Bug: Functional tests broken since named-channels merge — orchestrator discovery hangs in CI

[renecannao]

Summary

Since the named-channels merge (#77, #78, #79), all functional tests are broken. Orchestrator starts in the Docker container but cannot save discovered instances to the SQLite backend, causing /api/clusters to return empty results.

Symptoms

• Orchestrator starts successfully and logs "Starting HTTP listener on :3099"
• Discover API calls resolve hostnames (mysql1 → mysql1, sees replica IPs 172.30.0.11, 172.30.0.12)
• But /api/clusters returns empty ([]) after 60+ seconds
• Only ~30 lines of orchestrator log in 8+ minutes — the continuous discovery loop appears to stop after the first iteration
• No error messages logged

Last working commit

70065f9d (Merge PR #76, issue74-web-ui-refresh) — functional tests passed in 3m42s

First broken commit

e4d5b2ae (Multi-cluster support: manage MySQL and PostgreSQL simultaneously, #73)

Investigation so far

• Schema migration for provider_type column works correctly on SQLite (verified locally)
• Orchestrator self-elects on local machine (no Docker) without issues
• The discover API handler calls ReadTopologyInstance which connects to MySQL successfully (hostname resolution + replica IPs appear in logs)
• But instance data never appears in backend DB
• The continuous discovery loop seems to stop/block after the first cycle
• Possibly related to SQLite concurrency with the new detectProviderType queries running alongside the write path

To reproduce

go build -o bin/orchestrator ./go/cmd/orchestrator
cd tests/functional
docker compose up -d mysql1 mysql2 mysql3 proxysql
bash setup-replication.sh
docker compose up -d orchestrator
# Wait 30s, then:
curl http://localhost:3099/api/clusters  # Returns []
docker compose logs orchestrator  # Shows only ~30 lines

Impact

All functional CI tests fail on master and all PR branches.

[coderabbitai]

🔗 Related PRs

#51 - Add functional test CI: Docker MySQL topology + ProxySQL + failover tests [merged]
#75 - Multi-cluster support: MySQL and PostgreSQL simultaneously [merged]
#78 - Support MySQL replication named channels (phases 1-3) [merged]

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