Operations Framework: Diagrams

This page contains visual diagrams explaining how Operations Framework works.

High-Level Architecture

Command Execution Pipeline:

Class	Description
OperationReprocessor	Retries commands that fail with transient errors
TransientOperationScopeProvider	Provides transient operation scope
DbOperationScopeProvider	Provides DB-backed operation scope
DeferredInvalidationScopeProvider	Opens the deferred invalidation scope
OperationCompletionHandler	Applies the invalidation calls an operation recorded

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
DbOperationCompletionListener<TDbContext>	Notifies log watchers when an operation completes locally
NpgsqlDbLogWatcher<TDbContext, TDbEntry>	Listens for NOTIFY signals
RedisDbLogWatcher	Subscribes to Redis pub/sub
FileSystemDbLogWatcher	Watches for file changes

Command Execution Flow

Handler	Priority	Responsibility
InvalidationGuard	999,999,000	Rejects a nested command run inside an invalidation pass
OperationReprocessor	100,000	Retries commands that fail with transient errors
TransientOperationScopeProvider	10,000	Transient scope, completion handling
DbOperationScopeProvider	9,900	DB transaction, operation persistence
DeferredInvalidationScopeProvider	9,000	Deferred invalidation scope
CompletionTerminator	-1,000,000,000	Terminal handler for ICompletion

Operation Scope Lifecycle

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