package sarama import ( "crypto/tls" "regexp" "time" ) const defaultClientID = "sarama" var validID = regexp.MustCompile(`\A[A-Za-z0-9._-]+\z`) // Config is used to pass multiple configuration options to Sarama's constructors. type Config struct { // Net is the namespace for network-level properties used by the Broker, and // shared by the Client/Producer/Consumer. Net struct { // How many outstanding requests a connection is allowed to have before // sending on it blocks (default 5). MaxOpenRequests int // All three of the below configurations are similar to the // `socket.timeout.ms` setting in JVM kafka. All of them default // to 30 seconds. DialTimeout time.Duration // How long to wait for the initial connection. ReadTimeout time.Duration // How long to wait for a response. WriteTimeout time.Duration // How long to wait for a transmit. TLS struct { // Whether or not to use TLS when connecting to the broker // (defaults to false). Enable bool // The TLS configuration to use for secure connections if // enabled (defaults to nil). Config *tls.Config } // SASL based authentication with broker. While there are multiple SASL authentication methods // the current implementation is limited to plaintext (SASL/PLAIN) authentication SASL struct { // Whether or not to use SASL authentication when connecting to the broker // (defaults to false). Enable bool //username and password for SASL/PLAIN authentication User string Password string } // KeepAlive specifies the keep-alive period for an active network connection. // If zero, keep-alives are disabled. (default is 0: disabled). KeepAlive time.Duration } // Metadata is the namespace for metadata management properties used by the // Client, and shared by the Producer/Consumer. Metadata struct { Retry struct { // The total number of times to retry a metadata request when the // cluster is in the middle of a leader election (default 3). Max int // How long to wait for leader election to occur before retrying // (default 250ms). Similar to the JVM's `retry.backoff.ms`. Backoff time.Duration } // How frequently to refresh the cluster metadata in the background. // Defaults to 10 minutes. Set to 0 to disable. Similar to // `topic.metadata.refresh.interval.ms` in the JVM version. RefreshFrequency time.Duration } // Producer is the namespace for configuration related to producing messages, // used by the Producer. Producer struct { // The maximum permitted size of a message (defaults to 1000000). Should be // set equal to or smaller than the broker's `message.max.bytes`. MaxMessageBytes int // The level of acknowledgement reliability needed from the broker (defaults // to WaitForLocal). Equivalent to the `request.required.acks` setting of the // JVM producer. RequiredAcks RequiredAcks // The maximum duration the broker will wait the receipt of the number of // RequiredAcks (defaults to 10 seconds). This is only relevant when // RequiredAcks is set to WaitForAll or a number > 1. Only supports // millisecond resolution, nanoseconds will be truncated. Equivalent to // the JVM producer's `request.timeout.ms` setting. Timeout time.Duration // The type of compression to use on messages (defaults to no compression). // Similar to `compression.codec` setting of the JVM producer. Compression CompressionCodec // Generates partitioners for choosing the partition to send messages to // (defaults to hashing the message key). Similar to the `partitioner.class` // setting for the JVM producer. Partitioner PartitionerConstructor // Return specifies what channels will be populated. If they are set to true, // you must read from the respective channels to prevent deadlock. Return struct { // If enabled, successfully delivered messages will be returned on the // Successes channel (default disabled). Successes bool // If enabled, messages that failed to deliver will be returned on the // Errors channel, including error (default enabled). Errors bool } // The following config options control how often messages are batched up and // sent to the broker. By default, messages are sent as fast as possible, and // all messages received while the current batch is in-flight are placed // into the subsequent batch. Flush struct { // The best-effort number of bytes needed to trigger a flush. Use the // global sarama.MaxRequestSize to set a hard upper limit. Bytes int // The best-effort number of messages needed to trigger a flush. Use // `MaxMessages` to set a hard upper limit. Messages int // The best-effort frequency of flushes. Equivalent to // `queue.buffering.max.ms` setting of JVM producer. Frequency time.Duration // The maximum number of messages the producer will send in a single // broker request. Defaults to 0 for unlimited. Similar to // `queue.buffering.max.messages` in the JVM producer. MaxMessages int } Retry struct { // The total number of times to retry sending a message (default 3). // Similar to the `message.send.max.retries` setting of the JVM producer. Max int // How long to wait for the cluster to settle between retries // (default 100ms). Similar to the `retry.backoff.ms` setting of the // JVM producer. Backoff time.Duration } } // Consumer is the namespace for configuration related to consuming messages, // used by the Consumer. // // Note that Sarama's Consumer type does not currently support automatic // consumer-group rebalancing and offset tracking. For Zookeeper-based // tracking (Kafka 0.8.2 and earlier), the https://github.com/wvanbergen/kafka // library builds on Sarama to add this support. For Kafka-based tracking // (Kafka 0.9 and later), the https://github.com/bsm/sarama-cluster library // builds on Sarama to add this support. Consumer struct { Retry struct { // How long to wait after a failing to read from a partition before // trying again (default 2s). Backoff time.Duration } // Fetch is the namespace for controlling how many bytes are retrieved by any // given request. Fetch struct { // The minimum number of message bytes to fetch in a request - the broker // will wait until at least this many are available. The default is 1, // as 0 causes the consumer to spin when no messages are available. // Equivalent to the JVM's `fetch.min.bytes`. Min int32 // The default number of message bytes to fetch from the broker in each // request (default 32768). This should be larger than the majority of // your messages, or else the consumer will spend a lot of time // negotiating sizes and not actually consuming. Similar to the JVM's // `fetch.message.max.bytes`. Default int32 // The maximum number of message bytes to fetch from the broker in a // single request. Messages larger than this will return // ErrMessageTooLarge and will not be consumable, so you must be sure // this is at least as large as your largest message. Defaults to 0 // (no limit). Similar to the JVM's `fetch.message.max.bytes`. The // global `sarama.MaxResponseSize` still applies. Max int32 } // The maximum amount of time the broker will wait for Consumer.Fetch.Min // bytes to become available before it returns fewer than that anyways. The // default is 250ms, since 0 causes the consumer to spin when no events are // available. 100-500ms is a reasonable range for most cases. Kafka only // supports precision up to milliseconds; nanoseconds will be truncated. // Equivalent to the JVM's `fetch.wait.max.ms`. MaxWaitTime time.Duration // The maximum amount of time the consumer expects a message takes to process // for the user. If writing to the Messages channel takes longer than this, // that partition will stop fetching more messages until it can proceed again. // Note that, since the Messages channel is buffered, the actual grace time is // (MaxProcessingTime * ChanneBufferSize). Defaults to 100ms. MaxProcessingTime time.Duration // Return specifies what channels will be populated. If they are set to true, // you must read from them to prevent deadlock. Return struct { // If enabled, any errors that occurred while consuming are returned on // the Errors channel (default disabled). Errors bool } // Offsets specifies configuration for how and when to commit consumed // offsets. This currently requires the manual use of an OffsetManager // but will eventually be automated. Offsets struct { // How frequently to commit updated offsets. Defaults to 1s. CommitInterval time.Duration // The initial offset to use if no offset was previously committed. // Should be OffsetNewest or OffsetOldest. Defaults to OffsetNewest. Initial int64 // The retention duration for committed offsets. If zero, disabled // (in which case the `offsets.retention.minutes` option on the // broker will be used). Kafka only supports precision up to // milliseconds; nanoseconds will be truncated. Requires Kafka // broker version 0.9.0 or later. // (default is 0: disabled). Retention time.Duration } } // A user-provided string sent with every request to the brokers for logging, // debugging, and auditing purposes. Defaults to "sarama", but you should // probably set it to something specific to your application. ClientID string // The number of events to buffer in internal and external channels. This // permits the producer and consumer to continue processing some messages // in the background while user code is working, greatly improving throughput. // Defaults to 256. ChannelBufferSize int // The version of Kafka that Sarama will assume it is running against. // Defaults to the oldest supported stable version. Since Kafka provides // backwards-compatibility, setting it to a version older than you have // will not break anything, although it may prevent you from using the // latest features. Setting it to a version greater than you are actually // running may lead to random breakage. Version KafkaVersion } // NewConfig returns a new configuration instance with sane defaults. func NewConfig() *Config { c := &Config{} c.Net.MaxOpenRequests = 5 c.Net.DialTimeout = 30 * time.Second c.Net.ReadTimeout = 30 * time.Second c.Net.WriteTimeout = 30 * time.Second c.Metadata.Retry.Max = 3 c.Metadata.Retry.Backoff = 250 * time.Millisecond c.Metadata.RefreshFrequency = 10 * time.Minute c.Producer.MaxMessageBytes = 1000000 c.Producer.RequiredAcks = WaitForLocal c.Producer.Timeout = 10 * time.Second c.Producer.Partitioner = NewHashPartitioner c.Producer.Retry.Max = 3 c.Producer.Retry.Backoff = 100 * time.Millisecond c.Producer.Return.Errors = true c.Consumer.Fetch.Min = 1 c.Consumer.Fetch.Default = 32768 c.Consumer.Retry.Backoff = 2 * time.Second c.Consumer.MaxWaitTime = 250 * time.Millisecond c.Consumer.MaxProcessingTime = 100 * time.Millisecond c.Consumer.Return.Errors = false c.Consumer.Offsets.CommitInterval = 1 * time.Second c.Consumer.Offsets.Initial = OffsetNewest c.ClientID = defaultClientID c.ChannelBufferSize = 256 c.Version = minVersion return c } // Validate checks a Config instance. It will return a // ConfigurationError if the specified values don't make sense. func (c *Config) Validate() error { // some configuration values should be warned on but not fail completely, do those first if c.Net.TLS.Enable == false && c.Net.TLS.Config != nil { Logger.Println("Net.TLS is disabled but a non-nil configuration was provided.") } if c.Net.SASL.Enable == false { if c.Net.SASL.User != "" { Logger.Println("Net.SASL is disabled but a non-empty username was provided.") } if c.Net.SASL.Password != "" { Logger.Println("Net.SASL is disabled but a non-empty password was provided.") } } if c.Producer.RequiredAcks > 1 { Logger.Println("Producer.RequiredAcks > 1 is deprecated and will raise an exception with kafka >= 0.8.2.0.") } if c.Producer.MaxMessageBytes >= int(MaxRequestSize) { Logger.Println("Producer.MaxMessageBytes is larger than MaxRequestSize; it will be ignored.") } if c.Producer.Flush.Bytes >= int(MaxRequestSize) { Logger.Println("Producer.Flush.Bytes is larger than MaxRequestSize; it will be ignored.") } if c.Producer.Timeout%time.Millisecond != 0 { Logger.Println("Producer.Timeout only supports millisecond resolution; nanoseconds will be truncated.") } if c.Consumer.MaxWaitTime < 100*time.Millisecond { Logger.Println("Consumer.MaxWaitTime is very low, which can cause high CPU and network usage. See documentation for details.") } if c.Consumer.MaxWaitTime%time.Millisecond != 0 { Logger.Println("Consumer.MaxWaitTime only supports millisecond precision; nanoseconds will be truncated.") } if c.Consumer.Offsets.Retention%time.Millisecond != 0 { Logger.Println("Consumer.Offsets.Retention only supports millisecond precision; nanoseconds will be truncated.") } if c.ClientID == defaultClientID { Logger.Println("ClientID is the default of 'sarama', you should consider setting it to something application-specific.") } // validate Net values switch { case c.Net.MaxOpenRequests <= 0: return ConfigurationError("Net.MaxOpenRequests must be > 0") case c.Net.DialTimeout <= 0: return ConfigurationError("Net.DialTimeout must be > 0") case c.Net.ReadTimeout <= 0: return ConfigurationError("Net.ReadTimeout must be > 0") case c.Net.WriteTimeout <= 0: return ConfigurationError("Net.WriteTimeout must be > 0") case c.Net.KeepAlive < 0: return ConfigurationError("Net.KeepAlive must be >= 0") case c.Net.SASL.Enable == true && c.Net.SASL.User == "": return ConfigurationError("Net.SASL.User must not be empty when SASL is enabled") case c.Net.SASL.Enable == true && c.Net.SASL.Password == "": return ConfigurationError("Net.SASL.Password must not be empty when SASL is enabled") } // validate the Metadata values switch { case c.Metadata.Retry.Max < 0: return ConfigurationError("Metadata.Retry.Max must be >= 0") case c.Metadata.Retry.Backoff < 0: return ConfigurationError("Metadata.Retry.Backoff must be >= 0") case c.Metadata.RefreshFrequency < 0: return ConfigurationError("Metadata.RefreshFrequency must be >= 0") } // validate the Producer values switch { case c.Producer.MaxMessageBytes <= 0: return ConfigurationError("Producer.MaxMessageBytes must be > 0") case c.Producer.RequiredAcks < -1: return ConfigurationError("Producer.RequiredAcks must be >= -1") case c.Producer.Timeout <= 0: return ConfigurationError("Producer.Timeout must be > 0") case c.Producer.Partitioner == nil: return ConfigurationError("Producer.Partitioner must not be nil") case c.Producer.Flush.Bytes < 0: return ConfigurationError("Producer.Flush.Bytes must be >= 0") case c.Producer.Flush.Messages < 0: return ConfigurationError("Producer.Flush.Messages must be >= 0") case c.Producer.Flush.Frequency < 0: return ConfigurationError("Producer.Flush.Frequency must be >= 0") case c.Producer.Flush.MaxMessages < 0: return ConfigurationError("Producer.Flush.MaxMessages must be >= 0") case c.Producer.Flush.MaxMessages > 0 && c.Producer.Flush.MaxMessages < c.Producer.Flush.Messages: return ConfigurationError("Producer.Flush.MaxMessages must be >= Producer.Flush.Messages when set") case c.Producer.Retry.Max < 0: return ConfigurationError("Producer.Retry.Max must be >= 0") case c.Producer.Retry.Backoff < 0: return ConfigurationError("Producer.Retry.Backoff must be >= 0") } // validate the Consumer values switch { case c.Consumer.Fetch.Min <= 0: return ConfigurationError("Consumer.Fetch.Min must be > 0") case c.Consumer.Fetch.Default <= 0: return ConfigurationError("Consumer.Fetch.Default must be > 0") case c.Consumer.Fetch.Max < 0: return ConfigurationError("Consumer.Fetch.Max must be >= 0") case c.Consumer.MaxWaitTime < 1*time.Millisecond: return ConfigurationError("Consumer.MaxWaitTime must be >= 1ms") case c.Consumer.MaxProcessingTime <= 0: return ConfigurationError("Consumer.MaxProcessingTime must be > 0") case c.Consumer.Retry.Backoff < 0: return ConfigurationError("Consumer.Retry.Backoff must be >= 0") case c.Consumer.Offsets.CommitInterval <= 0: return ConfigurationError("Consumer.Offsets.CommitInterval must be > 0") case c.Consumer.Offsets.Initial != OffsetOldest && c.Consumer.Offsets.Initial != OffsetNewest: return ConfigurationError("Consumer.Offsets.Initial must be OffsetOldest or OffsetNewest") } // validate misc shared values switch { case c.ChannelBufferSize < 0: return ConfigurationError("ChannelBufferSize must be >= 0") case !validID.MatchString(c.ClientID): return ConfigurationError("ClientID is invalid") } return nil }