屬性

默認(rèn)值

描述

broker.id

必填參數(shù)，broker的唯一標(biāo)識(shí)

log.dirs

/tmp/kafka-logs

Kafka數(shù)據(jù)存放的目錄。可以指定多個(gè)目錄，中間用逗號(hào)分隔，當(dāng)新partition被創(chuàng)建的時(shí)會(huì)被存放到當(dāng)前存放partition最少的目錄。

port

9092

BrokerServer接受客戶端連接的端口號(hào)

zookeeper.connect

null

Zookeeper的連接串，格式為：hostname1:port1,hostname2:port2,hostname3:port3。可以填一個(gè)或多個(gè)，為了提高可靠性，建議都填上。注意，此配置允許我們指定一個(gè)zookeeper路徑來(lái)存放此kafka集群的所有數(shù)據(jù)，為了與其他應(yīng)用集群區(qū)分開，建議在此配置中指定本集群存放目錄，格式為：hostname1:port1,hostname2:port2,hostname3:port3/chroot/path 。需要注意的是，消費(fèi)者的參數(shù)要和此參數(shù)一致。

message.max.bytes

1000000

服務(wù)器可以接收到的最大的消息大小。注意此參數(shù)要和consumer的maximum.message.size大小一致，否則會(huì)因?yàn)樯a(chǎn)者生產(chǎn)的消息太大導(dǎo)致消費(fèi)者無(wú)法消費(fèi)。

num.io.threads

8

服務(wù)器用來(lái)執(zhí)行讀寫請(qǐng)求的IO線程數(shù)，此參數(shù)的數(shù)量至少要等于服務(wù)器上磁盤的數(shù)量。

queued.max.requests

500

I/O線程可以處理請(qǐng)求的隊(duì)列大小，若實(shí)際請(qǐng)求數(shù)超過(guò)此大小，網(wǎng)絡(luò)線程將停止接收新的請(qǐng)求。

socket.send.buffer.bytes

100 * 1024

The SO_SNDBUFF buffer the server prefers for socket connections.

socket.receive.buffer.bytes

100 * 1024

The SO_RCVBUFF buffer the server prefers for socket connections.

socket.request.max.bytes

100 * 1024 * 1024

服務(wù)器允許請(qǐng)求的最大值， 用來(lái)防止內(nèi)存溢出，其值應(yīng)該小于 Java heap size.

num.partitions

1

默認(rèn)partition數(shù)量，如果topic在創(chuàng)建時(shí)沒(méi)有指定partition數(shù)量，默認(rèn)使用此值，建議改為5

log.segment.bytes

1024 * 1024 * 1024

Segment文件的大小，超過(guò)此值將會(huì)自動(dòng)新建一個(gè)segment，此值可以被topic級(jí)別的參數(shù)覆蓋。

log.roll.{ms,hours}

24 * 7 hours

新建segment文件的時(shí)間，此值可以被topic級(jí)別的參數(shù)覆蓋。

log.retention.{ms,minutes,hours}

7 days

Kafka segment log的保存周期，保存周期超過(guò)此時(shí)間日志就會(huì)被刪除。此參數(shù)可以被topic級(jí)別參數(shù)覆蓋。數(shù)據(jù)量大時(shí)，建議減小此值。

log.retention.bytes

-1

每個(gè)partition的最大容量，若數(shù)據(jù)量超過(guò)此值，partition數(shù)據(jù)將會(huì)被刪除。注意這個(gè)參數(shù)控制的是每個(gè)partition而不是topic。此參數(shù)可以被log級(jí)別參數(shù)覆蓋。

log.retention.check.interval.ms

5 minutes

刪除策略的檢查周期

auto.create.topics.enable

true

自動(dòng)創(chuàng)建topic參數(shù)，建議此值設(shè)置為false，嚴(yán)格控制topic管理，防止生產(chǎn)者錯(cuò)寫topic。

default.replication.factor

1

默認(rèn)副本數(shù)量，建議改為2。

replica.lag.time.max.ms

10000

在此窗口時(shí)間內(nèi)沒(méi)有收到follower的fetch請(qǐng)求，leader會(huì)將其從ISR(in-sync replicas)中移除。

replica.lag.max.messages

4000

如果replica節(jié)點(diǎn)落后leader節(jié)點(diǎn)此值大小的消息數(shù)量，leader節(jié)點(diǎn)就會(huì)將其從ISR中移除。

replica.socket.timeout.ms

30 * 1000

replica向leader發(fā)送請(qǐng)求的超時(shí)時(shí)間。

replica.socket.receive.buffer.bytes

64 * 1024

The socket receive buffer for network requests to the leader for replicating data.

replica.fetch.max.bytes

1024 * 1024

The number of byes of messages to attempt to fetch for each partition in the fetch requests the replicas send to the leader.

replica.fetch.wait.max.ms

500

The maximum amount of time to wait time for data to arrive on the leader in the fetch requests sent by the replicas to the leader.

num.replica.fetchers

1

Number of threads used to replicate messages from leaders. Increasing this value can increase the degree of I/O parallelism in the follower broker.

fetch.purgatory.purge.interval.requests

1000

The purge interval (in number of requests) of the fetch request purgatory.

zookeeper.session.timeout.ms

6000

ZooKeeper session 超時(shí)時(shí)間。如果在此時(shí)間內(nèi)server沒(méi)有向zookeeper發(fā)送心跳，zookeeper就會(huì)認(rèn)為此節(jié)點(diǎn)已掛掉。 此值太低導(dǎo)致節(jié)點(diǎn)容易被標(biāo)記死亡；若太高，.會(huì)導(dǎo)致太遲發(fā)現(xiàn)節(jié)點(diǎn)死亡。

zookeeper.connection.timeout.ms

6000

客戶端連接zookeeper的超時(shí)時(shí)間。

zookeeper.sync.time.ms

2000

H ZK follower落后 ZK leader的時(shí)間。

controlled.shutdown.enable

true

允許broker shutdown。如果啟用，broker在關(guān)閉自己之前會(huì)把它上面的所有l(wèi)eaders轉(zhuǎn)移到其它brokers上，建議啟用，增加集群穩(wěn)定性。

auto.leader.rebalance.enable

true

If this is enabled the controller will automatically try to balance leadership for partitions among the brokers by periodically returning leadership to the “preferred” replica for each partition if it is available.

leader.imbalance.per.broker.percentage

10

The percentage of leader imbalance allowed per broker. The controller will rebalance leadership if this ratio goes above the configured value per broker.

leader.imbalance.check.interval.seconds

300

The frequency with which to check for leader imbalance.

offset.metadata.max.bytes

4096

The maximum amount of metadata to allow clients to save with their offsets.

connections.max.idle.ms

600000

Idle connections timeout: the server socket processor threads close the connections that idle more than this.

num.recovery.threads.per.data.dir

1

The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.

unclean.leader.election.enable

true

Indicates whether to enable replicas not in the ISR set to be elected as leader as a last resort, even though doing so may result in data loss.

delete.topic.enable

false

啟用deletetopic參數(shù)，建議設(shè)置為true。

offsets.topic.num.partitions

50

The number of partitions for the offset commit topic. Since changing this after deployment is currently unsupported, we recommend using a higher setting for production (e.g., 100-200).

offsets.topic.retention.minutes

1440

Offsets that are older than this age will be marked for deletion. The actual purge will occur when the log cleaner compacts the offsets topic.

offsets.retention.check.interval.ms

600000

The frequency at which the offset manager checks for stale offsets.

offsets.topic.replication.factor

3

The replication factor for the offset commit topic. A higher setting (e.g., three or four) is recommended in order to ensure higher availability. If the offsets topic is created when fewer brokers than the replication factor then the offsets topic will be created with fewer replicas.

offsets.topic.segment.bytes

104857600

Segment size for the offsets topic. Since it uses a compacted topic, this should be kept relatively low in order to facilitate faster log compaction and loads.

offsets.load.buffer.size

5242880

An offset load occurs when a broker becomes the offset manager for a set of consumer groups (i.e., when it becomes a leader for an offsets topic partition). This setting corresponds to the batch size (in bytes) to use when reading from the offsets segments when loading offsets into the offset manager’s cache.

offsets.commit.required.acks

-1

The number of acknowledgements that are required before the offset commit can be accepted. This is similar to the producer’s acknowledgement setting. In general, the default should not be overridden.

offsets.commit.timeout.ms

5000

The offset commit will be delayed until this timeout or the required number of replicas have received the offset commit. This is similar to the producer request timeout.

屬性

默認(rèn)值

描述

metadata.broker.list

啟動(dòng)時(shí)producer查詢brokers的列表，可以是集群中所有brokers的一個(gè)子集。注意，這個(gè)參數(shù)只是用來(lái)獲取topic的元信息用，producer會(huì)從元信息中挑選合適的broker并與之建立socket連接。格式是：host1:port1,host2:port2。

request.required.acks

0

參見(jiàn)3.2節(jié)介紹

request.timeout.ms

10000

Broker等待ack的超時(shí)時(shí)間，若等待時(shí)間超過(guò)此值，會(huì)返回客戶端錯(cuò)誤信息。

producer.type

sync

同步異步模式。async表示異步，sync表示同步。如果設(shè)置成異步模式，可以允許生產(chǎn)者以batch的形式push數(shù)據(jù)，這樣會(huì)極大的提高broker性能，推薦設(shè)置為異步。

serializer.class

kafka.serializer.DefaultEncoder

序列號(hào)類，.默認(rèn)序列化成 byte[] 。

key.serializer.class

Key的序列化類，默認(rèn)同上。

partitioner.class

kafka.producer.DefaultPartitioner

Partition類，默認(rèn)對(duì)key進(jìn)行hash。

compression.codec

none

指定producer消息的壓縮格式，可選參數(shù)為： “none”, “gzip” and “snappy”。關(guān)于壓縮參見(jiàn)4.1節(jié)

compressed.topics

null

啟用壓縮的topic名稱。若上面參數(shù)選擇了一個(gè)壓縮格式，那么壓縮僅對(duì)本參數(shù)指定的topic有效，若本參數(shù)為空，則對(duì)所有topic有效。

message.send.max.retries

3

Producer發(fā)送失敗時(shí)重試次數(shù)。若網(wǎng)絡(luò)出現(xiàn)問(wèn)題，可能會(huì)導(dǎo)致不斷重試。

retry.backoff.ms

100

Before each retry, the producer refreshes the metadata of relevant topics to see if a new leader has been elected. Since leader election takes a bit of time, this property specifies the amount of time that the producer waits before refreshing the metadata.

topic.metadata.refresh.interval.ms

600 * 1000

The producer generally refreshes the topic metadata from brokers when there is a failure (partition missing, leader not available…). It will also poll regularly (default: every 10min so 600000ms). If you set this to a negative value, metadata will only get refreshed on failure. If you set this to zero, the metadata will get refreshed after each message sent (not recommended). Important note: the refresh happen only AFTER the message is sent, so if the producer never sends a message the metadata is never refreshed

queue.buffering.max.ms

5000

啟用異步模式時(shí)，producer緩存消息的時(shí)間。比如我們?cè)O(shè)置成1000時(shí)，它會(huì)緩存1秒的數(shù)據(jù)再一次發(fā)送出去，這樣可以極大的增加broker吞吐量，但也會(huì)造成時(shí)效性的降低。

queue.buffering.max.messages

10000

采用異步模式時(shí)producer buffer 隊(duì)列里最大緩存的消息數(shù)量，如果超過(guò)這個(gè)數(shù)值，producer就會(huì)阻塞或者丟掉消息。

queue.enqueue.timeout.ms

-1

當(dāng)達(dá)到上面參數(shù)值時(shí)producer阻塞等待的時(shí)間。如果值設(shè)置為0，buffer隊(duì)列滿時(shí)producer不會(huì)阻塞，消息直接被丟掉。若值設(shè)置為-1，producer會(huì)被阻塞，不會(huì)丟消息。

batch.num.messages

200

采用異步模式時(shí)，一個(gè)batch緩存的消息數(shù)量。達(dá)到這個(gè)數(shù)量值時(shí)producer才會(huì)發(fā)送消息。

send.buffer.bytes

100 * 1024

Socket write buffer size

client.id

“”

The client id is a user-specified string sent in each request to help trace calls. It should logically identify the application making the request.

屬性

默認(rèn)值

描述

group.id

Consumer的組ID，相同goup.id的consumer屬于同一個(gè)組。

zookeeper.connect

Consumer的zookeeper連接串，要和broker的配置一致。

consumer.id

null

如果不設(shè)置會(huì)自動(dòng)生成。

socket.timeout.ms

30 * 1000

網(wǎng)絡(luò)請(qǐng)求的socket超時(shí)時(shí)間。實(shí)際超時(shí)時(shí)間由max.fetch.wait + socket.timeout.ms 確定。

socket.receive.buffer.bytes

64 * 1024

The socket receive buffer for network requests.

fetch.message.max.bytes

1024 * 1024

查詢topic-partition時(shí)允許的最大消息大小。consumer會(huì)為每個(gè)partition緩存此大小的消息到內(nèi)存，因此，這個(gè)參數(shù)可以控制consumer的內(nèi)存使用量。這個(gè)值應(yīng)該至少比server允許的最大消息大小大，以免producer發(fā)送的消息大于consumer允許的消息。

num.consumer.fetchers

1

The number fetcher threads used to fetch data.

auto.commit.enable

true

如果此值設(shè)置為true，consumer會(huì)周期性的把當(dāng)前消費(fèi)的offset值保存到zookeeper。當(dāng)consumer失敗重啟之后將會(huì)使用此值作為新開始消費(fèi)的值。

auto.commit.interval.ms

60 * 1000

Consumer提交offset值到zookeeper的周期。

queued.max.message.chunks

2

用來(lái)被consumer消費(fèi)的message chunks 數(shù)量， 每個(gè)chunk可以緩存fetch.message.max.bytes大小的數(shù)據(jù)量。

auto.commit.interval.ms

60 * 1000

Consumer提交offset值到zookeeper的周期。

queued.max.message.chunks

2

用來(lái)被consumer消費(fèi)的message chunks 數(shù)量， 每個(gè)chunk可以緩存fetch.message.max.bytes大小的數(shù)據(jù)量。

fetch.min.bytes

1

The minimum amount of data the server should return for a fetch request. If insufficient data is available the request will wait for that much data to accumulate before answering the request.

fetch.wait.max.ms

100

The maximum amount of time the server will block before answering the fetch request if there isn’t sufficient data to immediately satisfy fetch.min.bytes.

rebalance.backoff.ms

2000

Backoff time between retries during rebalance.

refresh.leader.backoff.ms

200

Backoff time to wait before trying to determine the leader of a partition that has just lost its leader.

auto.offset.reset

largest

What to do when there is no initial offset in ZooKeeper or if an offset is out of range ;smallest : automatically reset the offset to the smallest offset; largest : automatically reset the offset to the largest offset;anything else: throw exception to the consumer

consumer.timeout.ms

-1

若在指定時(shí)間內(nèi)沒(méi)有消息消費(fèi)，consumer將會(huì)拋出異常。

exclude.internal.topics

true

Whether messages from internal topics (such as offsets) should be exposed to the consumer.

zookeeper.session.timeout.ms

6000

ZooKeeper session timeout. If the consumer fails to heartbeat to ZooKeeper for this period of time it is considered dead and a rebalance will occur.

zookeeper.connection.timeout.ms

6000

The max time that the client waits while establishing a connection to zookeeper.

zookeeper.sync.time.ms

2000

How far a ZK follower can be behind a ZK leader