func newFarm(
redisInstances string,
writeQuorumStr string,
connectTimeout, readTimeout, writeTimeout time.Duration,
redisMCPI int,
hash func(string) uint32,
readStrategy farm.ReadStrategy,
repairStrategy farm.RepairStrategy,
maxSize int,
selectGap time.Duration,
instr instrumentation.Instrumentation,
) (*farm.Farm, error) {
clusters, err := farm.ParseFarmString(
redisInstances,
connectTimeout,
readTimeout,
writeTimeout,
redisMCPI,
hash,
maxSize,
selectGap,
instr,
)
if err != nil {
return nil, err
}
log.Printf("%d cluster(s)", len(clusters))
writeQuorum, err := evaluateScalarPercentage(
writeQuorumStr,
len(clusters),
)
if err != nil {
return nil, err
}
return farm.New(
clusters,
writeQuorum,
readStrategy,
repairStrategy,
instr,
), nil
}
func main() {
var (
redisInstances = flag.String("redis.instances", "", "Semicolon-separated list of comma-separated lists of Redis instances")
redisConnectTimeout = flag.Duration("redis.connect.timeout", 3*time.Second, "Redis connect timeout")
redisReadTimeout = flag.Duration("redis.read.timeout", 3*time.Second, "Redis read timeout")
redisWriteTimeout = flag.Duration("redis.write.timeout", 3*time.Second, "Redis write timeout")
redisMCPI = flag.Int("redis.mcpi", 2, "Max connections per Redis instance")
redisHash = flag.String("redis.hash", "murmur3", "Redis hash function: murmur3, fnv, fnva")
selectGap = flag.Duration("select.gap", 0*time.Millisecond, "delay between pipeline read invocations when Selecting over multiple keys")
maxSize = flag.Int("max.size", 10000, "Maximum number of events per key")
batchSize = flag.Int("batch.size", 100, "keys to select per request")
maxKeysPerSecond = flag.Int64("max.keys.per.second", 1000, "max keys per second to walk")
scanLogInterval = flag.Duration("scan.log.interval", 5*time.Second, "how often to report scan rates in log")
once = flag.Bool("once", false, "walk entire keyspace once and exit (default false, walk forever)")
statsdAddress = flag.String("statsd.address", "", "Statsd address (blank to disable)")
statsdSampleRate = flag.Float64("statsd.sample.rate", 0.1, "Statsd sample rate for normal metrics")
statsdBucketPrefix = flag.String("statsd.bucket.prefix", "myservice.", "Statsd bucket key prefix, including trailing period")
prometheusNamespace = flag.String("prometheus.namespace", "roshiwalker", "Prometheus key namespace, excluding trailing punctuation")
prometheusMaxSummaryAge = flag.Duration("prometheus.max.summary.age", 10*time.Second, "Prometheus max age for instantaneous histogram data")
httpAddress = flag.String("http.address", ":6060", "HTTP listen address (profiling/metrics endpoints only)")
)
flag.Parse()
log.SetOutput(os.Stdout)
log.SetFlags(log.Lmicroseconds)
// Validate integer arguments.
if *maxKeysPerSecond < int64(*batchSize) {
log.Fatal("max keys per second should be bigger than batch size")
}
// Set up instrumentation.
statter := g2s.Noop()
if *statsdAddress != "" {
var err error
statter, err = g2s.Dial("udp", *statsdAddress)
if err != nil {
log.Fatal(err)
}
}
prometheusInstr := prometheus.New(*prometheusNamespace, *prometheusMaxSummaryAge)
prometheusInstr.Install("/metrics", http.DefaultServeMux)
instr := instrumentation.NewMultiInstrumentation(
statsd.New(statter, float32(*statsdSampleRate), *statsdBucketPrefix),
prometheusInstr,
)
// Parse hash function.
var hashFunc func(string) uint32
switch strings.ToLower(*redisHash) {
case "murmur3":
hashFunc = pool.Murmur3
case "fnv":
hashFunc = pool.FNV
case "fnva":
hashFunc = pool.FNVa
default:
log.Fatalf("unknown hash %q", *redisHash)
}
// Set up the clusters.
clusters, err := farm.ParseFarmString(
*redisInstances,
*redisConnectTimeout, *redisReadTimeout, *redisWriteTimeout,
*redisMCPI,
hashFunc,
*maxSize,
*selectGap,
instr,
)
if err != nil {
log.Fatal(err)
}
// HTTP server for profiling.
go func() { log.Print(http.ListenAndServe(*httpAddress, nil)) }()
// Set up our rate limiter. Remember: it's per-key, not per-request.
var (
freq = time.Duration(1/(*maxKeysPerSecond)) * time.Second
bucket = tb.NewBucket(*maxKeysPerSecond, freq)
)
// Build the farm.
var (
readStrategy = farm.SendAllReadAll
repairStrategy = farm.AllRepairs // blocking
writeQuorum = len(clusters) // 100%
dst = farm.New(clusters, writeQuorum, readStrategy, repairStrategy, instr)
)
// Perform the walk.
defer func(t time.Time) { log.Printf("total walk complete, %s", time.Since(t)) }(time.Now())
for {
src := scan(clusters, *batchSize, *scanLogInterval) // new key set
walkOnce(dst, bucket, src, *maxSize, instr)
if *once {
break
}
}
}