# Introduction to Astor

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{audience}`all`
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## Goal

- The first goal is to know at a quick glance, if everything is OK in a
  control system,
  and otherwise to be able to diagnose a problem and solve it.
- The second goal is to configure the control system and its
  components.
- The third goal is to have long term analysis on components (logs,
  statistics, usage,....)

## Principle

- On each host to be controlled, a device server (called [Starter](https://tango-controls.readthedocs.io/en/latest/administration/deployment/starter.html))
  takes care of all device servers running (or supposed to) on this computer.

- The controlled server list is read from the TANGO database.

- A graphical client (called Astor) is connected to all Starter servers and is able to:

  - Display the control system status and component status using
    coloured icons.
  - Execute actions on components (start, stop, test, configure,
    display information, ....
  - Execute diagnostics on components.
  - Execute global analysis on a large number of crates or database.

![main windows](img/Astor-Starter.gif)

To control a host in remote, the TANGO device server Starter must be running on it.

:::{warning}
The starter device must have a specific name to be recognized by
astor. This name must be **tango/admin/\{hostname}** (e.g. *tango/admin/hal*).
:::

## Running Astor

- {program}`Astor` is a **Java** program using **Swing** classes.
  Classes has been compiled and the jar file has been built whith {program}`java-1.7`.
- To start the application, start the script file:
  {command}`$TANGO_HOME/bin/astor`
- **There are 3 modes to start Astor:**

 | Parameter   | Mode                                                                        |
 | ----------- | --------------------------------------------------------------------------- |
 | -rw or none | {program}`Astor` is fully **READ/WRITE**"                                   |
 | -db_ro      | {program}`Astor` is **READ/WRITE** but {program}`Database` is **READ_ONLY** |
 | -ro         | {program}`Astor` is fully **READ_ONLY**                                     |

## Display

- At startup, Astor display a tree where node could be a family of
  hosts (see Starter properties), and leaf are hosts where a Starter
  device server is registred in database.

- The icon of the leaf depends on the controlled device servers status
  as the following definition:

| For Hosts                                                                   |
| --------------------------------------------------------------------------- |
| ![green bal](img/greenball.png){.bg-transparent} All controlled servers are running.                            |
| ![blue bal](img/blueball.png){.bg-transparent} Starter is starting  server(s).                                |
| ![orange bal](img/orangeball.png){.bg-transparent} At least, one controlled server is stopped and one is running. |
| ![white bal](img/whiteball.png){.bg-transparent} All controlled servers are stopped.                            |
| ![red bal](img/redball.png){.bg-transparent} Starter is not running on host.                                |

| For Servers                                               |
| --------------------------------------------------------- |
| ![green bal](img/greenball.png){.bg-transparent} Server is running                            |
| ![blue bal](img/blueball.png){.bg-transparent} Server is running but not alive (Starting ?) |
| ![red bal](img/redball.png){.bg-transparent} Server is not running.                       |

## Host Control

![green bal](img/Astor.png){.bg-transparent}
<!--```{image} img/Astor.png
:class: bg-transparent
```-->

## Source

You can find the source code [here](https://gitlab.com/tango-controls/Astor)

## Distribution

You can download the project [here](https://central.sonatype.com/artifact/org.tango-controls/Astor/versions)