# Overview

```{questions}
- What is UPPMAX?
- What is SNIC/NAISS?
- What is a cluster?

```

```{objectives}
- We'll get an overview of UPPMAX and SNIC/NAISS and how a computer cluster works
```

```{instructor-note}
- Approx timing: 9:15-9:30
- Theory
```

**UPPMAX = UppMACS**
- [Uppsala Multidisciplinary Center for Advanced Computational Science](http://uppmax.uu.se)

## NAISS
- [**National Academic Infrastructure for Supercomputing in Sweden**](https://www.naiss.se/)
- Mission: to provide a quality high-performance computing environment nationally

- Starting 1 January 2023, the National Academic Infrastructure for Supercomputing in Sweden (NAISS) is the new organization for high-performance computing, storage, and date services for academic users in Sweden. 
  - Replaces SNIC — the Swedish National Infrastructure for Computing
  - Linköping university is the host organization for NAISS, but NAISS acts independently with a national perspective and responsibility.
- From the users perspective, there will initially only be minimal differences between the SNIC and NAISS regimes.
  - FAQ:s — <https://www.naiss.se/about/>
- Application rounds: <https://supr.naiss.se/round/>
- NAISS and Uppsala University fund UPPMAX — UU’s supercomputing center.


## UPPMAX missions
- Runs the clusters placed in Uppsala.
- More details in the afternoon about Organisational orienteering!

    
## UPPMAX systems

- Clusters
  - Rackham (general purpose)
    - Snowy (Long runs and GPU:s)
  - Bianca (sensitive data)
    - Miarka (NGI production)
      - genomic data from the sequencing machines are pre-processed before they are delivered to the researcher.
- Storage
  - On-load, directly connected to the clusters
  - Off-load, for large data not needed for computation analysis anymore
- Cloud
  - Dis (region EAST-1)

## High Performance Computing — HPC
### What is a cluster?

- A network of computers, each computer working as a **node**.

- From small scale RaspberryPi cluster... 
     
![RaspBerry](./img/IMG_5111.jpeg)

- To supercomputers like Rackham.

![Rackham](./img/uppmax-light2.jpg)

- Each node contains several processor cores and RAM and a local disk called scratch.

![Node](./img/node.png)

- The user logs in to **login nodes**  via Internet through ssh or ThinLinc.

  - Here the file management and lighter data analysis can be performed.

![RaspBerry](./img/nodes.png)

![RaspBerry](./img/Bild1.png)

- The **calculation nodes** have to be used for intense computing. 

## Overview of the UPPMAX systems

```{mermaid}
  graph TB

  Node1 -- interactive --> SubGraph2Flow
  Node1 -- sbatch --> SubGraph2Flow
  subgraph "Snowy"
  SubGraph2Flow(calculation nodes) 
        end

        thinlinc -- usr-sensXXX + 2FA + VPN ----> SubGraph1Flow
        terminal -- usr --> Node1
        terminal -- usr-sensXXX + 2FA + VPN ----> SubGraph1Flow
        Node1 -- usr-sensXXX + 2FA + no VPN ----> SubGraph1Flow
        
        subgraph "Bianca"
        SubGraph1Flow(Bianca login) -- usr+passwd --> private(private cluster)
        private -- interactive --> calcB(calculation nodes)
        private -- sbatch --> calcB
        end

        subgraph "Rackham"
        Node1[Login] -- interactive --> Node2[calculation nodes]
        Node1 -- sbatch --> Node2
        end
```


```{keypoints}
- NAISS makes available large-scale high-performance computing resources, storage capacity, and advanced user support, for Swedish research. 
- UPPMAX runs the local resources placed at Uppsala Universtiy
- A cluster consists of several inter-connected computers that can work individually or together.
```