From dd72f6cd6a9242297789a1b964fb0baa6e5df965 Mon Sep 17 00:00:00 2001
From: Oleg Zaytsev <mail@olegzaytsev.com>
Date: Fri, 3 Jan 2025 17:19:47 +0100
Subject: [PATCH] Fix logs, log min/maxt

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
---
 tsdb/head_read.go | 5 ++++-
 tsdb/querier.go   | 6 +++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/tsdb/head_read.go b/tsdb/head_read.go
index f85120a97..b94b44ad9 100644
--- a/tsdb/head_read.go
+++ b/tsdb/head_read.go
@@ -76,7 +76,10 @@ func (h *headIndexReader) SortedLabelValues(ctx context.Context, name string, ma
 // If matchers are specified the returned result set is reduced
 // to label values of metrics matching the matchers.
 func (h *headIndexReader) LabelValues(ctx context.Context, name string, matchers ...*labels.Matcher) ([]string, error) {
-	if h.maxt < h.head.MinTime() || h.mint > h.head.MaxTime() {
+	headMinTime := h.head.MinTime()
+	headMaxTime := h.head.MaxTime()
+	if h.maxt < headMinTime || h.mint > headMaxTime {
+		fmt.Println("Returning empty label values for ", name, "because out of range:", "h.maxt=", h.maxt, "<", headMinTime, "=headMinTime ||  h.mint=", h.mint, " > ", headMaxTime, "=headMaxTime")
 		return []string{}, nil
 	}
 
diff --git a/tsdb/querier.go b/tsdb/querier.go
index fa52c036c..4118ce2b4 100644
--- a/tsdb/querier.go
+++ b/tsdb/querier.go
@@ -214,13 +214,17 @@ func PostingsForMatchers(ctx context.Context, ix IndexPostingsReader, ms ...*lab
 		}
 		return fmt.Sprintf("%T", p)
 	}
+	if hr, ok := ix.(*headIndexReader); ok {
+		debug("h.maxt=%d, h.mint=%d", hr.maxt, hr.mint)
+		debug("h.head.MaxTime=%d, h.head.MinTime=%d", hr.head.MaxTime(), hr.head.MinTime())
+	}
 
 	var its, notIts []index.Postings
 	if troubleshoot {
 		defer func() {
 			selector := (&parser.VectorSelector{LabelMatchers: ms}).String()
 			traceID := trace.SpanFromContext(ctx).SpanContext().TraceID().String()
-			fmt.Printf("PostingsForMatchers(ix=%T, ms=%s, traceID=%s): %s", ix, selector, traceID, strings.Join(troubleshootData, ", "))
+			fmt.Printf("PostingsForMatchers(ix=%T, ms=%s, traceID=%s): %s\n", ix, selector, traceID, strings.Join(troubleshootData, ", "))
 		}()
 	}
 	// See which label must be non-empty.