kafka

Documentation

Index

• Constants
• type ConnTuple
• type EbpfTx
• type KafkaResponseContext
• type KafkaTransaction
• type KafkaTransactionKey
• type Key
• type RawKernelTelemetry
• type RequestStat
• type RequestStats
  • func NewRequestStats() *RequestStats
  • func (r *RequestStats) AddRequest(errorCode int32, count int, staticTags uint64, latency float64)
  • func (r *RequestStats) CombineWith(newStats *RequestStats)

Constants

const (
	// ProduceAPIKey is the API key for produce requests
	ProduceAPIKey = 0

	// FetchAPIKey is the API key for fetch requests
	FetchAPIKey = 1

	// RelativeAccuracy defines the acceptable error in quantile values calculated by DDSketch.
	// For example, if the actual value at p50 is 100, with a relative accuracy of 0.01 the value calculated
	// will be between 99 and 101
	RelativeAccuracy = 0.01
)

const (
	TopicNameBuckets = 0xa
	TopicNameMaxSize = 0x50
)

Types

type ConnTuple

type ConnTuple struct {
	Saddr_h  uint64
	Saddr_l  uint64
	Daddr_h  uint64
	Daddr_l  uint64
	Sport    uint16
	Dport    uint16
	Netns    uint32
	Pid      uint32
	Metadata uint32
}

type EbpfTx

type EbpfTx struct {
	Tup         ConnTuple
	Transaction KafkaTransaction
}

type KafkaResponseContext

type KafkaResponseContext struct {
	Transaction                 KafkaTransaction
	State                       uint8
	Remainder                   uint8
	Varint_position             uint8
	Partition_error_code        int8
	Partition_state             uint8
	Remainder_buf               [4]int8
	Record_batches_num_bytes    int32
	Record_batch_length         int32
	Expected_tcp_seq            uint32
	Carry_over_offset           int32
	Partitions_count            uint32
	Varint_value                uint32
	Record_batches_arrays_idx   uint32
	Record_batches_arrays_count uint32
	Pad_cgo_0                   [4]byte
}

type KafkaTransaction

type KafkaTransaction struct {
	Request_started     uint64
	Response_last_seen  uint64
	Records_count       uint32
	Request_api_key     uint8
	Request_api_version uint8
	Topic_name_size     uint8
	Tags                uint8
	Topic_name          [80]byte
	Error_code          int8
	Pad_cgo_0           [7]byte
}

type KafkaTransactionKey

type KafkaTransactionKey struct {
	Tuple     ConnTuple
	Id        int32
	Pad_cgo_0 [4]byte
}

type Key

type Key struct {
	RequestAPIKey  uint16
	RequestVersion uint16
	TopicName      *intern.StringValue
	types.ConnectionKey
}

Key is an identifier for a group of Kafka transactions

type RawKernelTelemetry

type RawKernelTelemetry struct {
	Topic_name_size_buckets  [10]uint64
	Produce_no_required_acks uint64
}

type RequestStat

type RequestStat struct {
	// this field order is intentional to help the GC pointer tracking
	Latencies *ddsketch.DDSketch
	// Note: every time we add a latency value to the DDSketch, it's possible for the sketch to discard that value
	// (ie if it is outside the range that is tracked by the sketch). For that reason, in order to keep an accurate count
	// the number of kafka transactions processed, we have our own count field (rather than relying on DDSketch.GetCount())
	Count int
	// This field holds the value (in nanoseconds) of the first HTTP request
	// in this bucket. We do this as optimization to avoid creating sketches with
	// a single value. This is quite common in the context of HTTP requests without
	// keep-alives where a short-lived TCP connection is used for a single request.
	FirstLatencySample float64
	StaticTags         uint64
}

RequestStat stores stats for Kafka requests to a particular key

type RequestStats

type RequestStats struct {
	// Go uses optimized map access implementations if the key is int32/int64, so using int32 instead of int8
	// Here you can find the original CPU impact when using int8:
	// https://dd.datad0g.com/dashboard/s3s-3hu-mh6/usm-performance-evaluation-20?fromUser=true&refresh_mode=paused&tpl_var_base_agent-env%5B0%5D=kafka-error-base&tpl_var_client-service%5B0%5D=kafka-client-%2A&tpl_var_compare_agent-env%5B0%5D=kafka-error-new&tpl_var_kube_cluster_name%5B0%5D=usm-datad0g&tpl_var_server-service%5B0%5D=kafka-broker&view=spans&from_ts=1719153394917&to_ts=1719156854000&live=false
	ErrorCodeToStat map[int32]*RequestStat
}

RequestStats stores Kafka request statistics per Kafka error code We include the error code here and not in the Key to avoid creating a new Key for each error code

func NewRequestStats

func NewRequestStats() *RequestStats

NewRequestStats creates a new RequestStats object.

func (*RequestStats) AddRequest

func (r *RequestStats) AddRequest(errorCode int32, count int, staticTags uint64, latency float64)

AddRequest takes information about a Kafka transaction and adds it to the request stats

func (*RequestStats) CombineWith

func (r *RequestStats) CombineWith(newStats *RequestStats)

CombineWith merges the data in 2 RequestStats objects newStats is kept as it is, while the method receiver gets mutated