compactor: add series: symbol table size exceeds X bytes: X about thanos HOT 3 OPEN

Is it possible to implement some kind of sharding in your cluster? Thanos supports sharding using re-labelling: https://thanos.io/tip/thanos/sharding.md/#relabelling With sharding, compactors can create sharded smaller blocks and you'll likely not run into this hard limit.

@harry671003 Thanks for the prompt response. I have checked this out but it is super unclear to me how i would apply this.

The metrics come from 26 clusters and are all tagged with a globally unique label per cluster. We have 3 large receivers and all clusters write to a single remote write endpoint.

So for example is it possible to run 2 compactor instances each responsible for half the clusters? Would they not drop all blocks as we have a single remote write for all clusters?

See: https://github.com/prometheus/prometheus/blob/main/tsdb/docs/format/index.md#symbol-table.

Do i understand this correctly that dropping labels (for example uid) will reduce the size of this table?

from thanos.

This is a hard limit in the symbol table size in Prometheus TSDB of 4GB.
See: https://github.com/prometheus/prometheus/blob/main/tsdb/docs/format/index.md#symbol-table. The length field in the symbol table cannot exceed 4 bytes which limits the size to 2^32 bytes.

Is it possible to implement some kind of sharding in your cluster? Thanos supports sharding using re-labelling: https://thanos.io/tip/thanos/sharding.md/#relabelling
With sharding, compactors can create sharded smaller blocks and you'll likely not run into this hard limit.

from thanos.

I have checked this out but it is super unclear to me how i would apply this.

I'll admit that I haven't used this myself. Full disclaimer, I work on Cortex, another project that shares some code with Thanos. Maybe you can reach out on the Thanos slack channel asking for help.

Do i understand this correctly that dropping labels (for example uid) will reduce the size of this table?

Yes. The symbol table contains all the unique label strings. Dropping high cardinality labels will reduce the size of the symbol table.

from thanos.