Operations Framework: Diagrams
This page contains visual diagrams explaining how Operations Framework works.
High-Level Architecture
Command Execution Pipeline:
| Class | Description |
|---|---|
NestedOperationLogger | Captures nested command calls |
InMemoryOperationScopeProvider | Provides transient operation scope |
DbOperationScopeProvider | Provides DB-backed operation scope |
InvalidatingCompletionHandler | Runs invalidation for completed operations |
Background Services:
| Class | Description |
|---|---|
DbOperationLogReader | Reads operations from other hosts |
DbOperationLogTrimmer | Removes old operations from log |
DbEventLogReader | Processes pending events |
DbEventLogTrimmer | Removes processed/discarded events |
Notification System:
| Class | Description |
|---|---|
DbOperationCompletionNotifier | Triggers invalidation for replayed operations |
PostgreSqlDbLogWatcher | Listens for NOTIFY signals |
RedisDbLogWatcher | Subscribes to Redis pub/sub |
FileSystemDbLogWatcher | Watches for file changes |
Command Execution Flow
| Handler | Priority | Responsibility |
|---|---|---|
NestedOperationLogger | 11,000 | Captures nested commands, isolates Operation.Items |
InMemoryOperationScopeProvider | 10,000 | Transient scope, completion handling |
DbOperationScopeProvider | 1,000 | DB transaction, operation persistence |
InvalidatingCommandCompletionHandler | 100 | Runs invalidation pass |
Operation Scope Lifecycle
Operation Items vs Context Items
| Property | CommandContext.Items | Operation.Items |
|---|---|---|
| Scope | Single command execution | Operation + invalidation across all hosts |
| Lifetime | Command start → end | Command start → invalidation on all hosts |
| Persistence | In-memory only | Stored in database (JSON) |
| Cross-host | No | Yes |
| Usage | context.Items.Set(...) / Get<T>() | operation.Items.KeylessSet(x) / KeylessGet<T>() |
Multi-Host Invalidation Flow
Event Processing Flow
| Event State | Description |
|---|---|
New | Freshly added, awaiting processing |
Processed | Successfully executed |
Discarded | Failed after max retries |
Log Watcher Comparison
| Watcher Type | Mechanism | Latency | Infrastructure |
|---|---|---|---|
| PostgreSQL NOTIFY | NOTIFY / LISTEN on channel | < 10ms | None (uses DB) |
| Redis Pub/Sub | PUBLISH / SUBSCRIBE on channel | < 1ms | Redis server |
| FileSystem Watcher | Touch file / Watch directory | < 100ms | Shared filesystem |
| No Watcher (Polling) | Poll _Operations table | 0-5s | None |