mo-service: track active connections

[reusee]

User description

What type of PR is this?

• API-change
• BUG
• Improvement
• Documentation
• Feature
• Test and CI
• Code Refactoring

Which issue(s) this PR fixes:

issue #18725

What this PR does / why we need it:

track connections to help debug.

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PR Type

Enhancement

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Description

• Implemented a new feature to track active connections in the mo-service using the conntrack library.
• Added logging for connection statistics and alerts when the number of connections exceeds a specified threshold.
• Updated go.mod and go.sum to include new dependencies for connection tracking and updated existing dependencies.

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Changes walkthrough 📝

	Relevant files
Enhancement	debug_connections.go Implement active connection tracking and logging                  cmd/mo-service/debug_connections.go Added a new Go file for tracking active connections. Implemented connection tracking using conntrack and netfilter. Logs connection statistics and alerts when connections exceed a threshold. Utilizes goroutines for concurrent processing of connection events. +120/-0
Dependencies	go.mod Update dependencies for connection tracking                            go.mod Added new dependencies for conntrack and netfilter. Updated existing dependencies to newer versions. +10/-4    go.sum Update dependency checksums                                                            go.sum Updated checksums for new and updated dependencies. +22/-10

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PR Reviewer Guide 🔍

⏱️ Estimated effort to review: 3 🔵🔵🔵⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ Key issues to review Performance Concern The connection tracking goroutine runs indefinitely without a way to stop it, which may lead to resource leaks if the service is restarted or needs to be shut down gracefully. Error Handling The error returned from c.Listen() is not properly handled. If an error occurs, the function returns without closing the connection or stopping the goroutine.

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PR Code Suggestions ✨

Category	Suggestion	Score
Best practice	Implement graceful shutdown using context cancellation Consider using a context with cancellation for graceful shutdown. This allows for proper cleanup of resources and goroutine termination when the service is stopped. cmd/mo-service/debug_connections.go [58-64] +ctx, cancel := context.WithCancel(context.Background()) go func() { defer c.Close() + defer cancel() activeConns := make(map[uint32]*conntrack.Flow) ticker := time.NewTicker(time.Second * 7) + defer ticker.Stop() for { select { + case <-ctx.Done(): + return Apply this suggestion Suggestion importance[1-10]: 9 Why: Using a context with cancellation is a best practice for managing goroutines and ensuring resources are properly cleaned up during shutdown, which is crucial for robust service operation.	9
Performance	Use a concurrent map for better performance in high-concurrency scenarios Consider using a more efficient data structure for activeConns, such as a concurrent map (sync.Map) or a custom thread-safe map implementation. This can improve performance in scenarios with high concurrency. cmd/mo-service/debug_connections.go [61] -activeConns := make(map[uint32]*conntrack.Flow) +activeConns := sync.Map{} Apply this suggestion Suggestion importance[1-10]: 8 Why: Switching to a concurrent map like sync.Map can improve performance in high-concurrency scenarios by reducing contention, making it a valuable enhancement for the connection tracking logic.	8
	Reduce the buffer size of the events channel to optimize memory usage Consider using a buffered channel with a smaller capacity for events. The current capacity of 65536 might be excessive and could potentially lead to high memory usage if the channel fills up faster than it can be processed. cmd/mo-service/debug_connections.go [46] -events := make(chan conntrack.Event, 65536) +events := make(chan conntrack.Event, 1024) Apply this suggestion Suggestion importance[1-10]: 7 Why: The suggestion to reduce the buffer size of the events channel is valid as it can help optimize memory usage. However, the exact buffer size should be determined based on expected load and performance testing.	7
Enhancement	Separate thresholds for total connections and per-port connections The tooManyThreshold constant is used for both connection count and individual port statistics. Consider separating these thresholds for more fine-grained control over alerting and logging. cmd/mo-service/debug_connections.go [35-37] const ( - tooManyThreshold = 4096 + tooManyConnectionsThreshold = 4096 + tooManyPortConnectionsThreshold = 409 // 10% of total connections threshold ) Apply this suggestion Suggestion importance[1-10]: 8 Why: Separating thresholds allows for more precise control over connection management and alerting, which can enhance the monitoring and management of network connections.	8