feat #6679: add series limit config setting

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Config option `[cluster]` has been replaced with `[coordinator]`
 * Support for config options `[collectd]` and `[opentsdb]` has been removed; use `[[collectd]]` and `[[opentsdb]]` instead.
 * Config option `data-logging-enabled` within the `[data]` section, has been renamed to `trace-logging-enabled`, and defaults to `false`.
+* `max-series-per-database` was added with a default of 1M but can be disabled by setting it to `0`.
 
 With this release the systemd configuration files for InfluxDB will use the system configured default for logging and will no longer write files to `/var/log/influxdb` by default. On most systems, the logs will be directed to the systemd journal and can be accessed by `journalctl -u influxdb.service`. Consult the systemd journald documentation for configuring journald.
 
@@ -44,6 +45,7 @@ With this release the systemd configuration files for InfluxDB will use the syst
 - [#7011](https://github.com/influxdata/influxdb/issues/7011): Create man pages for commands.
 - [#7050](https://github.com/influxdata/influxdb/pull/7050): Update go package library dependencies.
 - [#5750](https://github.com/influxdata/influxdb/issues/5750): Support wildcards in aggregate functions.
+- [#7095](https://github.com/influxdata/influxdb/pull/7095): Add MaxSeriesPerDatabase config setting.
 
 ### Bugfixes
 

tsdb/config.go

@@ -36,6 +36,9 @@ const (
 	// DefaultMaxPointsPerBlock is the maximum number of points in an encoded
 	// block in a TSM file
 	DefaultMaxPointsPerBlock = 1000
+
+	// DefaultMaxSeriesPerDatabase is the maximum number of series a node can hold per database.
+	DefaultMaxSeriesPerDatabase = 1000000
 )
 
 // Config holds the configuration for the tsbd package.
@@ -57,6 +60,13 @@ type Config struct {
 	CompactFullWriteColdDuration   toml.Duration `toml:"compact-full-write-cold-duration"`
 	MaxPointsPerBlock              int           `toml:"max-points-per-block"`
 
+	// Limits
+
+	// MaxSeriesPerDatabase is the maximum number of series a node can hold per database.
+	// When this limit is exceeded, writes return a 'max series per database exceeded' error.
+	// A value of 0 disables the limit.
+	MaxSeriesPerDatabase int `toml:"max-series-per-database"`
+
 	TraceLoggingEnabled bool `toml:"trace-logging-enabled"`
 }
 
@@ -74,6 +84,8 @@ func NewConfig() Config {
 		CacheSnapshotWriteColdDuration: toml.Duration(DefaultCacheSnapshotWriteColdDuration),
 		CompactFullWriteColdDuration:   toml.Duration(DefaultCompactFullWriteColdDuration),
 
+		MaxSeriesPerDatabase: DefaultMaxSeriesPerDatabase,
+
 		TraceLoggingEnabled: false,
 	}
 }

tsdb/shard.go

@@ -451,6 +451,10 @@ func (s *Shard) validateSeriesAndFields(points []models.Point) ([]*FieldCreate,
 		key := string(p.Key())
 		ss := s.index.Series(key)
 		if ss == nil {
+			if s.options.Config.MaxSeriesPerDatabase > 0 && len(s.index.series)+1 > s.options.Config.MaxSeriesPerDatabase {
+				return nil, fmt.Errorf("max series per database exceeded: %s", key)
+			}
+
 			ss = NewSeries(key, p.Tags())
 			atomic.AddInt64(&s.stats.SeriesCreated, 1)
 		}

tsdb/shard_test.go

@@ -1,6 +1,7 @@
 package tsdb_test
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -96,6 +97,59 @@ func TestShardWriteAndIndex(t *testing.T) {
 	}
 }
 
+func TestMaxSeriesLimit(t *testing.T) {
+	tmpDir, _ := ioutil.TempDir("", "shard_test")
+	defer os.RemoveAll(tmpDir)
+	tmpShard := path.Join(tmpDir, "shard")
+	tmpWal := path.Join(tmpDir, "wal")
+
+	index := tsdb.NewDatabaseIndex("db")
+	opts := tsdb.NewEngineOptions()
+	opts.Config.WALDir = filepath.Join(tmpDir, "wal")
+	opts.Config.MaxSeriesPerDatabase = 1000
+
+	sh := tsdb.NewShard(1, index, tmpShard, tmpWal, opts)
+
+	if err := sh.Open(); err != nil {
+		t.Fatalf("error opening shard: %s", err.Error())
+	}
+
+	// Writing 1K series should succeed.
+	points := []models.Point{}
+
+	for i := 0; i < 1000; i++ {
+		pt := models.MustNewPoint(
+			"cpu",
+			map[string]string{"host": fmt.Sprintf("server%d", i)},
+			map[string]interface{}{"value": 1.0},
+			time.Unix(1, 2),
+		)
+		points = append(points, pt)
+	}
+
+	err := sh.WritePoints(points)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	// Writing one more series should exceed the series limit.
+	pt := models.MustNewPoint(
+		"cpu",
+		map[string]string{"host": "server9999"},
+		map[string]interface{}{"value": 1.0},
+		time.Unix(1, 2),
+	)
+
+	err = sh.WritePoints([]models.Point{pt})
+	if err == nil {
+		t.Fatal("expected error")
+	} else if err.Error() != "max series per database exceeded: cpu,host=server9999" {
+		t.Fatalf("unexpected error messag:\n\texp = max series per database exceeded: cpu,host=server9999\n\tgot = %s", err.Error())
+	}
+
+	sh.Close()
+}
+
 func TestShardWriteAddNewField(t *testing.T) {
 	tmpDir, _ := ioutil.TempDir("", "shard_test")
 	defer os.RemoveAll(tmpDir)