SQD Network combines multiple chunk copies with request retries. These mechanisms
reduce the effect of a single worker failure, but they do not guarantee that every
dataset is always available. Availability still depends on valid assignments,
reachable workers, complete chunk downloads, and the services around them.
What happens when a component changes
Replication only helps when another assigned worker has completed the chunk
download and can answer the query. A configured replication count is not proof
that every copy is currently reachable.
Worker status
The current worker exposes an HTTP service on its metrics port:
/worker/status reports how many assigned chunks are available or downloading.
/metrics exposes Prometheus metrics for storage, downloads, queries, assignment
state, and peer-to-peer activity.
The worker guide owns the setup, update, backup, and
troubleshooting procedures. This page only explains how the signals fit into the
Network.
Network observers and collectors
The observer joins the peer-to-peer network and exposes metrics including:
- when a peer was last seen;
- peer ping count and last ping duration;
- a worker’s reported storage use and missing chunk count;
- the assignment timestamp reported by the worker.
Separate collectors receive worker heartbeats and query logs over the Network
transport and store them in ClickHouse. Portal also exposes /ready and /metrics.
Its specification defines request, dependency, worker-selection, and assignment
signals, while its gap register identifies signals that are not implemented yet.
Implementation sources
Return to Network components or
continue with the operational worker guide. 