> For the complete documentation index, see [llms.txt](https://motivlabs.gitbook.io/impulse-install-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://motivlabs.gitbook.io/impulse-install-manual/installation/astro/jaeger.md).

# Jaeger

Astro is able to connect to a remote Jaeger and has additional environment variables to control Jaeger options. 

## ENV Vars

### astro.conf

At the moment, the `astro.conf` file has only one option. 

* `JAEGER_DISABLED`
  * This controls whether Impulse should try to use Jaeger or not. By default this is set to `false` for testing purposes. 
  * Set to `true` to stop Impulse from connecting to Jaeger. This will help clean up additional logs when Jaeger is not running. 

### docker-compose.yml

The remaining Jaeger environment variables are in each docker-compose.yml file. i.e., `docker-tools/compose-template/impulse-core/docker-compose.yml` and `docker-tools/compose-template/strapi4-connector/docker-compose.yml`

As a result to connect to a remote Jaeger each individual container in appropriate docker-compose.yml must have it's ENV vars updated. 

* `JAEGER_AGENT_HOST`
  * The host to connect to Jaeger. Set this to connect to a remote Jaeger. i.e., `JAEGER_AGENT_HOST=jaeger or JAEGER_AGENT_HOST=10.0.1.60`
* `JAEGER_AGENT_PORT`
  * The port to connecto to Jaeger. Set this to connect to Jaeger. i.e.,`JAEGER_AGENT_PORT=6831`
* `JAEGER_SAMPLER_TYPE`
  * The sampler type: `remote`, `const`, `probabilistic`, `ratelimiting` (default `remote`). Astro automatically sets this to `const`
* `JAEGER_SAMPLER_PARAM`
  * The sampler parameter (number). Astro sets this to 1. 
* `JAEGER_REPORTER_MAX_QUEUE_SIZE`
  * The reporter's maximum queue size (default `100`). Astro sets this to 100000. 

Additional ENV vars can be found in the [README](https://github.com/jaegertracing/jaeger-client-go#environment-variables) for the Jaeger library we use. This doc will also add additional details to the above ENV vars. 

## Jaeger config

Astro's Jaeger instance is controlled by the docker compose file at `docker-tools/compose-template/jaeger/docker-compose.yml`. This controls the Jaeger config for start and how it connects to Cassandra and such. This also is where the Jaeger Cassandra schema is created by a docker container. 

For more information review the [Jaeger documentation](https://www.jaegertracing.io/docs/1.22/).