Fix LSM snapshot restoration by resolving double path nesting#2111
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Fix LSM snapshot restoration by resolving double path nesting#2111
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The LSM session was being initialised with the full lsmPath as both the
HasBlockIO root and the session's FsPath inside it, producing a doubled
on-disk layout like:
<state-dir>/lsm/<state-dir>/lsm/{active,snapshots,...}
instead of:
<state-dir>/lsm/{active,snapshots,...}.
Effect on snapshots: scripts/postgresql-setup.sh --create-snapshot looks
for the LSM tree at <state-dir>/lsm/snapshots/<slot>, didn't find it
because of the doubled path, silently fell back to the InMemory branch,
and produced a tarball missing the LSM tree files. On --restore-snapshot
+ db-sync startup the snapshot couldn't be loaded (ErrSnapshotDoesNotExist)
and sync replayed from genesis.
Fix:
Pass mkFsPath [] as the session's FsPath so it's rooted at the
HasBlockIO root directly. Also harden the snapshot script to abort with
a clear error when an lsm/ subtree exists but no LSM snapshot is found
at the expected path, instead of producing an incomplete tarball.
Files staged for commit:
- cardano-db-sync/src/Cardano/DbSync/Ledger/State.hs
- scripts/postgresql-setup.sh
kderme
approved these changes
Apr 28, 2026
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The LSM session was being initialised with the full lsmPath as both the HasBlockIO root and the session's FsPath inside it, producing a doubled on-disk layout like:
/lsm//lsm/{active,snapshots,...} instead of:
/lsm/{active,snapshots,...}.
Effect on snapshots: scripts/postgresql-setup.sh --create-snapshot looks for the LSM tree at /lsm/snapshots/, didn't find it because of the doubled path, silently fell back to the InMemory branch, and produced a tarball missing the LSM tree files. On --restore-snapshot
Fix:
Pass mkFsPath [] as the session's FsPath so it's rooted at the HasBlockIO root directly. Also harden the snapshot script to abort with a clear error when an lsm/ subtree exists but no LSM snapshot is found at the expected path, instead of producing an incomplete tarball.
Files staged for commit:
Description
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Checklist
fourmoluon version 0.17.0.0 (which can be run withscripts/fourmolize.sh)Migrations
If there is a breaking change, especially a big one, please add a justification here. Please elaborate
more what the migration achieves, what it cannot achieve or why a migration is not possible.