mirror of
https://github.com/rustfs/rustfs.git
synced 2026-08-07 22:03:14 +00:00
Jitter
51 lines
2.5 KiB
Markdown
51 lines
2.5 KiB
Markdown
# Resolution Report: Issue #1001 - Cluster Recovery from Abrupt Power-Off
|
|
|
|
## 1. Issue Description
|
|
**Problem**: The cluster failed to recover gracefully when a node experienced an abrupt power-off (hard failure).
|
|
**Symptoms**:
|
|
- The application became unable to upload files.
|
|
- The Console Web UI became unresponsive across the cluster.
|
|
- The system "hung" indefinitely, unlike the immediate recovery observed during a graceful process termination (`kill`).
|
|
|
|
**Root Cause**:
|
|
The standard TCP protocol does not immediately detect a silent peer disappearance (power loss) because no `FIN` or `RST` packets are sent. Without active application-layer heartbeats, the surviving nodes kept connections implementation in an `ESTABLISHED` state, waiting indefinitely for responses that would never arrive.
|
|
|
|
---
|
|
|
|
## 2. Technical Approach
|
|
To resolve this, we needed to transform the passive failure detection (waiting for TCP timeout) into an active detection mechanism.
|
|
|
|
### Key Objectives:
|
|
1. **Fail Fast**: Detect dead peers in seconds, not minutes.
|
|
2. **Accuracy**: Distinguish between network congestion and actual node failure.
|
|
3. **Safety**: Ensure no thread or task blocks forever on a remote procedure call (RPC).
|
|
|
|
---
|
|
|
|
## 3. Implemented Solution
|
|
We modified the internal gRPC client configuration in `crates/protos/src/lib.rs` to implement a multi-layered health check strategy.
|
|
|
|
### Configuration Changes
|
|
|
|
```rust
|
|
let connector = Endpoint::from_shared(addr.to_string())?
|
|
.connect_timeout(Duration::from_secs(5))
|
|
// 1. App-Layer Heartbeats (Primary Detection)
|
|
// Sends a hidden HTTP/2 PING frame every 5 seconds.
|
|
.http2_keep_alive_interval(Duration::from_secs(5))
|
|
// If PING is not acknowledged within 3 seconds, closes connection.
|
|
.keep_alive_timeout(Duration::from_secs(3))
|
|
// Ensures PINGs are sent even when no active requests are in flight.
|
|
.keep_alive_while_idle(true)
|
|
// 2. Transport-Layer Keepalive (OS Backup)
|
|
.tcp_keepalive(Some(Duration::from_secs(10)))
|
|
// 3. Global Safety Net
|
|
// Hard deadline for any RPC operation.
|
|
.timeout(Duration::from_secs(60));
|
|
```
|
|
|
|
### Outcome
|
|
- **Detection Time**: Reduced from ~15+ minutes (OS default) to **~8 seconds** (5s interval + 3s timeout).
|
|
- **Behavior**: When a node loses power, surviving peers now detect the lost connection almost immediately, throwing a protocol error that triggers standard cluster recovery/failover logic.
|
|
- **Result**: The cluster now handles power-offs with the same resilience as graceful shutdowns.
|