package memcached import ( "bufio" "bytes" "fmt" "net" "strconv" "time" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/plugins/inputs" ) // Memcached is a memcached plugin type Memcached struct { Servers []string UnixSockets []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. servers = ["localhost:11211"] # unix_sockets = ["/var/run/memcached.sock"] ` var defaultTimeout = 5 * time.Second // The list of metrics that should be sent var sendMetrics = []string{ "get_hits", "get_misses", "evictions", "limit_maxbytes", "bytes", "uptime", "curr_items", "total_items", "curr_connections", "total_connections", "connection_structures", "cmd_get", "cmd_set", "delete_hits", "delete_misses", "incr_hits", "incr_misses", "decr_hits", "decr_misses", "cas_hits", "cas_misses", "bytes_read", "bytes_written", "threads", "conn_yields", } // 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 telegraf.Accumulator) error { if len(m.Servers) == 0 && len(m.UnixSockets) == 0 { return m.gatherServer(":11211", false, acc) } for _, serverAddress := range m.Servers { acc.AddError(m.gatherServer(serverAddress, false, acc)) } for _, unixAddress := range m.UnixSockets { acc.AddError(m.gatherServer(unixAddress, true, acc)) } return nil } func (m *Memcached) gatherServer( address string, unix bool, acc telegraf.Accumulator, ) error { var conn net.Conn var err error if unix { conn, err = net.DialTimeout("unix", address, defaultTimeout) if err != nil { return err } defer conn.Close() } else { _, _, err = net.SplitHostPort(address) if err != nil { address = address + ":11211" } conn, err = net.DialTimeout("tcp", address, defaultTimeout) if err != nil { return err } defer conn.Close() } if conn == nil { return fmt.Errorf("Failed to create net connection") } // 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 } values, err := parseResponse(rw.Reader) if err != nil { return err } // Add server address as a tag tags := map[string]string{"server": address} // Process values fields := make(map[string]interface{}) for _, key := range sendMetrics { if value, ok := values[key]; ok { // Mostly it is the number if iValue, errParse := strconv.ParseInt(value, 10, 64); errParse == nil { fields[key] = iValue } else { fields[key] = value } } } acc.AddFields("memcached", fields, tags) return nil } func parseResponse(r *bufio.Reader) (map[string]string, error) { values := make(map[string]string) for { // Read line line, _, errRead := r.ReadLine() if errRead != nil { return values, errRead } // Done if bytes.Equal(line, []byte("END")) { break } // Read values s := bytes.SplitN(line, []byte(" "), 3) if len(s) != 3 || !bytes.Equal(s[0], []byte("STAT")) { return values, fmt.Errorf("unexpected line in stats response: %q", line) } // Save values values[string(s[1])] = string(s[2]) } return values, nil } func init() { inputs.Add("memcached", func() telegraf.Input { return &Memcached{} }) }