When Kubernetes performs rolling deployments, the old pod gracefully shuts down
and Oban's internal processes receive EXIT :shutdown signals. These are logged
as "unexpected" even though they're normal during shutdown.
Added custom logger filter to drop these messages in production:
- Oban.Queue.Watchman/Producer receiving EXIT :shutdown
- Oban plugin processes receiving EXIT :shutdown
- Reduces log noise during deployments without hiding real errors
The filter is production-only to preserve full debugging in development.
Redix expects host to be a string, not a charlist. The to_charlist/1
conversion was causing FunctionClauseError in Redix.StartOptions.__validate_host__/1.
This matches how Phoenix PubSub Redis and Exq are configured, which both
use the string host directly without conversion.
Fixed dialyzer warnings across multiple files by properly handling return
values from functions that are called for side effects.
Changes:
- lib/towerops/agents.ex: Explicitly match broadcast and if-expression returns
- lib/towerops/devices.ex: Match worker start function returns in if-expressions
- lib/towerops/workers/agent_latency_evaluator.ex: Match broadcast return
- lib/towerops/workers/device_monitor_worker.ex: Match perform_check and handle_status_change returns, handle schedule_next_check errors
- lib/towerops/workers/device_poller_worker.ex: Match all PubSub broadcast returns, handle schedule_next_poll errors, remove unreachable pattern
- lib/towerops/workers/stale_agent_worker.ex: Match process_stale_agents and broadcast returns
- lib/towerops_web/channels/agent_channel.ex: Match PubSub.subscribe return, improve get_addr pattern matching, remove unreachable format_ip clause
- lib/towerops_web/live/device_live/form.ex: Match enqueue_discovery return, replace compile-time @dev_env with runtime check
Pattern applied:
- PubSub broadcasts: `_ = Phoenix.PubSub.broadcast(...)`
- If-expressions with side effects: `_ = if condition do ... end`
- Critical operations: Added error logging with case statements
All 3625 tests passing. No dialyzer warnings remaining in lib/towerops or lib/towerops_web.
🤖 Generated with Claude Code
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Changed discover_all/1 to enqueue individual Oban jobs instead of using
Task.async_stream for better error visibility and resilience.
Benefits:
- Errors are visible in Oban dashboard with full stack traces
- Automatic retries on failure via Oban
- Jobs persist across pod restarts
- No more silent failures from Task crashes
- Better concurrency control via Oban queue configuration
Changes:
- discover_all/1 now enqueues DiscoveryWorker jobs and returns immediately
- Return type changed from %{success, failed, errors} to %{enqueued, failed, errors}
- Updated tests to match new async behavior
- Added DiscoveryWorker alias to Discovery module
All tests passing (3,625 tests, 0 failures).
The health check endpoint was calling Towerops.RedisHealthCheck.check_health/2
but the module didn't exist, causing startup probes to fail with 503 errors.
Added RedisHealthCheck module with:
- check_health/2: Single PING command with timeout for health checks
- wait_for_redis/2: Exponential backoff retry logic for startup
This fixes the failing health checks that were blocking pod rollouts.
All tests passing.
Replaced GenServer-based periodic workers with Oban Cron jobs to improve
pod rollover resilience and simplify architecture.
Worker Changes:
- NeighborCleanupWorker: GenServer → Oban Cron (hourly)
- Cleans stale neighbors, ARP entries, and MAC addresses
- Runs every hour via Oban.Plugins.Cron
- StaleAgentWorker: GenServer → Oban Cron (every minute)
- Detects agents that haven't checked in for 10+ minutes
- Refactored to reduce nesting (extracted helper functions)
- Removed stateful tracking (now stateless, re-evaluates each run)
- AgentLatencyEvaluator: GenServer → Oban Cron (every 5 minutes)
- Latency-based agent reassignment with 20% threshold
- Removed trigger_evaluation/0 (no longer needed)
- JobHealthCheckWorker: NEW Oban Cron worker (every 10 minutes)
- Safety net to recover missing monitor/poller jobs
- Auto-creates jobs for devices with monitoring/SNMP enabled
Infrastructure Changes:
- Removed Monitoring.Supervisor (no longer needed)
- Updated application.ex to remove GenServer workers from supervision tree
- Added Oban.Plugins.Cron to dev.exs and runtime.exs
- All workers now run cluster-wide via PostgreSQL-backed coordination
Test Updates:
- Updated all worker tests to call perform(%Oban.Job{args: %{}})
- Removed GenServer lifecycle tests (start_link, send messages, etc.)
- Removed async sleep calls (no longer needed)
Benefits:
- Better pod rollover resilience (Cron jobs run cluster-wide)
- Simpler architecture (no GenServers for periodic tasks)
- Better observability (all jobs visible in Oban dashboard)
- Safety net for missing jobs (JobHealthCheckWorker)
- Stateless workers (easier to reason about and test)
Documentation:
- Updated CLAUDE.md with Background Job Architecture section
- Documented job types, queues, and resilience features
All tests passing (3,686 tests, 0 failures).
Replaces etcd-based distributed locking with Oban's PostgreSQL-backed job queue.
This simplifies the architecture by eliminating the need for a separate etcd cluster
while providing better reliability and observability.
Changes:
- Add Oban dependency and migration (oban_jobs table)
- Create DevicePollerCoordinator and DeviceMonitorCoordinator Oban workers
- Remove EtcdCoordinator and EtcdLock modules
- Update application supervisor to start Oban
- Configure Oban with pollers (50 workers) and monitors (50 workers) queues
- Remove etcd StatefulSet from Kubernetes manifests
- Update monitoring supervisor documentation
Benefits:
- Simpler architecture (no etcd cluster to manage)
- PostgreSQL-based (uses existing database)
- Built-in uniqueness prevents duplicate jobs cluster-wide
- Better observability with Oban Web UI
- Automatic job rescue on node crashes
- Easier local development (no etcd required)
What was removed:
- etcd StatefulSet (3 pods)
- EtcdCoordinator module (320 lines)
- EtcdLock module (158 lines)
- eetcd dependency
All 3,686 tests passing.
Fixes two production issues:
1. NOAUTH Redis authentication error:
- application.ex: Read password from application config
- exq_supervisor.ex: Read password from application config
- Both were bypassing runtime.exs config by reading env directly
2. EtcdCoordinator FunctionClauseError:
- connect_etcd/0 now returns connection name (:towerops_etcd)
- eetcd functions expect the atom name, not the PID
- Fixes crash when trying to acquire locks
The app was crashing when the etcd watcher couldn't be created, even
though 2/3 etcd nodes were healthy and the connection succeeded.
Changes:
- Made watcher creation optional (nil if it fails)
- App now starts successfully even if watcher is unavailable
- Falls back to periodic rebalancing (60s intervals) instead of instant failover
- Changed error level from error to warning when watcher creation fails
- Added helpful context to warning message
This allows the app to run with degraded performance instead of crashing
completely when there are etcd cluster issues.
🤖 Generated with Claude Code
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
The pods were crashing with a MatchError when the etcd watcher failed
to initialize. The code was pattern matching on {:ok, watcher} but
eetcd was returning {:error, :eetcd_conn_unavailable}.
Error:
** (MatchError) no match of right hand side value:
{:error, :eetcd_conn_unavailable}
This was causing CrashLoopBackOff because the application couldn't
start the Monitoring.Supervisor due to EtcdCoordinator initialization
failure.
Fix:
- Add case statement to handle both {:ok, watcher} and {:error, reason}
- Log the specific error when watcher creation fails
- Return proper error tuple to supervisor for clean shutdown
The :eetcd Erlang library expects charlists, not binary strings.
This was causing a FunctionClauseError in :lists.reverse/1 because
it was receiving a binary string instead of a charlist.
Error:
(FunctionClauseError) no function clause matching in :lists.reverse/1
(stdlib 7.2) lists.erl:291: :lists.reverse("etcd-0.etcd...")
Solution:
Use ~c sigil to convert endpoint strings to charlists for the
Erlang library to consume correctly.
Add REDIS_PASSWORD environment variable support to both Phoenix.PubSub.Redis
and Exq background job processor. Password is optional - if not set, connects
without authentication.
Changes:
- application.ex: Add password to PubSub Redis config if REDIS_PASSWORD is set
- exq_supervisor.ex: Add password to Exq Redis config if REDIS_PASSWORD is set
Required for connecting to Proxmox-hosted Redis with authentication.
