Table of Contents |
---|
Current state: "DISCUSS"Adopted
Discussion thread:
JIRA: KAFKA-12313
Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
Motivation
KIP-659 introduced a config windowSize to TimeWindowedDeserializer which discourages the setting of windowSize to Long.MAX_VALUE as the default value. However, there is still a possibility of setting the config only for innerClassSerde or only for windowSize. This KIP aims at standardising the way
...
the serialisers and deserializer object can be created for the usage in console consumer, plain consumer and via the DSL.
...
Proposed Changes
Here are the changes being proposed in the KIP:
- StreamsConfig
- Deprecate default.windowed.key.serde.inner
...
- and default.windowed.
...
- value.serde.inner
...
- .
- Introduce a new config called windowed
...
- .inner.class
...
- .serde. This way, the config comes closer to the window.size.
...
- ms config introduced in KIP-659 and it also emphasises that the config isn't really a default one.
...
- ConsoleConsumer
- It would be mandatory to pass windowed.inner.class.serde and window.size.ms config.
- The following table discusses the proposed changes for the Windowed Serdes and proposed changes based on Client Type.
Windowed Serde Type Client Type Constructor Invoked Proposed Change 1 TimeWindowedDeserializer
Console Consumer Default constructor Ensure both windowSize and Serde class configs are set. Throw error if not. Plain Consumer Default OR Parameterised Ok to use either as long as the configs supplied don't conflict. Kafka Streams Parameterised User supplies parameters by constructing a TimeWindowedSerde object. No change 2 TimeWindowedSerializer Console Producer Default constructor Ensure Serde class config is set. Throw error if not. Plain Producer Default OR Parameterised Ok to use either as long as the configs supplied don't conflict. Kafka Streams Parameterised User supplies parameters by constructing a TimeWindowedSerde object. No change 3 SessionWindowedDeserializer Console consumer Default constructor Ensure Serde class config is set. Throw error if not. Plain consumer Default OR Parameterised Ok to use either as long as the configs supplied don't conflict. Kafka Streams Parameterised User supplies parameters by constructing a SessionWindowedSerde object. No change 4 SessionWindowedSerializer Console Producer Default constructor Ensure Serde class config is set. Throw error if not. Plain Producer Default OR Parameterised Ok to use either as long as the configs supplied don't conflict. Kafka Streams Parameterised User supplies parameters by constructing a SessionWindowedSerde object. No change
Public Interfaces
- StreamsConfig:
...
Proposed Changes
Here are the changes being proposed in the KIP:
- Rename the
- Deprecate
- default.windowed.key.serde.inner
- and default.windowed.
- value.serde.inner
- in StreamConfig.
- Deprecate default.windowed.value.serde.inner in StreamConfig.
- If the users want to run Console consumer for testing purposes, then it will invoke the default constructor of TimeWindowedDeserializer. We will ensure that both the configs (windowSize and deserialiser class) are set and if they aren't then an error would be thrown.
- For any other plain consumer client, the user can pass them in as configs OR pass the parameters to the TimeWindowedDeserializer constructor, and then pass that object to the consumer. It is ok for the user to pass both as long as there is no conflict between the params passed via constructor and via the configs.
Public Interfaces
-
- Introduce a new config called windowed.inner.class.serde.
Code Block language java theme Midnight public static final String WINDOWED_INNER_CLASS_SERDE = "windowed.inner.class.serde"; private static final String WINDOWED_INNER_CLASS_SERDE_DOC = " Serde for the inner class of a windowed record. Must implement the " + "<code>org.apache.kafka.common.serialization.Serde</code> interface. Note that setting this config in KafkaStreams application would result " + "in an error as it is meant to be used only from Plain consumer client."; @Deprecated public static final String DEFAULT_WINDOWED_KEY_SERDE_INNER_CLASS = "default.windowed.key.serde.inner"; @Deprecated public static final String DEFAULT_WINDOWED_VALUE_SERDE_INNER_CLASS = "default.windowed.value.serde.inner";
- Introduce a new config called windowed.inner.class.serde.
-
Compatibility, Deprecation, and Migration Plan
This KIP deprecates following 2 configs in StreamConfig : default.
...
windowed.key.serde.inner
...
and default.windowed.value.serde.inner
Rejected Alternatives
N/A