Class KafkaIdempotentRepository
- java.lang.Object
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- org.apache.camel.support.service.BaseService
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- org.apache.camel.support.service.ServiceSupport
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- org.apache.camel.processor.idempotent.kafka.KafkaIdempotentRepository
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- All Implemented Interfaces:
AutoCloseable
,org.apache.camel.CamelContextAware
,org.apache.camel.Service
,org.apache.camel.ShutdownableService
,org.apache.camel.spi.IdempotentRepository
,org.apache.camel.StatefulService
,org.apache.camel.SuspendableService
@ManagedResource(description="Kafka IdempotentRepository") public class KafkaIdempotentRepository extends org.apache.camel.support.service.ServiceSupport implements org.apache.camel.spi.IdempotentRepository, org.apache.camel.CamelContextAware
A Kafka topic-based implementation ofIdempotentRepository
. Uses a local cache of previously seen Message IDs. Mutations that come in via the (add(String)
), orremove(String)
method will update the local cache and broadcast the change in state on a Kafka topic to other instances. The cache is back-filled from the topic by a Kafka consumer. The topic used must be unique per logical repository (i.e. two routes de-duplicate using different repositories, and different topics). This class makes no assumptions about the number of partitions (it is designed to consume from all at the same time), or replication factor of the topic. Each repository instance that uses the topic (e.g. typically on different machines running in parallel) controls its own consumer group, so in a cluster of 10 Camel processes using the same topic each will control its own offset. On startup, the instance subscribes to the topic and rewinds the offset to the beginning, rebuilding the cache to the latest state. The cache will not be considered warmed up until one poll ofpollDurationMs
in length returns 0 records. Startup will not be completed until either the cache has warmed up, or 30 seconds go by; if the latter happens the idempotent repository may be in an inconsistent state until its consumer catches up to the end of the topic. To use, this repository must be placed in the Camel registry, either manually or by registration as a bean in Spring/Blueprint, as it is CamelContext aware.
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Constructor Summary
Constructors Constructor Description KafkaIdempotentRepository()
No-op constructor for XML/property-based object initialisation.KafkaIdempotentRepository(String topic, String bootstrapServers)
KafkaIdempotentRepository(String topic, String bootstrapServers, int maxCacheSize, int pollDurationMs)
KafkaIdempotentRepository(String topic, String bootstrapServers, int maxCacheSize, int pollDurationMs, String groupId)
KafkaIdempotentRepository(String topic, String bootstrapServers, String groupId)
KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig)
KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, int maxCacheSize, int pollDurationMs)
KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, int maxCacheSize, int pollDurationMs, String groupId)
KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, String groupId)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(String key)
void
clear()
boolean
confirm(String key)
boolean
contains(String key)
protected void
doStart()
protected void
doStop()
String
getBootstrapServers()
org.apache.camel.CamelContext
getCamelContext()
Properties
getConsumerConfig()
String
getGroupId()
int
getMaxCacheSize()
int
getPollDurationMs()
Properties
getProducerConfig()
String
getTopic()
boolean
isCacheReady()
boolean
isPollerRunning()
boolean
remove(String key)
void
setBootstrapServers(String bootstrapServers)
Sets thevoid
setCamelContext(org.apache.camel.CamelContext camelContext)
void
setConsumerConfig(Properties consumerConfig)
Sets the properties that will be used by the Kafka consumer.void
setGroupId(String groupId)
Sets the group id of the Kafka consumer.void
setMaxCacheSize(int maxCacheSize)
Sets the maximum size of the local key cache.void
setPollDurationMs(int pollDurationMs)
Sets the poll duration of the Kafka consumer.void
setProducerConfig(Properties producerConfig)
Sets the properties that will be used by the Kafka producer.void
setTopic(String topic)
Sets the name of the Kafka topic used by this idempotent repository.-
Methods inherited from class org.apache.camel.support.service.BaseService
build, doBuild, doFail, doInit, doLifecycleChange, doResume, doShutdown, doSuspend, fail, getStatus, init, isBuild, isInit, isNew, isRunAllowed, isShutdown, isStarted, isStarting, isStartingOrStarted, isStopped, isStopping, isStoppingOrStopped, isSuspended, isSuspending, isSuspendingOrSuspended, resume, shutdown, start, stop, suspend
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.apache.camel.spi.IdempotentRepository
add, confirm, contains, remove
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Constructor Detail
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KafkaIdempotentRepository
public KafkaIdempotentRepository()
No-op constructor for XML/property-based object initialisation. From Java, prefer one of the other constructors.
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, String bootstrapServers, String groupId)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, String bootstrapServers, int maxCacheSize, int pollDurationMs)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, String groupId)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, int maxCacheSize, int pollDurationMs)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, String bootstrapServers, int maxCacheSize, int pollDurationMs, String groupId)
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KafkaIdempotentRepository
public KafkaIdempotentRepository(String topic, Properties consumerConfig, Properties producerConfig, int maxCacheSize, int pollDurationMs, String groupId)
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Method Detail
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getTopic
public String getTopic()
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setTopic
public void setTopic(String topic)
Sets the name of the Kafka topic used by this idempotent repository. Each functionally-separate repository should use a different topic.- Parameters:
topic
- The topic name.
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getBootstrapServers
public String getBootstrapServers()
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setBootstrapServers
public void setBootstrapServers(String bootstrapServers)
Sets thebootstrap.servers
property on the internal Kafka producer and consumer. Use this as shorthand if not settingconsumerConfig
andproducerConfig
. If used, this component will apply sensible default configurations for the producer and consumer.- Parameters:
bootstrapServers
- Thebootstrap.servers
value to use.
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getProducerConfig
public Properties getProducerConfig()
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setProducerConfig
public void setProducerConfig(Properties producerConfig)
Sets the properties that will be used by the Kafka producer. OverridesbootstrapServers
, so must define thebootstrap.servers
property itself. Prefer usingbootstrapServers
for default configuration unless you specifically need non-standard configuration options such as SSL/SASL.- Parameters:
producerConfig
- The producer configuration properties.
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getConsumerConfig
public Properties getConsumerConfig()
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setConsumerConfig
public void setConsumerConfig(Properties consumerConfig)
Sets the properties that will be used by the Kafka consumer. OverridesbootstrapServers
, so must define thebootstrap.servers
property itself. Prefer usingbootstrapServers
for default configuration unless you specifically need non-standard configuration options such as SSL/SASL.- Parameters:
consumerConfig
- The consumer configuration properties.
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getMaxCacheSize
public int getMaxCacheSize()
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setMaxCacheSize
public void setMaxCacheSize(int maxCacheSize)
Sets the maximum size of the local key cache.- Parameters:
maxCacheSize
- The maximum key cache size.
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getPollDurationMs
public int getPollDurationMs()
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setPollDurationMs
public void setPollDurationMs(int pollDurationMs)
Sets the poll duration of the Kafka consumer. The local caches are updated immediately; this value will affect how far behind other peers in the cluster are, which are updating their caches from the topic, relative to the idempotent consumer instance issued the cache action message. The default value of this isDEFAULT_POLL_DURATION_MS
. If setting this value explicitly, be aware that there is a tradeoff between the remote cache liveness and the volume of network traffic between this repository's consumer and the Kafka brokers. The cache warmup process also depends on there being one poll that fetches nothing - this indicates that the stream has been consumed up to the current point. If the poll duration is excessively long for the rate at which messages are sent on the topic, there exists a possibility that the cache cannot be warmed up and will operate in an inconsistent state relative to its peers until it catches up.- Parameters:
pollDurationMs
- The poll duration in milliseconds.
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getGroupId
public String getGroupId()
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setGroupId
public void setGroupId(String groupId)
Sets the group id of the Kafka consumer.- Parameters:
groupId
- The poll duration in milliseconds.
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setCamelContext
public void setCamelContext(org.apache.camel.CamelContext camelContext)
- Specified by:
setCamelContext
in interfaceorg.apache.camel.CamelContextAware
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getCamelContext
public org.apache.camel.CamelContext getCamelContext()
- Specified by:
getCamelContext
in interfaceorg.apache.camel.CamelContextAware
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doStart
protected void doStart() throws Exception
- Overrides:
doStart
in classorg.apache.camel.support.service.BaseService
- Throws:
Exception
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doStop
protected void doStop()
- Overrides:
doStop
in classorg.apache.camel.support.service.BaseService
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add
public boolean add(String key)
- Specified by:
add
in interfaceorg.apache.camel.spi.IdempotentRepository
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contains
@ManagedOperation(description="Does the store contain the given key") public boolean contains(String key)
- Specified by:
contains
in interfaceorg.apache.camel.spi.IdempotentRepository
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remove
@ManagedOperation(description="Remove the key from the store") public boolean remove(String key)
- Specified by:
remove
in interfaceorg.apache.camel.spi.IdempotentRepository
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confirm
public boolean confirm(String key)
- Specified by:
confirm
in interfaceorg.apache.camel.spi.IdempotentRepository
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clear
public void clear()
- Specified by:
clear
in interfaceorg.apache.camel.spi.IdempotentRepository
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isPollerRunning
@ManagedOperation(description="Number of times duplicate messages have been detected") public boolean isPollerRunning()
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isCacheReady
public boolean isCacheReady()
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