From 1b2fa645ee42161ecaf3b05964952a3c88c90eb8 Mon Sep 17 00:00:00 2001
From: "Jonathan A. Sternberg" <jonathan@influxdb.com>
Date: Wed, 2 Nov 2016 13:35:22 -0500
Subject: [PATCH] Fix incorrect grouping when multiple aggregates are used with
 sparse data

When a query would use a grouping with two different aggregates, it was
possible for one of the aggregates to return a value from a different
series key than the second aggregate. When these series keys didn't
match, the returned grouping would be screwed up because it sorted by
time before checking for name and tags.

This did not happen when the aggregates returned values for the same
series keys because then the iterators were aligned with each other.
---
 CHANGELOG.md                   |  1 +
 cmd/influxd/run/server_test.go | 42 ++++++++++++++++++++++++++++++++++
 influxql/emitter.go            |  4 ++--
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d3f2f4ce63..9d39d5a9d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -75,6 +75,7 @@ The query language has been extended with a few new features:
 - [#7494](https://github.com/influxdata/influxdb/issues/7494): influx_inspect: export does not escape field keys.
 - [#7526](https://github.com/influxdata/influxdb/issues/7526): Truncate the version string when linking to the documentation.
 - [#7548](https://github.com/influxdata/influxdb/issues/7548): Fix output duration units for SHOW QUERIES.
+- [#7564](https://github.com/influxdata/influxdb/issues/7564): Fix incorrect grouping when multiple aggregates are used with sparse data.
 
 ## v1.0.2 [2016-10-05]
 
diff --git a/cmd/influxd/run/server_test.go b/cmd/influxd/run/server_test.go
index 032d3f92e8..95c544c05d 100644
--- a/cmd/influxd/run/server_test.go
+++ b/cmd/influxd/run/server_test.go
@@ -2670,6 +2670,48 @@ cpu value=20 1278010021000000000
 	}
 }
 
+func TestServer_Query_SelectGroupByTime_MultipleAggregates(t *testing.T) {
+	t.Parallel()
+	s := OpenServer(NewConfig())
+	defer s.Close()
+
+	test := NewTest("db0", "rp0")
+	test.writes = Writes{
+		&Write{data: fmt.Sprintf(`test,t=a x=1i 1000000000
+test,t=b y=1i 1000000000
+test,t=a x=2i 2000000000
+test,t=b y=2i 2000000000
+test,t=a x=3i 3000000000
+test,t=b y=3i 3000000000
+`)},
+	}
+
+	test.addQueries([]*Query{
+		&Query{
+			name:    "two aggregates with a group by host",
+			command: `SELECT mean(x) as x, mean(y) as y from db0.rp0.test where time >= 1s and time < 4s group by t, time(1s)`,
+			exp:     `{"results":[{"series":[{"name":"test","tags":{"t":"a"},"columns":["time","x","y"],"values":[["1970-01-01T00:00:01Z",1,null],["1970-01-01T00:00:02Z",2,null],["1970-01-01T00:00:03Z",3,null]]},{"name":"test","tags":{"t":"b"},"columns":["time","x","y"],"values":[["1970-01-01T00:00:01Z",null,1],["1970-01-01T00:00:02Z",null,2],["1970-01-01T00:00:03Z",null,3]]}]}]}`,
+		},
+	}...)
+
+	for i, query := range test.queries {
+		if i == 0 {
+			if err := test.init(s); err != nil {
+				t.Fatalf("test init failed: %s", err)
+			}
+		}
+		if query.skip {
+			t.Logf("SKIP:: %s", query.name)
+			continue
+		}
+		if err := query.Execute(s); err != nil {
+			t.Error(query.Error(err))
+		} else if !query.success() {
+			t.Error(query.failureMessage())
+		}
+	}
+}
+
 func TestServer_Query_MathWithFill(t *testing.T) {
 	t.Parallel()
 	s := OpenServer(NewConfig())
diff --git a/influxql/emitter.go b/influxql/emitter.go
index 2759ba6d8e..e7919a3737 100644
--- a/influxql/emitter.go
+++ b/influxql/emitter.go
@@ -113,14 +113,14 @@ func (e *Emitter) loadBuf() (t int64, name string, tags Tags, err error) {
 
 		// Update range values if lower and emitter is in time ascending order.
 		if e.ascending {
-			if (itrTime < t) || (itrTime == t && itrName < name) || (itrTime == t && itrName == name && itrTags.ID() < tags.ID()) {
+			if (itrName < name) || (itrName == name && itrTags.ID() < tags.ID()) || (itrName == name && itrTags.ID() == tags.ID() && itrTime < t) {
 				t, name, tags = itrTime, itrName, itrTags
 			}
 			continue
 		}
 
 		// Update range values if higher and emitter is in time descending order.
-		if (itrTime > t) || (itrTime == t && itrName > name) || (itrTime == t && itrName == name && itrTags.ID() > tags.ID()) {
+		if (itrName < name) || (itrName == name && itrTags.ID() < tags.ID()) || (itrName == name && itrTags.ID() == tags.ID() && itrTime < t) {
 			t, name, tags = itrTime, itrName, itrTags
 		}
 	}