy machine (browser gateway) + target machine (your workstation) |
| EMR/Dataproc Cluster | Proxy + master node + worker nodes |
| HPC Cluster | Head node + compute nodes + shared storage |
Machine States¶
Machines within a session transition through these states:
| State | Description |
|---|---|
| Pending | Instance is being provisioned |
| Running | Instance is active and accessible |
| Stopped | Instance is stopped (storage preserved) |
| Hibernated | Instance state saved to disk |
| Terminated | Instance has been deleted |
Session Actions¶
Lifecycle Actions¶
Control the state of machines within your session:
| Action | Description |
|---|---|
| Start | Resume a stopped or hibernated machine |
| Stop | Stop the machine (preserves root volume) |
| Hibernate | Save machine state to disk for later resumption |
| Reboot | Restart the machine |
| Force Reboot | Hard restart without graceful shutdown |
| Shutdown | Graceful shutdown of the machine |
| Force Stop | Immediate stop without graceful shutdown |
| Force Hibernate | Immediate hibernate without graceful shutdown |
| Delete | Terminate the machine permanently |
Spot Instances
Spot/Preemptible instances may be terminated by the cloud provider with little notice. Use snapshot features to preserve your work.
Connection Actions¶
| Action | Description |
|---|---|
| Connect | Open connection options for the machine |
| Remote Desktop | Browser-based graphical desktop access |
| RDP | Windows Remote Desktop Protocol connection |
| Get RDP File | Download RDP connection file |
| Putty | Open SSH connection via PuTTY |
| SSH Connect | Terminal SSH connection |
Image Actions¶
Capture the state of a running machine or container as a reusable image:
| Action | Description |
|---|---|
| Snapshot | Create a machine image from current state |
| Snapshot Container | Create image of the Docker container (managed images) |
Managing Sessions¶
Starting and Stopping¶
To conserve costs when not actively using a session:
- Select the machine in the Machines panel
- Right-click and choose Stop
- The machine stops but retains its root volume
- To resume, select the stopped machine and choose Start
Cost Savings
Stopped instances don't incur compute charges, but you still pay for attached storage volumes.
Hibernating¶
Hibernation saves the machine's memory state to disk -- including for spot instances, where hibernation can preserve your work when the cloud provider reclaims capacity (saving 60-90% compared to on-demand pricing):
- Select a running machine
- Right-click and choose Hibernate
- The machine state is saved and the instance stops
- When started, the machine resumes exactly where it left off
Hibernation Requirements
- Root volume must have enough space for memory contents
- Instance type must support hibernation
- Not all operating systems support hibernation
Creating Images from Sessions¶
Capture customizations from a running session:
- Configure your machine as needed (install software, configure settings)
- Select the machine in the Machines panel
- Right-click and choose Snapshot or Snapshot Container
- Enter a name and description
- The new image appears in your Images panel
Before Snapshotting
- Clean up temporary files
- Remove sensitive data and credentials
- Stop unnecessary services
- Consider the root volume size
Session vs Formation¶
| Aspect | Formation | Session |
|---|---|---|
| Nature | Template/Recipe | Live connection to running infrastructure |
| State | Static definition | Dynamic (running/stopped/hibernated) |
| Actions | Clone, Customize, Update | Start, Stop, Connect, Delete |
| Cost | No cost | Incurs cloud charges |
| Persistence | Permanent | Temporary (until deleted) |
Best Practices¶
Resource Management
- Stop sessions when not in use
- Delete terminated sessions to clean up resources
- Use Spot instances for cost-sensitive workloads
- Set up auto-stop for idle machines
Data Persistence
- Important data should be stored on attached volumes, not the root volume
- Create snapshots before major changes
- Use object storage for long-term data persistence
Monitoring
- Check session status regularly -- RosettaHub shows real-time cost tracking per machine
- Monitor aggregate costs through Cloud Accounts
- Review running sessions at end of day
Related Topics¶
- MetaCloud Overview - The compute layer of the Supercloud
- Formations - Create cloud-agnostic IaC recipes
- Images - Machine images for launching
- Cloud Keys - Credentials for cloud access