feat: normalize stream record sequence numbers to backend-specified w… - #353
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Backends that need per-node identity (e.g. to construct unique hybrid logical clock (HLC) values for stream sequence ids), can receive an identity via StorageConfig during extenddb serve. Default implementations to avoid breaking backends that don't need this.
jcshepherd
requested review from
LeeroyHannigan,
amrith,
c33howard,
pdf-amzn,
robinnsc and
yesyayen
as code owners
September 15, 2026 22:21
robinnsc
previously approved these changes
Sep 19, 2026
yesyayen
approved these changes
Sep 22, 2026
5 tasks
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What
Stream record sequence numbers are normalized (padded) to a fixed width specified by the backend, with default.
Why
Current backends use simple sequence numbers for stream records, and have default to a 21-char fixed width left-padded (with 0's) string. Cassandra doesn't support simple sequence numbers and uses a logical clock instead for stream seq numbers. It needs a slightly wider padded value (23 chars instead of 21). This enables the backend to specify the width it needs, and defaults to 21 chars for existing backends.
Closes #
Testing done
unit test for padding
cargo test --workspace
devtools/run-tests --extenddb --pytest (on PostgreSQL)
Checklist
cargo test --workspace)cargo fmt --check)cargo clippy -- -W clippy::pedantic)Storagetrait, auth model, on-diskformat, or public CLI surface, an RFC has been accepted or is linked
below. Otherwise, an ADR captures the decision (link below).
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Origin (DCO). See CONTRIBUTING.md for details.