erigondb.toml Integration Test Plan

Verify that erigondb.toml settings are correctly resolved across three distinct runtime scenarios: legacy datadirs, fresh sync with downloader, and fresh sync without downloader.

Use this plan after any changes to the erigondb.toml resolution logic (creation, defaults, legacy detection, downloader delivery) to confirm all paths still work.

Parameters

Two values must be provided by the caller:

All scenarios use --prune.mode=archive.

Pre-requisites

1. Built binary — invoke /erigon-build if ./build/bin/erigon does not exist.
2. Legacy datadir — the user-provided path must contain snapshots/preverified.toml and must not contain snapshots/erigondb.toml.
3. Port availability — use /erigon-network-ports for reference. Each scenario uses a different port offset (+100, +200, +300) via /erigon-ephemeral conflict detection.

Scenario A: Legacy datadir

Goal: Starting on a legacy datadir (has preverified.toml, no erigondb.toml) creates erigondb.toml with legacy settings (step_size = 1562500).

Steps

1. Create an ephemeral clone of the user's legacy datadir using /erigon-ephemeral (Mode B: clone). This gives an isolated copy so the original is untouched.
2. Confirm pre-conditions on the clone:
   • snapshots/preverified.toml exists
   • snapshots/erigondb.toml does not exist
3. Start erigon with port offset +100 (via /erigon-ephemeral port conflict detection):

   ./build/bin/erigon \
     --datadir=<clone-path> \
     --chain=<chain> \
     --prune.mode=archive \
     <port flags at +100 offset>
   

4. Wait for startup (~15s). Check logs for a message indicating legacy settings detection (e.g., Creating erigondb.toml with LEGACY settings).
5. Verify the generated file:

   cat <clone-path>/snapshots/erigondb.toml
   

   Expected: step_size = 1562500 and references_in_commitment_branches = true
6. Kill the process and clean up the ephemeral datadir.

Scenario B: Fresh sync with downloader

Goal: A fresh datadir (no preverified.toml, no erigondb.toml) starts with code defaults (step_size = 1562500), then the downloader delivers the network's erigondb.toml during the header-chain phase, which may have different settings (e.g., step_size = 390625 for hoodi).

Steps

1. Create an empty ephemeral datadir using /erigon-ephemeral (Mode A: empty).
2. Start erigon with port offset +200:

   ./build/bin/erigon \
     --datadir=<empty-path> \
     --chain=<chain> \
     --prune.mode=archive \
     <port flags at +200 offset>
   

3. Check early logs for a message indicating defaults are being used (e.g., erigondb.toml not found, using defaults) with step_size=1562500.
4. Wait for the header-chain download phase to complete (~30-120s depending on network). Watch logs for:
   • [1/6 OtterSync] Downloader completed header-chain
   • Reading DB settings from existing erigondb.toml
   • erigondb stepSize changed, propagating (if the network's settings differ from the code defaults)
5. Verify the delivered file:

   cat <empty-path>/snapshots/erigondb.toml
   

   The values come from the network's published erigondb.toml (check the chain's webseed for the canonical values).
6. Kill the process and clean up the ephemeral datadir.

Scenario C: Fresh sync with --no-downloader

Goal: A fresh datadir with --no-downloader immediately writes erigondb.toml with code defaults (step_size = 1562500).

Steps

1. Create an empty ephemeral datadir using /erigon-ephemeral (Mode A: empty).
2. Start erigon with port offset +300 and --no-downloader:

   ./build/bin/erigon \
     --datadir=<empty-path> \
     --chain=<chain> \
     --prune.mode=archive \
     --no-downloader \
     <port flags at +300 offset>
   

3. Check logs for a message indicating defaults were written immediately (e.g., Initializing erigondb.toml with DEFAULT settings) with step_size=1562500.
4. Verify the file exists immediately:

   cat <empty-path>/snapshots/erigondb.toml
   

   Expected: step_size = 1562500 and references_in_commitment_branches = true (code defaults, since no downloader to provide network settings)
5. Kill the process and clean up the ephemeral datadir.

Success Criteria

references_in_commitment_branches per scenario

The references_in_commitment_branches field governs whether new commitment merges write referenced (short-key) .kv files. It resolves identically to step_size across the three scenarios — absent field normalizes to true in memory, and a downloaded erigondb.toml is never rewritten (it is synced snapshot metadata, so a producer's published false survives). The resolution logic is unit-tested in db/state/erigondb_settings_test.go (TestResolveErigonDBSettings*); these runtime scenarios confirm the same behavior end-to-end.

• A (legacy): the generated file contains references_in_commitment_branches = true.
• B (fresh+downloader): no file until the downloader delivers it; the in-memory resolved value is true. After delivery the field reflects the network's published value (a plain-snapshot producer ships false).
• C (fresh+no-downloader): the immediately-written file contains references_in_commitment_branches = true.

Producer workflow: publishing plain (unreferenced) snapshots

references_in_commitment_branches governs only new commitment merges; reads are version-aware and stay correct regardless of the flag (a v2.0 commitment .kv whose range ≥ threshold is referenced/short-key; a v2.1 file is plain). To publish a snapshot set whose commitment files carry no plain-key references:

1. In the producer datadir's snapshots/erigondb.toml, set references_in_commitment_branches = false before running merges.
2. Run the node / merge so commitment merges produce plain v2.2 .kv files. Existing v2.1 referenced files convert to plain lazily as they are merged — no upfront migration.
3. Ship the datadir's erigondb.toml with the snapshot set. Consumers read the file and inherit false; a downloaded erigondb.toml is never rewritten, so the producer's false survives.

This supersedes the build-time const flip (awskii/36exp): no binary divergence and no CLI flag. Default nodes (field absent → true) keep writing byte-compatible v2.1 referenced files with no behavior change.

Cleanup

After all scenarios complete, ensure all ephemeral datadirs and processes are cleaned up. Use /erigon-ephemeral Step 5 (cleanup) for each instance, or Step 6 (leftover detection) to find any stragglers.