Query service is the interface between forntend and databases. It is written in Golang. It will have modules for all supported databases. Query service is responsible to:

parse the request from Frontend
create relevant Druid queries (and all other supported database queries)
parse response from databases and handle error if any
build response in the format accepted by Frontend

Druid Queries

Internally we use both native and sql queries to Druid.

Configuration

Query Service needs below env variables to run:

    DruidClientUrl: http://signoz-druid-router:8888
    DruidDatasource: flattened_spans

The above values are the default ones used by SigNoz and are kept at deploy/kubernetes/platform/signoz-charts/query-service/values.yaml

Build and Run locally

cd pkg/query-service
go build -o build/query-service main.go
DruidClientUrl=xxxx DruidDatasource=flattened_spans build/query-service

Docker Images

The docker images of query-service is available at https://hub.docker.com/r/signoz/query-service