From c9fc2af6c00d7e00ef7d16815654d3cdcc9961af Mon Sep 17 00:00:00 2001
From: Dimitrij Denissenko <dimitrij.denissenko@blacksquaremedia.com>
Date: Tue, 3 Oct 2017 13:06:26 +0100
Subject: [PATCH 1/2] Add test for snapshot

---
 db_test.go | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/db_test.go b/db_test.go
index 8f5ad543a..30ecf26f3 100644
--- a/db_test.go
+++ b/db_test.go
@@ -312,6 +312,48 @@ func TestSkippingInvalidValuesInSameTxn(t *testing.T) {
 	require.NoError(t, q.Close())
 }
 
+func TestDB_Snapshot(t *testing.T) {
+	db, close := openTestDB(t, nil)
+	defer close()
+
+	// append data
+	app := db.Appender()
+	mint := int64(1414141414000)
+	for i := 0; i < 1000; i++ {
+		_, err := app.Add(labels.FromStrings("foo", "bar"), mint+int64(i), 1.0)
+		require.NoError(t, err)
+	}
+	require.NoError(t, app.Commit())
+	require.NoError(t, app.Rollback())
+
+	// create snapshot
+	snap, err := ioutil.TempDir("", "snap")
+	require.NoError(t, err)
+	require.NoError(t, db.Snapshot(snap))
+	require.NoError(t, db.Close())
+
+	// reopen DB from snapshot
+	db, err = Open(snap, nil, nil, nil)
+	require.NoError(t, err)
+
+	querier := db.Querier(mint, mint+1000)
+	defer querier.Close()
+
+	// sum values
+	seriesSet := querier.Select(labels.NewEqualMatcher("foo", "bar"))
+	sum := 0.0
+	for seriesSet.Next() {
+		series := seriesSet.At().Iterator()
+		for series.Next() {
+			_, v := series.At()
+			sum += v
+		}
+		require.NoError(t, series.Err())
+	}
+	require.NoError(t, seriesSet.Err())
+	require.Equal(t, sum, 1000.0)
+}
+
 func TestDB_e2e(t *testing.T) {
 	const (
 		numDatapoints = 1000

From 203012169adc56dd43986f74d1979f45f9bffbcd Mon Sep 17 00:00:00 2001
From: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
Date: Wed, 4 Oct 2017 16:58:07 +0530
Subject: [PATCH 2/2] snapshot: Remove truncation check to restore func.

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
---
 head.go      | 3 ---
 head_test.go | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/head.go b/head.go
index 00f51e007..82a3459bd 100644
--- a/head.go
+++ b/head.go
@@ -249,9 +249,6 @@ func (h *Head) ReadWAL() error {
 func (h *Head) Truncate(mint int64) error {
 	initialize := h.MinTime() == math.MinInt64
 
-	if mint%h.chunkRange != 0 {
-		return errors.Errorf("truncating at %d not aligned", mint)
-	}
 	if h.MinTime() >= mint {
 		return nil
 	}
diff --git a/head_test.go b/head_test.go
index b7603e78e..31713b9c1 100644
--- a/head_test.go
+++ b/head_test.go
@@ -187,8 +187,8 @@ func TestHead_Truncate(t *testing.T) {
 	}
 	s4.chunks = []*memChunk{}
 
-	// Truncation must be aligned.
-	require.Error(t, h.Truncate(1))
+	// Truncation need not be aligned.
+	require.NoError(t, h.Truncate(1))
 
 	h.Truncate(2000)