From 039fc80ed790302e94fcb57605e4ef103ad3aea3 Mon Sep 17 00:00:00 2001 From: Maksim Naumov Date: Mon, 22 Jun 2015 04:27:46 +0200 Subject: [PATCH 1/2] Memcached plugin --- plugins/memcached/memcached.go | 148 ++++++++++++++++++++++++++++ plugins/memcached/memcached_test.go | 31 ++++++ 2 files changed, 179 insertions(+) create mode 100644 plugins/memcached/memcached.go create mode 100644 plugins/memcached/memcached_test.go diff --git a/plugins/memcached/memcached.go b/plugins/memcached/memcached.go new file mode 100644 index 000000000..9de2a5959 --- /dev/null +++ b/plugins/memcached/memcached.go @@ -0,0 +1,148 @@ +package memcached + +import ( + "bufio" + "bytes" + "fmt" + "net" + "strconv" + "time" + + "github.com/influxdb/telegraf/plugins" +) + +// Memcached is a memcached plugin +type Memcached struct { + Servers []string +} + +var sampleConfig = ` +# An array of address to gather stats about. Specify an ip on hostname +# with optional port. ie localhost, 10.0.0.1:11211, etc. +# +# If no servers are specified, then localhost is used as the host. +servers = ["localhost"]` + +var defaultTimeout = 5 * time.Second + +// The list of metrics tha should be calculated +var sendAsIs = []string{ + "get_hits", + "get_misses", + "evictions", +} + +// SampleConfig returns sample configuration message +func (m *Memcached) SampleConfig() string { + return sampleConfig +} + +// Description returns description of Memcached plugin +func (m *Memcached) Description() string { + return "Read metrics from one or many memcached servers" +} + +// Gather reads stats from all configured servers accumulates stats +func (m *Memcached) Gather(acc plugins.Accumulator) error { + if len(m.Servers) == 0 { + return m.gatherServer(":11211", acc) + } + + for _, serverAddress := range m.Servers { + if err := m.gatherServer(serverAddress, acc); err != nil { + return err + } + } + + return nil +} + +func (m *Memcached) gatherServer(address string, acc plugins.Accumulator) error { + _, _, err := net.SplitHostPort(address) + if err != nil { + address = address + ":11211" + } + + // Connect + conn, err := net.DialTimeout("tcp", address, defaultTimeout) + if err != nil { + return err + } + defer conn.Close() + + // Extend connection + conn.SetDeadline(time.Now().Add(defaultTimeout)) + + // Read and write buffer + rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn)) + + // Send command + if _, err = fmt.Fprint(rw, "stats\r\n"); err != nil { + return err + } + if err = rw.Flush(); err != nil { + return err + } + + // Read response + values := make(map[string]string) + + for { + // Read line + line, _, errRead := rw.Reader.ReadLine() + if errRead != nil { + return errRead + } + // Done + if bytes.Equal(line, []byte("END")) { + break + } + // Read values + var name, value string + n, errScan := fmt.Sscanf(string(line), "STAT %s %s\r\n", &name, &value) + if errScan != nil || n != 2 { + return fmt.Errorf("unexpected line in stats response: %q", line) + } + + // Save values + values[name] = value + } + + // + tags := map[string]string{"server": address} + + // Process values + for _, key := range sendAsIs { + if value, ok := values[key]; ok { + // Mostly it is the number + if iValue, errParse := strconv.ParseInt(value, 10, 64); errParse != nil { + acc.Add(key, value, tags) + } else { + acc.Add(key, iValue, tags) + } + } + } + + // Usage + acc.Add("usage", m.calcUsage(values), tags) + return nil +} + +func (m *Memcached) calcUsage(values map[string]string) float64 { + maxBytes, maxOk := values["limit_maxbytes"] + bytes, bytesOk := values["bytes"] + if maxOk && bytesOk { + if fMax, errMax := strconv.ParseFloat(maxBytes, 64); errMax == nil && fMax > 0 { + if fBytes, errBytes := strconv.ParseFloat(bytes, 64); errBytes == nil { + return fBytes / fMax + } + } + } + return 0 +} + +func init() { + plugins.Add("memcached", func() plugins.Plugin { + return &Memcached{} + }) +} diff --git a/plugins/memcached/memcached_test.go b/plugins/memcached/memcached_test.go new file mode 100644 index 000000000..04184fff6 --- /dev/null +++ b/plugins/memcached/memcached_test.go @@ -0,0 +1,31 @@ +package memcached + +import ( + "testing" + + "github.com/influxdb/telegraf/testutil" + "github.com/stretchr/testify/assert" + "github.com/stretchr/testify/require" +) + +func TestMemcachedGeneratesMetrics(t *testing.T) { + m := &Memcached{ + Servers: []string{"localhost"}, + } + + var acc testutil.Accumulator + + err := m.Gather(&acc) + require.NoError(t, err) + + intMetrics := []string{"get_hits", "get_misses", "evictions"} + floatMetrics := []string{"usage"} + + for _, metric := range intMetrics { + assert.True(t, acc.HasIntValue(metric), metric) + } + + for _, metric := range floatMetrics { + assert.True(t, acc.HasFloatValue(metric), metric) + } +} From b86d789abe3f55ff611220fb87be12e42bc632dc Mon Sep 17 00:00:00 2001 From: Maksim Naumov Date: Tue, 23 Jun 2015 09:44:39 +0200 Subject: [PATCH 2/2] Explore "limit_maxbytes" and "bytes" individually --- plugins/memcached/memcached.go | 18 ++---------------- plugins/memcached/memcached_test.go | 7 +------ 2 files changed, 3 insertions(+), 22 deletions(-) diff --git a/plugins/memcached/memcached.go b/plugins/memcached/memcached.go index 9de2a5959..802fae35d 100644 --- a/plugins/memcached/memcached.go +++ b/plugins/memcached/memcached.go @@ -30,6 +30,8 @@ var sendAsIs = []string{ "get_hits", "get_misses", "evictions", + "limit_maxbytes", + "bytes", } // SampleConfig returns sample configuration message @@ -122,25 +124,9 @@ func (m *Memcached) gatherServer(address string, acc plugins.Accumulator) error } } } - - // Usage - acc.Add("usage", m.calcUsage(values), tags) return nil } -func (m *Memcached) calcUsage(values map[string]string) float64 { - maxBytes, maxOk := values["limit_maxbytes"] - bytes, bytesOk := values["bytes"] - if maxOk && bytesOk { - if fMax, errMax := strconv.ParseFloat(maxBytes, 64); errMax == nil && fMax > 0 { - if fBytes, errBytes := strconv.ParseFloat(bytes, 64); errBytes == nil { - return fBytes / fMax - } - } - } - return 0 -} - func init() { plugins.Add("memcached", func() plugins.Plugin { return &Memcached{} diff --git a/plugins/memcached/memcached_test.go b/plugins/memcached/memcached_test.go index 04184fff6..08e696fb7 100644 --- a/plugins/memcached/memcached_test.go +++ b/plugins/memcached/memcached_test.go @@ -18,14 +18,9 @@ func TestMemcachedGeneratesMetrics(t *testing.T) { err := m.Gather(&acc) require.NoError(t, err) - intMetrics := []string{"get_hits", "get_misses", "evictions"} - floatMetrics := []string{"usage"} + intMetrics := []string{"get_hits", "get_misses", "evictions", "limit_maxbytes", "bytes"} for _, metric := range intMetrics { assert.True(t, acc.HasIntValue(metric), metric) } - - for _, metric := range floatMetrics { - assert.True(t, acc.HasFloatValue(metric), metric) - } }