Consumer (dxldatabusclient 2.4.5 API)

java.lang.Object
- com.opendxl.databus.consumer.Consumer<P>

Type Parameters:

P - payload's type

Direct Known Subclasses:

DatabusConsumer
```
public abstract class Consumer<P>
extends java.lang.Object
```
A abstract consumer, responsible for handling Databus incoming messages. *

Constructor Summary

Constructors
Constructor and Description

Consumer()

Constructors
Constructor and Description
`Consumer()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`assign(java.util.List<TopicPartition> partitions)` Manually assign a list of partition to this consumer.
`java.util.Set<TopicPartition>`	`assignment()` Get the set of topicPartitions currently assigned to this consumer.
`java.util.Map<TopicPartition,java.lang.Long>`	`beginningOffsets(java.util.List<TopicPartition> partitions)` Get the first offset for the given topicPartitions.
`ConsumerMetricPerClientIdAndTopics`	`bytesFetchRequestSizeAvgMetric()` Average bytes per fetch request for each consumer and its topics.
`ConsumerMetricPerClientIdAndTopics`	`bytesPerSecondAvgMetric()` Average bytes consumed per second for each consumer and its topics.
`ConsumerMetricPerClientIdAndTopics`	`bytesTotalMetric()` Total bytes consumed per consumer and its topics.
`void`	`close()` Close the consumer, waiting for up to the default timeout of 30 seconds for any needed cleanup.
`void`	`close(java.time.Duration timeout)` Tries to close the consumer cleanly within the specified timeout.
`void`	`commitAsync()` Commit offsets returned on the last `poll()` for all the subscribed list of topics and partition.
`void`	`commitAsync(java.util.Map<TopicPartition,OffsetAndMetadata> offsets, OffsetCommitCallback offsetCommitCallback)` Commit the specified offsets for the specified list of topics and topicPartitions to Kafka.
`void`	`commitAsync(OffsetCommitCallback offsetCommitCallback)` Commit offsets returned on the last `poll()` for the subscribed list of topics and topicPartitions.
`void`	`commitSync()` Commit offsets returned on the last `poll()` for all the subscribed list of topics and topicPartitions.
`void`	`commitSync(java.util.Map<TopicPartition,OffsetAndMetadata> offsets)` Commit the specified offsets for the specified list of topics and topicPartitions.
`OffsetAndMetadata`	`committed(TopicPartition partition)` Get the last committed offset for the given partition (whether the commit happened by this process or another).
`java.util.Map<TopicPartition,java.lang.Long>`	`endOffsets(java.util.List<TopicPartition> partitions)` Get the end offsets for the given topicPartitions.
`ConsumerMetricPerClientId`	`fetchRequestAvgMetric()` The number of fetch requests per second.
`java.util.Map<java.lang.String,java.util.List<PartitionInfo>>`	`listTopics()` Get metadata about topicPartitions for all topics that the user is authorized to view.
`java.util.Map<MetricName,? extends org.apache.kafka.common.Metric>`	`metrics()` Get the metrics kept by the consumer.
`java.util.Map<TopicPartition,OffsetAndTimestamp>`	`offsetsForTimes(java.util.Map<TopicPartition,java.lang.Long> timestampsToSearch)` Look up the offsets for the given topicPartitions by timestamp.
`java.util.List<PartitionInfo>`	`partitionsFor(java.lang.String topic)` Get metadata about the topicPartitions for a given topic.
`void`	`pause(java.util.Collection<TopicPartition> partitions)` Suspend fetching from the requested topicPartitions.
`java.util.Set<TopicPartition>`	`paused()` Get the set of topicPartitions that were previously paused by a call to `pause(Collection)`.
`ConsumerRecords`	`poll(java.time.Duration timeout)` Fetch data for the topics or partitions specified using one of the subscribe/assign APIs.
`ConsumerRecords`	`poll(long timeout)` Fetch data for the topics or topicPartitions specified using one of the subscribe/assign APIs.
`long`	`position(TopicPartition partition)` Get the offset of the next record that will be fetched (if a record with that offset exists).
`ConsumerMetricPerClientIdAndTopicPartitions`	`recordsLagAvgPerTopicPartition()` The average lag of the partition.
`ConsumerMetricPerClientId`	`recordsLagMaxMetric()` The maximum lag in terms of number of records for any partition in this window.
`ConsumerMetricPerClientIdAndTopicPartitions`	`recordsLagMaxPerTopicPartition()` The max lag of the partition.
`ConsumerMetricPerClientIdAndTopicPartitions`	`recordsLagPerTopicPartition()` The latest lag of the partition.
`ConsumerMetricPerClientIdAndTopics`	`recordsPerRequestAvgMetric()` Average number of records gotten per fetch request for each consumer and its topics.
`ConsumerMetricPerClientIdAndTopics`	`recordsPerSecondAvgMetric()` Average number of records consumed per seconds for each consumer and its topics.
`ConsumerMetricPerClientIdAndTopics`	`recordsTotalMetric()` Total number of records consumed per consumer and its topics.
`void`	`resume(java.util.Collection<TopicPartition> partitions)` Resume specified topicPartitions which have been paused with `pause(Collection)`.
`void`	`seek(TopicPartition partition, long offset)` Overrides the fetch offsets that the consumer will use on the next `poll(timeout)`.
`void`	`seekToBeginning(TopicPartition... topicPartitions)` Seek to the first offset for each of the given topicPartitions.
`void`	`seekToEnd(TopicPartition... topicPartitions)` Seek to the last offset for each of the given topicPartitions.
`void`	`subscribe(java.util.List<java.lang.String> topics)` Subscribe to the given list of topics to get dynamically assigned topicPartitions.
`void`	`subscribe(java.util.List<java.lang.String> topics, ConsumerRebalanceListener consumerRebalanceListener)` Subscribe to the given list of topics to get dynamically assigned topicPartitions.
`void`	`subscribe(java.util.Map<java.lang.String,java.util.List<java.lang.String>> groupTopics)` Subscribe to the given list of tenantGroups and topics to get dynamically assigned topicPartitions.
`void`	`subscribe(java.util.Map<java.lang.String,java.util.List<java.lang.String>> groupTopics, ConsumerRebalanceListener consumerRebalanceListener)` Subscribe to the given list of tenantGroups and topics to get dynamically assigned topicPartitions.
`void`	`subscribe(java.util.regex.Pattern pattern, ConsumerRebalanceListener consumerRebalanceListener)` Subscribe to all topics matching specified pattern to get dynamically assigned topicPartitions.
`java.util.Set<java.lang.String>`	`subscription()` Get the current subscription.
`ConsumerMetricPerClientId`	`totalFetchRequestMetric()` Total number of fetch request for each consumer.
`void`	`unsubscribe()` Unsubscribe from topics currently subscribed with `subscribe(List)`.
`void`	`wakeup()` Wakeup the consumer.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Consumer
```
public Consumer()
```
- Method Detail
  - subscribe
```
public void subscribe(java.util.Map<java.lang.String,java.util.List<java.lang.String>> groupTopics)
```
    Subscribe to the given list of tenantGroups and topics to get dynamically assigned topicPartitions. Topic subscriptions are not incremental. This list will replace the current assignment (if there is one). Note that it is not possible to combine topic subscription with group management with manual partition assignment through assign(List). If the given list of topics is empty, it is treated the same as unsubscribe().
    As part of group management, the consumer will keep track of the list of consumers that belong to a particular group and will trigger a rebalance operation if one of the following events trigger l-
    - Number of topicPartitions change for any of the subscribed list of topics
    - Topic is created or deleted
    - An existing member of the consumer group dies
    - A new member is added to an existing consumer group via the join API
    When any of these events are triggered, the provided listener will be invoked first to indicate that the consumer's assignment has been revoked, and then again when the new assignment has been received. Note that this listener will immediately override any listener set in a previous call to subscribe. It is guaranteed, however, that the topicPartitions revoked/assigned through this interface are from topics subscribed in this call. See ConsumerRebalanceListener for more details.
    Parameters:
    
    groupTopics - The list of topics to subscribe to
    
    Throws:
    
    org.apache.commons.lang.NullArgumentException - if any argument is null
    
    DatabusClientRuntimeException - if subscription fails.
  - subscribe
```
public void subscribe(java.util.Map<java.lang.String,java.util.List<java.lang.String>> groupTopics,
                      ConsumerRebalanceListener consumerRebalanceListener)
```
    Subscribe to the given list of tenantGroups and topics to get dynamically assigned topicPartitions. Topic subscriptions are not incremental. This list will replace the current assignment (if there is one). Note that it is not possible to combine topic subscription with group management with manual partition assignment through assign(List). If the given list of topics is empty, it is treated the same as unsubscribe().
    As part of group management, the consumer will keep track of the list of consumers that belong to a particular group and will trigger a rebalance operation if one of the following events trigger l-
    - Number of topicPartitions change for any of the subscribed list of topics
    - Topic is created or deleted
    - An existing member of the consumer group dies
    - A new member is added to an existing consumer group via the join API
    When any of these events are triggered, the provided listener will be invoked first to indicate that the consumer's assignment has been revoked, and then again when the new assignment has been received. Note that this listener will immediately override any listener set in a previous call to subscribe. It is guaranteed, however, that the topicPartitions revoked/assigned through this interface are from topics subscribed in this call. See ConsumerRebalanceListener for more details.
    Parameters:
    
    groupTopics - The list of topics to subscribe to
    
    consumerRebalanceListener - Non-null listener getInstance to get notifications on partition assignment/revocation for the subscribed topics
    
    Throws:
    
    org.apache.commons.lang.NullArgumentException - if any argument is null
    
    DatabusClientRuntimeException - if subscription fails.
  - subscribe
```
public void subscribe(java.util.List<java.lang.String> topics,
                      ConsumerRebalanceListener consumerRebalanceListener)
```
    Subscribe to the given list of topics to get dynamically assigned topicPartitions. Topic subscriptions are not incremental. This list will replace the current assignment (if there is one). Note that it is not possible to combine topic subscription with group management with manual partition assignment through assign(List).
    If the given list of topics is empty, it is treated the same as unsubscribe().
    As part of group management, the consumer will keep track of the list of consumers that belong to a particular group and will trigger a rebalance operation if one of the following events trigger -
    - Number of topicPartitions change for any of the subscribed list of topics
    - Topic is created or deleted
    - An existing member of the consumer group dies
    - A new member is added to an existing consumer group via the join API
    When any of these events are triggered, the provided listener will be invoked first to indicate that the consumer's assignment has been revoked, and then again when the new assignment has been received. Note that this listener will immediately override any listener set in a previous call to subscribe. It is guaranteed, however, that the topicPartitions revoked/assigned through this interface are from topics subscribed in this call. See ConsumerRebalanceListener for more details.
    Parameters:
    
    topics - The non-null list of topics to subscribe to
    
    consumerRebalanceListener - Non-null listener getInstance to get notifications on partition assignment/revocation for the subscribed topics
    
    Throws:
    
    org.apache.commons.lang.NullArgumentException - if any argument is null
    
    DatabusClientRuntimeException - if subscription fails.
  - subscribe
```
public void subscribe(java.util.List<java.lang.String> topics)
```
    Subscribe to the given list of topics to get dynamically assigned topicPartitions. Topic subscriptions are not incremental. This list will replace the current assignment (if there is one). Note that it is not possible to combine topic subscription with group management with manual partition assignment through assign(List).
    If the given list of topics is empty, it is treated the same as unsubscribe().
    As part of group management, the consumer will keep track of the list of consumers that belong to a particular group and will trigger a rebalance operation if one of the following events trigger -
    - Number of topicPartitions change for any of the subscribed list of topics
    - Topic is created or deleted
    - An existing member of the consumer group dies
    - A new member is added to an existing consumer group via the join API
    When any of these events are triggered, the provided listener will be invoked first to indicate that the consumer's assignment has been revoked, and then again when the new assignment has been received. Note that this listener will immediately override any listener set in a previous call to subscribe. It is guaranteed, however, that the topicPartitions revoked/assigned through this interface are from topics subscribed in this call. See ConsumerRebalanceListener for more details.
    Parameters:
    
    topics - The list of topics to subscribe to
    
    Throws:
    
    org.apache.commons.lang.NullArgumentException - if any argument is null
    
    DatabusClientRuntimeException - if subscription fails.
  - assignment
```
public java.util.Set<TopicPartition> assignment()
```
    Get the set of topicPartitions currently assigned to this consumer. If subscription happened by directly assigning topicPartitions using assign(List) then this will simply return the same topicPartitions that were assigned. If topic subscription was used, then this will give the set of topic topicPartitions currently assigned to the consumer (which may be none if the assignment hasn't happened yet, or the topicPartitions are in the process of getting reassigned).
    
    Returns:
    
    The set of topicPartitions currently assigned to this consumer
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - subscription
```
public java.util.Set<java.lang.String> subscription()
```
    Get the current subscription. Will return the same topics used in the most recent call to subscribe(List, ConsumerRebalanceListener), or an empty set if no such call has been made.
    
    Returns:
    
    The set of topics currently subscribed to
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - assign
```
public void assign(java.util.List<TopicPartition> partitions)
```
    Manually assign a list of partition to this consumer. This interface does not allow for incremental assignment and will replace the previous assignment (if there is one).
    Manual topic assignment through this method does not use the consumer's group management functionality. As such, there will be no rebalance operation triggered when group membership or cluster and topic metadata change. Note that it is not possible to use both manual partition assignment with assign(List) and group assignment with subscribe(List, ConsumerRebalanceListener).
    
    Parameters:
    
    partitions - The list of topicPartitions to assign this consumer
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - subscribe
```
public void subscribe(java.util.regex.Pattern pattern,
                      ConsumerRebalanceListener consumerRebalanceListener)
```
    Subscribe to all topics matching specified pattern to get dynamically assigned topicPartitions. The pattern matching will be done periodically against topics existing at the time of check.
    As part of group management, the consumer will keep track of the list of consumers that belong to a particular group and will trigger a rebalance operation if one of the following events trigger -
    - Number of topicPartitions change for any of the subscribed list of topics
    - Topic is created or deleted
    - An existing member of the consumer group dies
    - A new member is added to an existing consumer group via the join API
    Parameters:
    
    pattern - Pattern to subscribe to
    
    consumerRebalanceListener - consumer listener for rebalancing databus operations
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - unsubscribe
```
public void unsubscribe()
```
    Unsubscribe from topics currently subscribed with subscribe(List). This also clears any topicPartitions directly assigned through assign(List).
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - poll
```
public ConsumerRecords poll(long timeout)
```
    Fetch data for the topics or topicPartitions specified using one of the subscribe/assign APIs. It is an error to not have subscribed to any topics or topicPartitions before polling for data.
    On each poll, consumer will try to use the last consumed offset as the starting offset and fetch sequentially. The last consumed offset can be manually set through seek(TopicPartition, long) or automatically set as the last committed offset for the subscribed list of topicPartitions
    Parameters:
    
    timeout - The time, in milliseconds, spent waiting in poll if data is not available. If 0, returns immediately with any records that are available now. Must not be negative.
    
    Returns:
    
    map of topic to records since the last fetch for the subscribed list of topics and topicPartitions
    
    Throws:
    DatabusClientRuntimeException - if poll fails.The original cause could be any of these exceptions:
    
    org.apache.kafka.clients.consumer.InvalidOffsetException if the offset for a partition or set of topicPartitions is undefined or out of range and no offset reset policy has been configured
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if caller does Read access to any of the subscribed topics or to the configured groupId
    org.apache.kafka.common.KafkaException for any other unrecoverable errors (e.g. invalid groupId or session timeout, errors deserializing key/value pairs, or any new error cases in future versions)
  - poll
```
public ConsumerRecords poll(java.time.Duration timeout)
```
    Fetch data for the topics or partitions specified using one of the subscribe/assign APIs. It is an error to not have subscribed to any topics or partitions before polling for data.
    On each poll, consumer will try to use the last consumed offset as the starting offset and fetch sequentially. The last consumed offset can be manually set through seek(TopicPartition, long) or automatically set as the last committed offset for the subscribed list of partitions
    This method returns immediately if there are records available. Otherwise, it will await the passed timeout. If the timeout expires, an empty record set will be returned. Note that this method may block beyond the timeout in order to execute custom ConsumerRebalanceListener callbacks.
    Parameters:
    
    timeout - The time, in milliseconds, spent waiting in poll if data is not available. If 0, returns immediately with any records that are available now. Must not be negative.
    
    Returns:
    
    map of topic to records since the last fetch for the subscribed list of topics and topicPartitions
    
    Throws:
    DatabusClientRuntimeException - if poll fails.The original cause could be any of these exceptions:
    
    org.apache.kafka.clients.consumer.InvalidOffsetException if the offset for a partition or set of partitions is undefined or out of range and no offset reset policy has been configured
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.InterruptException if the calling thread is interrupted before or while this function is called
    org.apache.kafka.common.errors.AuthenticationException if authentication fails. See the exception for more details
    org.apache.kafka.common.errors.AuthorizationException if caller lacks Read access to any of the subscribed topics or to the configured groupId. See the exception for more details
    org.apache.kafka.common.KafkaException for any other unrecoverable errors (e.g. invalid groupId or session timeout, errors deserializing key/value pairs, or any new error cases in future versions)
    java.lang.IllegalArgumentException if the timeout value is negative
    java.lang.IllegalStateException if the consumer is not subscribed to any topics or manually assigned any partitions to consume from
    java.lang.ArithmeticException if the timeout is greater than Long.MAX_VALUE milliseconds.
    org.apache.kafka.common.errors.InvalidTopicException if the current subscription contains any invalid topic (per org.apache.kafka.common.internals.Topic#validate(String))
    org.apache.kafka.common.errors.FencedInstanceIdException if this consumer instance gets fenced by broker.
  - commitSync
```
public void commitSync()
```
    Commit offsets returned on the last poll() for all the subscribed list of topics and topicPartitions.
    This commits offsets only to Kafka. The offsets committed using this API will be used on the first fetch after every rebalance and also on startup. As such, if you need to store offsets in anything other than Kafka, this API should not be used.
    This is a synchronous commits and will block until either the commit succeeds or an unrecoverable error is encountered (in which case it is thrown to the caller).
    Throws:
    DatabusClientRuntimeException - if a commitSync fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.clients.consumer.CommitFailedException if the commit failed and cannot be retried. This can only occur if you are using automatic group management with subscribe(List), or if there is an active group with the same groupId which is using group management.
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic or to the configured groupId
    org.apache.kafka.common.KafkaException for any other unrecoverable errors (e.g. if offset metadata is too large or if the committed offset is invalid).
  - commitSync
```
public void commitSync(java.util.Map<TopicPartition,OffsetAndMetadata> offsets)
```
    Commit the specified offsets for the specified list of topics and topicPartitions.
    This commits offsets to Kafka. The offsets committed using this API will be used on the first fetch after every rebalance and also on startup. As such, if you need to store offsets in anything other than Kafka, this API should not be used.
    This is a synchronous commits and will block until either the commit succeeds or an unrecoverable error is encountered (in which case it is thrown to the caller).
    Parameters:
    
    offsets - A map of offsets by partition with associated metadata
    
    Throws:
    DatabusClientRuntimeException - if commitSync fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.clients.consumer.CommitFailedException if the commit failed and cannot be retried. This can only occur if you are using automatic group management with subscribe(List), or if there is an active group with the same groupId which is using group management.
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic or to the configured groupId
    org.apache.kafka.common.KafkaException for any other unrecoverable errors (e.g. if offset metadata is too large or if the committed offset is invalid).
  - commitAsync
```
public void commitAsync()
```
    Commit offsets returned on the last poll() for all the subscribed list of topics and partition. Same as commitAsync(null)
    
    Throws:
    
    DatabusClientRuntimeException - if a commitAsync fails
  - commitAsync
```
public void commitAsync(OffsetCommitCallback offsetCommitCallback)
```
    Commit offsets returned on the last poll() for the subscribed list of topics and topicPartitions.
    This commits offsets only to Kafka. The offsets committed using this API will be used on the first fetch after every rebalance and also on startup. As such, if you need to store offsets in anything other than Kafka, this API should not be used.
    This is an asynchronous call and will not block. Any errors encountered are either passed to the callback (if provided) or discarded.
    
    Parameters:
    
    offsetCommitCallback - Callback to invoke when the commit completes
    
    Throws:
    
    DatabusClientRuntimeException - if a commitAsync fails
  - seek
```
public void seek(TopicPartition partition,
                 long offset)
```
    Overrides the fetch offsets that the consumer will use on the next poll(timeout). If this API is invoked for the same partition more than once, the latest offset will be used on the next poll(). Note that you may lose data if this API is arbitrarily used in the middle of consumption, to reset the fetch offsets
    
    Parameters:
    
    partition - partition to seek
    
    offset - offset to seek
    
    Throws:
    
    DatabusClientRuntimeException - if a seek fails
  - seekToBeginning
```
public void seekToBeginning(TopicPartition... topicPartitions)
```
    Seek to the first offset for each of the given topicPartitions. This function evaluates lazily, seeking to the final offset in all topicPartitions only when poll(long) or position(TopicPartition) are called.
    
    Parameters:
    
    topicPartitions - topicPartitions to seek
    
    Throws:
    
    DatabusClientRuntimeException - if it fails
  - seekToEnd
```
public void seekToEnd(TopicPartition... topicPartitions)
```
    Seek to the last offset for each of the given topicPartitions. This function evaluates lazily, seeking to the final offset in all topicPartitions only when poll(long) or position(TopicPartition) are called.
    
    Parameters:
    
    topicPartitions - topicPartitions to seek
    
    Throws:
    
    DatabusClientRuntimeException - if it fails
  - position
```
public long position(TopicPartition partition)
```
    Get the offset of the next record that will be fetched (if a record with that offset exists).
    Parameters:
    
    partition - The partition to get the position for
    
    Returns:
    
    The offset
    
    Throws:
    DatabusClientRuntimeException - if position fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.clients.consumer.InvalidOffsetException if no offset is currently defined for the partition
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic or to the configured groupId
    org.apache.kafka.common.KafkaException for any other unrecoverable errors
  - committed
```
public OffsetAndMetadata committed(TopicPartition partition)
```
    Get the last committed offset for the given partition (whether the commit happened by this process or another). This offset will be used as the position for the consumer in the event of a failure.
    This call may block to do a remote call if the partition in question isn't assigned to this consumer or if the consumer hasn't yet initialized its cache of committed offsets.
    Parameters:
    
    partition - The partition to check
    
    Returns:
    
    The last committed offset and metadata or null if there was no prior commit
    
    Throws:
    DatabusClientRuntimeException - if committed fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic or to the configured groupId
    org.apache.kafka.common.KafkaException for any other unrecoverable errors
  - metrics
```
public java.util.Map<MetricName,? extends org.apache.kafka.common.Metric> metrics()
```
    Get the metrics kept by the consumer.
    
    Returns:
    
    a map of metrics
    
    Throws:
    
    DatabusClientRuntimeException - if metrics fails.
  - recordsPerSecondAvgMetric
```
public ConsumerMetricPerClientIdAndTopics recordsPerSecondAvgMetric()
```
    Average number of records consumed per seconds for each consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - recordsTotalMetric
```
public ConsumerMetricPerClientIdAndTopics recordsTotalMetric()
```
    Total number of records consumed per consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - bytesPerSecondAvgMetric
```
public ConsumerMetricPerClientIdAndTopics bytesPerSecondAvgMetric()
```
    Average bytes consumed per second for each consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - bytesTotalMetric
```
public ConsumerMetricPerClientIdAndTopics bytesTotalMetric()
```
    Total bytes consumed per consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - recordsPerRequestAvgMetric
```
public ConsumerMetricPerClientIdAndTopics recordsPerRequestAvgMetric()
```
    Average number of records gotten per fetch request for each consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - totalFetchRequestMetric
```
public ConsumerMetricPerClientId totalFetchRequestMetric()
```
    Total number of fetch request for each consumer. A fetch is not equals poll(). A Kafka fetch is governed by a set of consumer configuration prooperties like fetch.min.bytes, fetch.max.wait.ms, max.topicPartitions.fetch.bytes, etc. There might be more poll than fetch request.
    
    Returns:
    
    ConsumerMetricPerClientId instance.
  - fetchRequestAvgMetric
```
public ConsumerMetricPerClientId fetchRequestAvgMetric()
```
    The number of fetch requests per second.
    
    Returns:
    
    ConsumerMetricPerClientId instance
  - recordsLagMaxMetric
```
public ConsumerMetricPerClientId recordsLagMaxMetric()
```
    The maximum lag in terms of number of records for any partition in this window.
    
    Returns:
    
    ConsumerMetricPerClientId instance.
  - bytesFetchRequestSizeAvgMetric
```
public ConsumerMetricPerClientIdAndTopics bytesFetchRequestSizeAvgMetric()
```
    Average bytes per fetch request for each consumer and its topics.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopics instance.
  - recordsLagPerTopicPartition
```
public ConsumerMetricPerClientIdAndTopicPartitions recordsLagPerTopicPartition()
```
    The latest lag of the partition.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopicPartitions instance.
  - recordsLagAvgPerTopicPartition
```
public ConsumerMetricPerClientIdAndTopicPartitions recordsLagAvgPerTopicPartition()
```
    The average lag of the partition.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopicPartitions instance.
  - recordsLagMaxPerTopicPartition
```
public ConsumerMetricPerClientIdAndTopicPartitions recordsLagMaxPerTopicPartition()
```
    The max lag of the partition.
    
    Returns:
    
    ConsumerMetricPerClientIdAndTopicPartitions instance.
  - partitionsFor
```
public java.util.List<PartitionInfo> partitionsFor(java.lang.String topic)
```
    Get metadata about the topicPartitions for a given topic. This method will issue a remote call to the server if it does not already have any metadata about the given topic.
    Parameters:
    
    topic - The topic to get partition metadata for
    
    Returns:
    
    The list of topicPartitions
    
    Throws:
    DatabusClientRuntimeException - if partitionsFor fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the specified topic
    org.apache.kafka.common.errors.TimeoutException if the topic metadata could not be fetched before expiration of the configured request timeout
    org.apache.kafka.common.KafkaException for any other unrecoverable errors
  - listTopics
```
public java.util.Map<java.lang.String,java.util.List<PartitionInfo>> listTopics()
```
    Get metadata about topicPartitions for all topics that the user is authorized to view. This method will issue a remote call to the server.
    Returns:
    
    The map of topics and its topicPartitions
    
    Throws:
    DatabusClientRuntimeException - if listTopics fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.WakeupException if wakeup() is called before or while this function is called
    org.apache.kafka.common.errors.TimeoutException if the topic metadata could not be fetched before expiration of the configured request timeout
    org.apache.kafka.common.KafkaException for any other unrecoverable errors
  - pause
```
public void pause(java.util.Collection<TopicPartition> partitions)
```
    Suspend fetching from the requested topicPartitions. Future calls to poll(long) will not return any records from these topicPartitions until they have been resumed using resume(Collection). Note that this method does not affect partition subscription. In particular, it does not cause a group rebalance when automatic assignment is used.
    
    Parameters:
    
    partitions - The topicPartitions which should be paused
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - resume
```
public void resume(java.util.Collection<TopicPartition> partitions)
```
    Resume specified topicPartitions which have been paused with pause(Collection). New calls to poll(long) will return records from these topicPartitions if there are any to be fetched. If the topicPartitions were not previously paused, this method is a no-op.
    
    Parameters:
    
    partitions - The topicPartitions which should be resumed
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - close
```
public void close()
```
    Close the consumer, waiting for up to the default timeout of 30 seconds for any needed cleanup. If auto-commit is enabled, this will commit the current offsets if possible within the default timeout. See close(Duration) for details. Note that wakeup() cannot be used to interrupt close.
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - close
```
public void close(java.time.Duration timeout)
```
    Tries to close the consumer cleanly within the specified timeout. This method waits up to timeout for the consumer to complete pending commits and leave the group. If auto-commit is enabled, this will commit the current offsets if possible within the timeout. If the consumer is unable to complete offset commits and gracefully leave the group before the timeout expires, the consumer is force closed. Note that wakeup() cannot be used to interrupt close.
    
    Parameters:
    
    timeout - The maximum time to wait for consumer to close gracefully. The value must be non-negative. Specifying a timeout of zero means do not wait for pending requests to complete.
    
    Throws:
    
    DatabusClientRuntimeException - If there is a error
  - wakeup
```
public void wakeup()
```
    Wakeup the consumer. This method is thread-safe and is useful in particular to abort a long poll. The thread which is blocking in an operation will throw WakeupException.
    
    Throws:
    
    DatabusClientRuntimeException - if it fails.
  - commitAsync
```
public void commitAsync(java.util.Map<TopicPartition,OffsetAndMetadata> offsets,
                        OffsetCommitCallback offsetCommitCallback)
```
    Commit the specified offsets for the specified list of topics and topicPartitions to Kafka.
    This commits offsets to Kafka. The offsets committed using this API will be used on the first fetch after every rebalance and also on startup. As such, if you need to store offsets in anything other than Kafka, this API should not be used.
    This is an asynchronous call and will not block. Any errors encountered are either passed to the callback (if provided) or discarded.
    
    Parameters:
    
    offsets - A map of offsets by partition with associate metadata. This map will be copied internally, so it is safe to mutate the map after returning.
    
    offsetCommitCallback - Callback to invoke when the commit completes.
    
    Throws:
    
    DatabusClientRuntimeException - if it fails
  - offsetsForTimes
```
public java.util.Map<TopicPartition,OffsetAndTimestamp> offsetsForTimes(java.util.Map<TopicPartition,java.lang.Long> timestampsToSearch)
```
    Look up the offsets for the given topicPartitions by timestamp. The returned offset for each partition is the earliest offset whose timestamp is greater than or equal to the given timestamp in the corresponding partition.
    This is a blocking call. The consumer does not have to be assigned the topicPartitions. If the message format version in a partition is before 0.10.0, i.e. the messages do not have timestamps, null will be returned for that partition.
    Parameters:
    
    timestampsToSearch - the mapping from partition to the timestamp to look up.
    
    Returns:
    
    a mapping from partition to the timestamp and offset of the first message with timestamp greater than or equal to the target timestamp. null will be returned for the partition if there is no such message.
    
    Throws:
    DatabusClientRuntimeException - if it fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.AuthenticationException if authentication fails. See the exception for more details org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic(s). See the exception for more details
    IllegalArgumentException if the target timestamp is negative
    org.apache.kafka.common.errors.TimeoutException if the offset metadata could not be fetched before the amount of time allocated by default.api.timeout.ms expires.
    org.apache.kafka.common.errors.UnsupportedVersionException if the broker does not support looking up the offsets by timestamp
  - beginningOffsets
```
public java.util.Map<TopicPartition,java.lang.Long> beginningOffsets(java.util.List<TopicPartition> partitions)
```
    Get the first offset for the given topicPartitions.
    This method does not change the current consumer position of the topicPartitions. *
    Parameters:
    
    partitions - the topicPartitions to get the earliest offsets.
    
    Returns:
    
    The earliest available offsets for the given topicPartitions
    
    Throws:
    DatabusClientRuntimeException - if it fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.AuthenticationException if authentication fails. See the exception for more details
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic(s). See the exception for more details
    org.apache.kafka.common.errors.TimeoutException if the offset metadata could not be fetched before expiration of the configured default.api.timeout.ms
  - endOffsets
```
public java.util.Map<TopicPartition,java.lang.Long> endOffsets(java.util.List<TopicPartition> partitions)
```
    Get the end offsets for the given topicPartitions. In the default read_uncommitted isolation level, the end offset is the high watermark (that is, the offset of the last successfully replicated message plus one). For read_committed consumers, the end offset is the last stable offset (LSO), which is the minimum of the high watermark and the smallest offset of any open transaction. Finally, if the partition has never been written to, the end offset is 0.
    This method does not change the current consumer position of the topicPartitions.
    Parameters:
    
    partitions - the topicPartitions to get the end offsets.
    
    Returns:
    
    The end offsets for the given topicPartitions.
    
    Throws:
    DatabusClientRuntimeException - if it fails. The original cause could be any of these exceptions:
    
    org.apache.kafka.common.errors.AuthenticationException if authentication fails. See the exception for more details
    org.apache.kafka.common.errors.AuthorizationException if not authorized to the topic(s). See the exception for more details
    org.apache.kafka.common.errors.TimeoutException if the offset metadata could not be fetched before the amount of time allocated by request.timeout.ms expires
  - paused
```
public java.util.Set<TopicPartition> paused()
```
    Get the set of topicPartitions that were previously paused by a call to pause(Collection).
    
    Returns:
    
    The set of paused topicPartitions

Class Consumer<P>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Consumer

Method Detail

subscribe

subscribe

subscribe

subscribe

assignment

subscription

assign

subscribe

unsubscribe

poll

poll

commitSync

commitSync

commitAsync

commitAsync

seek

seekToBeginning

seekToEnd

position

committed

metrics

recordsPerSecondAvgMetric

recordsTotalMetric

bytesPerSecondAvgMetric

bytesTotalMetric

recordsPerRequestAvgMetric

totalFetchRequestMetric

fetchRequestAvgMetric

recordsLagMaxMetric

bytesFetchRequestSizeAvgMetric

recordsLagPerTopicPartition

recordsLagAvgPerTopicPartition

recordsLagMaxPerTopicPartition

partitionsFor

listTopics

pause

resume

close

close

wakeup

commitAsync

offsetsForTimes

beginningOffsets

endOffsets

paused