Include metrics from upstream chat requests#361
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mostlygeek merged 5 commits intomainfrom Oct 26, 2025
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- remove metrics_middleware.go as this wrapper is no longer needed. This also eliminiates double body parsing for the modelID - move metrics parsing to be part of MetricsMonitor - refactor how metrics are recording in ProxyManager
WalkthroughThe diff removes the Gin middleware-based metrics capture file and refactors metrics into an unexported metricsMonitor with a handler-wrapping approach; ProxyManager is updated to use the new metrics wrapping for relevant POST proxy paths and route-level middleware is removed. Changes
Sequence Diagram(s)sequenceDiagram
participant Client
participant ProxyManager
participant MetricsMonitor
participant Upstream
Client->>ProxyManager: HTTP POST request
alt metricsMonitor present
ProxyManager->>MetricsMonitor: wrapHandler(modelID, wrappedWriter, req)
MetricsMonitor->>MetricsMonitor: wrap response writer (responseBodyCopier)
MetricsMonitor->>ProxyManager: call next handler with wrapped writer
ProxyManager->>Upstream: forward request
Upstream-->>ProxyManager: Response (JSON or SSE)
ProxyManager-->>MetricsMonitor: response flows through responseBodyCopier
MetricsMonitor->>MetricsMonitor: parse metrics (streaming or non-streaming)
MetricsMonitor->>MetricsMonitor: record TokenMetrics & emit event
MetricsMonitor-->>Client: proxied response returned
else no metricsMonitor
ProxyManager->>Upstream: forward request directly
Upstream-->>Client: proxied response returned
end
Estimated code review effort🎯 3 (Moderate) | ⏱️ ~25 minutes
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✅ Passed checks (2 passed)
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Actionable comments posted: 3
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⚠️ Outside diff range comments (2)
proxy/proxymanager.go (1)
488-488: Typo in error message.Use “read” instead of “ready”.
- pm.sendErrorResponse(c, http.StatusBadRequest, "could not ready request body") + pm.sendErrorResponse(c, http.StatusBadRequest, "could not read request body")proxy/metrics_monitor.go (1)
63-75: Avoid emitting events under the write lock (deadlock risk).Handlers may reenter MetricsMonitor (e.g., GetMetrics), causing self-deadlock. Emit after unlocking.
func (mp *MetricsMonitor) addMetrics(metric TokenMetrics) { - mp.mu.Lock() - defer mp.mu.Unlock() - - metric.ID = mp.nextID - mp.nextID++ - mp.metrics = append(mp.metrics, metric) - if len(mp.metrics) > mp.maxMetrics { - mp.metrics = mp.metrics[len(mp.metrics)-mp.maxMetrics:] - } - event.Emit(TokenMetricsEvent{Metrics: metric}) + mp.mu.Lock() + metric.ID = mp.nextID + mp.nextID++ + mp.metrics = append(mp.metrics, metric) + if len(mp.metrics) > mp.maxMetrics { + mp.metrics = mp.metrics[len(mp.metrics)-mp.maxMetrics:] + } + mp.mu.Unlock() + event.Emit(TokenMetricsEvent{Metrics: metric}) }
🧹 Nitpick comments (5)
proxy/proxymanager.go (2)
659-665: Consider metrics for multipart endpoints too.proxyOAIPostFormHandler doesn’t record metrics. If upstream returns usage/timings for audio/transcriptions, wrap this path as well.
- if err := processGroup.ProxyRequest(realModelName, c.Writer, modifiedReq); err != nil { + if pm.metricsMonitor != nil { + if err := pm.metricsMonitor.WrapHandler(realModelName, c.Writer, modifiedReq, processGroup.ProxyRequest); err != nil { + if !c.Writer.Written() { + pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying metrics wrapped request: %s", err.Error())) + } + pm.proxyLogger.Errorf("Error Proxying Metrics Wrapped Request for processGroup %s and model %s: %v", processGroup.id, realModelName, err) + return + } + return + } + if err := processGroup.ProxyRequest(realModelName, c.Writer, modifiedReq); err != nil { pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error())) pm.proxyLogger.Errorf("Error Proxying Request for processGroup %s and model %s", processGroup.id, realModelName) return }
402-404: CORS correctness: add Vary: Origin.Responses vary by Origin; add Vary to enable proper caching behavior.
if origin := c.GetHeader("Origin"); origin != "" { c.Header("Access-Control-Allow-Origin", origin) + c.Header("Vary", "Origin") }proxy/metrics_monitor.go (2)
244-251: Capture WriteString too, otherwise some writes bypass the buffer.Upstream may call WriteString; without overriding it, body capture can be incomplete.
func (w *ResponseBodyCopier) Write(b []byte) (int, error) { if w.start.IsZero() { w.start = time.Now() } // Single write operation that writes to both the response and buffer return w.tee.Write(b) } +func (w *ResponseBodyCopier) WriteString(s string) (int, error) { + if w.start.IsZero() { + w.start = time.Now() + } + return w.tee.Write([]byte(s)) +}
134-178: Memory risk: buffering entire SSE response.ResponseBodyCopier stores full streaming bodies; long chats can exhaust memory. Consider incremental SSE parsing (track only last valid data: line) or apply a bounded ring buffer for SSE content.
If helpful, I can prototype a minimal rolling window parser that processes chunks as they stream and retains only the last data: JSON block.
proxy/metrics_monitor_test.go (1)
345-364: Update expectations if WrapHandler stops surfacing parse errors.If you adopt the non-breaking WrapHandler behavior (only propagate next() errors), change these cases to assert no error and no metrics recorded.
Examples:
- Lines 345-364 “invalid JSON”: replace assert.Error with assert.NoError and assert.Len(mm.GetMetrics(), 0).
- Lines 651-654 “no valid JSON data found in stream”: same.
- Lines 385-405 “response without usage or timings”: same.
Also applies to: 651-654, 385-405
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📒 Files selected for processing (4)
proxy/metrics_middleware.go(0 hunks)proxy/metrics_monitor.go(2 hunks)proxy/metrics_monitor_test.go(1 hunks)proxy/proxymanager.go(3 hunks)
💤 Files with no reviewable changes (1)
- proxy/metrics_middleware.go
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📓 Path-based instructions (1)
**/*.go
📄 CodeRabbit inference engine (CLAUDE.md)
Fix all staticcheck-reported issues in Go code
Files:
proxy/proxymanager.goproxy/metrics_monitor.goproxy/metrics_monitor_test.go
🧬 Code graph analysis (1)
proxy/metrics_monitor_test.go (3)
proxy/config/config.go (1)
Config(112-132)proxy/metrics_monitor.go (4)
NewMetricsMonitor(49-60)TokenMetrics(20-30)TokenMetricsEvent(33-35)NewMetricsBodyRecorder(235-242)event/default.go (1)
On(16-18)
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mostlygeek
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Nov 21, 2025
* proxy: refactor metrics recording - remove metrics_middleware.go as this wrapper is no longer needed. This also eliminiates double body parsing for the modelID - move metrics parsing to be part of MetricsMonitor - refactor how metrics are recording in ProxyManager - add MetricsMonitor tests - improve mem efficiency of processStreamingResponse - add benchmarks for MetricsMonitor.addMetrics - proxy: refactor MetricsMonitor to be more safe handling errors
Merged
This was referenced Feb 5, 2026
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This PR watches the
/upstream/{model}/...endpoints for chat requests and includes them on the activity page.Summary by CodeRabbit