SigNoz is an open-source APM. It helps developers monitor their applications & troubleshoot problems, an open-source alternative to DataDog, NewRelic, etc.

SigNoz Community

Did you mean to ask how much does each row/record typically take and want to estimate the volume size to provision?

If there is anyway to measure the volume size based on the number of spans that would be great!

It entirely depends on the avg number of attributes your spans have. Ingest some data and look at the table size <https://kb.altinity.com/altinity-kb-useful-queries/altinity-kb-database-size-table-column-size/>

When I configure cold storage, do you know if clickhouse will automatically move the data to cold storage when don’t have enough space but the retention period not reached?

No, that doesn’t happen by default. You need to set up `move_factor` in policy. Please read about `move_factor` ratio in ClickHouse storage policies.