What does "offsets.topic.compression.codec" in kafka actually do? - apache-kafka

Very recently we started to get MessageSizeTooLargeException on the metadata, so we enabled offsets.topic.compression.codec=1, to enable gzip compression, but the overall bytes in rate/messages in rate to the broker hasnt changed. Am i missing something? Is there some other property which needs to be changed?
How does this codec work?
Do we need to add some property on consumers and producers as well? I have just enabled this on the broker.

offsets.topic.compression.codec is only for the internal offset topic (namely __consumer_offsets). It is no use for those user-level topics.
See Kafka: Sending a 15MB message on how to avoid MessageTooLargeException/RecordTooLargeException.

Related

How do I usually set "batch.size" and "buffer.memory" in Apache Kafka? [duplicate]

I send String-messages to Kafka V. 0.8 with the Java Producer API.
If the message size is about 15 MB I get a MessageSizeTooLargeException.
I have tried to set message.max.bytesto 40 MB, but I still get the exception. Small messages worked without problems.
(The exception appear in the producer, I don't have a consumer in this application.)
What can I do to get rid of this exception?
My example producer config
private ProducerConfig kafkaConfig() {
Properties props = new Properties();
props.put("metadata.broker.list", BROKERS);
props.put("serializer.class", "kafka.serializer.StringEncoder");
props.put("request.required.acks", "1");
props.put("message.max.bytes", "" + 1024 * 1024 * 40);
return new ProducerConfig(props);
}
Error-Log:
4709 [main] WARN kafka.producer.async.DefaultEventHandler - Produce request with correlation id 214 failed due to [datasift,0]: kafka.common.MessageSizeTooLargeException
4869 [main] WARN kafka.producer.async.DefaultEventHandler - Produce request with correlation id 217 failed due to [datasift,0]: kafka.common.MessageSizeTooLargeException
5035 [main] WARN kafka.producer.async.DefaultEventHandler - Produce request with correlation id 220 failed due to [datasift,0]: kafka.common.MessageSizeTooLargeException
5198 [main] WARN kafka.producer.async.DefaultEventHandler - Produce request with correlation id 223 failed due to [datasift,0]: kafka.common.MessageSizeTooLargeException
5305 [main] ERROR kafka.producer.async.DefaultEventHandler - Failed to send requests for topics datasift with correlation ids in [213,224]
kafka.common.FailedToSendMessageException: Failed to send messages after 3 tries.
at kafka.producer.async.DefaultEventHandler.handle(Unknown Source)
at kafka.producer.Producer.send(Unknown Source)
at kafka.javaapi.producer.Producer.send(Unknown Source)
You need to adjust three (or four) properties:
Consumer side:fetch.message.max.bytes - this will determine the largest size of a message that can be fetched by the consumer.
Broker side: replica.fetch.max.bytes - this will allow for the replicas in the brokers to send messages within the cluster and make sure the messages are replicated correctly. If this is too small, then the message will never be replicated, and therefore, the consumer will never see the message because the message will never be committed (fully replicated).
Broker side: message.max.bytes - this is the largest size of the message that can be received by the broker from a producer.
Broker side (per topic): max.message.bytes - this is the largest size of the message the broker will allow to be appended to the topic. This size is validated pre-compression. (Defaults to broker's message.max.bytes.)
I found out the hard way about number 2 - you don't get ANY exceptions, messages, or warnings from Kafka, so be sure to consider this when you are sending large messages.
Minor changes required for Kafka 0.10 and the new consumer compared to laughing_man's answer:
Broker: No changes, you still need to increase properties message.max.bytes and replica.fetch.max.bytes. message.max.bytes has to be equal or smaller(*) than replica.fetch.max.bytes.
Producer: Increase max.request.size to send the larger message.
Consumer: Increase max.partition.fetch.bytes to receive larger messages.
(*) Read the comments to learn more about message.max.bytes<=replica.fetch.max.bytes
The answer from #laughing_man is quite accurate. But still, I wanted to give a recommendation which I learned from Kafka expert Stephane Maarek. We actively applied this solution in our live systems.
Kafka isn’t meant to handle large messages.
Your API should use cloud storage (for example, AWS S3) and simply push a reference to S3 to Kafka or any other message broker. You'll need to find a place to save your data, whether it can be a network drive or something else entirely, but it shouldn't be a message broker.
If you don't want to proceed with the recommended and reliable solution above,
The message max size is 1MB (the setting in your brokers is called message.max.bytes) Apache Kafka. If you really needed it badly, you could increase that size and make sure to increase the network buffers for your producers and consumers.
And if you really care about splitting your message, make sure each message split has the exact same key so that it gets pushed to the same partition, and your message content should report a “part id” so that your consumer can fully reconstruct the message.
If the message is text-based try to compress the data, which may reduce the data size, but not magically.
Again, you have to use an external system to store that data and just push an external reference to Kafka. That is a very common architecture and one you should go with and widely accepted.
Keep that in mind Kafka works best only if the messages are huge in amount but not in size.
Source: https://www.quora.com/How-do-I-send-Large-messages-80-MB-in-Kafka
The idea is to have equal size of message being sent from Kafka Producer to Kafka Broker and then received by Kafka Consumer i.e.
Kafka producer --> Kafka Broker --> Kafka Consumer
Suppose if the requirement is to send 15MB of message, then the Producer, the Broker and the Consumer, all three, needs to be in sync.
Kafka Producer sends 15 MB --> Kafka Broker Allows/Stores 15 MB --> Kafka Consumer receives 15 MB
The setting therefore should be:
a) on Broker:
message.max.bytes=15728640
replica.fetch.max.bytes=15728640
b) on Consumer:
fetch.message.max.bytes=15728640
You need to override the following properties:
Broker Configs($KAFKA_HOME/config/server.properties)
replica.fetch.max.bytes
message.max.bytes
Consumer Configs($KAFKA_HOME/config/consumer.properties)
This step didn't work for me. I add it to the consumer app and it was working fine
fetch.message.max.bytes
Restart the server.
look at this documentation for more info:
http://kafka.apache.org/08/configuration.html
I think, most of the answers here are kind of outdated or not entirely complete.
To refer on the answer of Sacha Vetter (with the update for Kafka 0.10), I'd like to provide some additional Information and links to the official documentation.
Producer Configuration:
max.request.size (Link) has to be increased for files bigger than 1 MB, otherwise they are rejected
Broker/Topic configuration:
message.max.bytes (Link) may be set, if one like to increase the message size on broker level. But, from the documentation: "This can be set per topic with the topic level max.message.bytes config."
max.message.bytes (Link) may be increased, if only one topic should be able to accept lager files. The broker configuration must not be changed.
I'd always prefer a topic-restricted configuration, due to the fact, that I can configure the topic by myself as a client for the Kafka cluster (e.g. with the admin client). I may not have any influence on the broker configuration itself.
In the answers from above, some more configurations are mentioned as necessary:
replica.fetch.max.bytes (Link) (Broker config)
From the documentation: "This is not an absolute maximum, if the first record batch in the first non-empty partition of the fetch is larger than this value, the record batch will still be returned to ensure that progress can be made."
max.partition.fetch.bytes (Link) (Consumer config)
From the documentation: "Records are fetched in batches by the consumer. If the first record batch in the first non-empty partition of the fetch is larger than this limit, the batch will still be returned to ensure that the consumer can make progress."
fetch.max.bytes (Link) (Consumer config; not mentioned above, but same category)
From the documentation: "Records are fetched in batches by the consumer, and if the first record batch in the first non-empty partition of the fetch is larger than this value, the record batch will still be returned to ensure that the consumer can make progress."
Conclusion: The configurations regarding fetching messages are not necessary to change for processing messages, lager than the default values of these configuration (had this tested in a small setup). Probably, the consumer may always get batches of size 1. However, two of the configurations from the first block has to be set, as mentioned in the answers before.
This clarification should not tell anything about performance and should not be a recommendation to set or not to set these configuration. The best values has to be evaluated individually depending on the concrete planned throughput and data structure.
One key thing to remember that message.max.bytes attribute must be in sync with the consumer's fetch.message.max.bytes property. the fetch size must be at least as large as the maximum message size otherwise there could be situation where producers can send messages larger than the consumer can consume/fetch. It might worth taking a look at it.
Which version of Kafka you are using? Also provide some more details trace that you are getting. is there some thing like ... payload size of xxxx larger
than 1000000 coming up in the log?
For people using landoop kafka:
You can pass the config values in the environment variables like:
docker run -d --rm -p 2181:2181 -p 3030:3030 -p 8081-8083:8081-8083 -p 9581-9585:9581-9585 -p 9092:9092
-e KAFKA_TOPIC_MAX_MESSAGE_BYTES=15728640 -e KAFKA_REPLICA_FETCH_MAX_BYTES=15728640 landoop/fast-data-dev:latest `
This sets topic.max.message.bytes and replica.fetch.max.bytes on the broker.
And if you're using rdkafka then pass the message.max.bytes in the producer config like:
const producer = new Kafka.Producer({
'metadata.broker.list': 'localhost:9092',
'message.max.bytes': '15728640',
'dr_cb': true
});
Similarly, for the consumer,
const kafkaConf = {
"group.id": "librd-test",
"fetch.message.max.bytes":"15728640",
... .. }
Here is how I achieved successfully sending data up to 100mb using kafka-python==2.0.2:
Broker:
consumer = KafkaConsumer(
...
max_partition_fetch_bytes=max_bytes,
fetch_max_bytes=max_bytes,
)
Producer (See final solution at the end):
producer = KafkaProducer(
...
max_request_size=KafkaSettings.MAX_BYTES,
)
Then:
producer.send(topic, value=data).get()
After sending data like this, the following exception appeared:
MessageSizeTooLargeError: The message is n bytes when serialized which is larger than the total memory buffer you have configured with the buffer_memory configuration.
Finally I increased buffer_memory (default 32mb) to receive the message on the other end.
producer = KafkaProducer(
...
max_request_size=KafkaSettings.MAX_BYTES,
buffer_memory=KafkaSettings.MAX_BYTES * 3,
)

ksqlDB - How to set batch.size and linger.ms for producers to optimise compression

When configuring ksqlDB I can set the option ksql.streams.producer.compression.type which enables compression for ksqlDB's internal producers. Thus when I create a ksqlDB stream, it's output topic will be compressed with the selected compression type.
However, as far as I have understood the compression performance is heavily impacted by how much batching the producer does. Therefore, I wish to be able to configure the batch.size and linger.ms parameters for ksqlDB's producers. Does anyone know if and how these parameters can be set for ksqlDB?
Thanks to Matthias J Sax for answering my question on the Confluent Community Slack channel: https://app.slack.com/client/T47H7EWH0/threads?cdn_fallback=1
There is an info-box in the documentation.
That explains it pretty well:
KSQL documentation info box
The underlying producer and consumer clients in ksqlDB's server can be
modified with any valid properties. Simply use the form
ksql.streams.producer.xxx, ksql.streams.consumer.xxx to pass the
property through. For example, ksql.streams.producer.compression.type
sets the compression type on the producer.
Source: https://docs.ksqldb.io/en/latest/reference/server-configuration/

kafka stream state store issue with max.request.size paramater

We are using Kafka streams state store in the project, and we want to store more than 1MB of data, but we got below exception:
The message is 1760923 bytes when serialized which is larger than the
maximum request size you have configured with the max.request.size
configuration.
Then I followed the link Add prefix to StreamsConfig to enable setting default internal topic configs and added the following config:
topic.max.request.size=50000000
Then application works fine, and it can works fine when state store internal topic had been created but when Kafka been restarted and the state store topic had been lost/delete, then the Kafka stream processor need to create the internal state store topic automatically when start the application, at that moment, it throw exception which says:
"Aorg.apache.kafka.streams.errors.StreamsException: Could not create topic data-msg-seq-state-store-changelog. at org.apache.kafka.streams.processor.internals.InternalTopicManager.makeReady(InternalTopicManager.java:148)....
.....
org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:805) at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:774) Caused by: org.apache.kafka.common.errors.InvalidConfigurationException: Unknown topic config name: max.request.size".
The solution is we can manually create the internal topic, but that should not be good one.
Can you help me on this issue? If there is any config I have missed?
Thanks very much.
17 June 2020 update: still not resolve the issue. anyone can help?
The solution that you are looking for lies in the Kafka Stream's configuration properties that you set before starting the stream.
props.put(StreamsConfig.PRODUCER_PREFIX + ProducerConfig.MAX_REQUEST_SIZE_CONFIG, "5242880");
The value I used here is 5 MB in bytes. You can change the value to suit your needs.
I don't see a configuration with max.request.size. May be it is max.message.bytes (Topic configuration reference). So, you may try setting this.
You can refer to the broker setting max.message.bytes and increase it. It sets it at the broker level.
Documentation states:
The largest record batch size allowed by Kafka (after compression if
compression is enabled). If this is increased and there are consumers
older than 0.10.2, the consumers' fetch size must also be increased so
that the they can fetch record batches this large. In the latest
message format version, records are always grouped into batches for
efficiency. In previous message format versions, uncompressed records
are not grouped into batches and this limit only applies to a single
record in that case.This can be set per topic with the topic level
max.message.bytes config.
Default: 1048588 (~1Mb) (Confluent Kafka)
Also refer to the following Stackoverflow answer

Kafka producer and broker compression

If Kafka producer compression is set (e.g. to gzip), and the broker configuration is also set to the same codec, will the broker re-compress any messages from the producer, or recognise that its the same codec and skip and broker-side re-compression?
I'm aware that the broker can be configured to inherit broker codec via the 'producer' setting. However, for our scenario we may have producers (out of our control) who may not set any compression, so we'd like to configure the broker to have default compression enabled, but for those producers that are in our control we'd prefer to use producer compression to save on network bandwidth but also the reduce load on the broker.
Setting topic compression to producer is equivalent to setting it to the same value you use in your producers.
Thus to achieve what you need, you just need to set topic compression to the same algo you use in your producers. The external producers that use the same compression algorithm will work the same as your internal producers, and the rest will trigger a potential decompression/recompression.
This article sums it up nicely:
https://newbedev.com/if-i-set-compression-type-at-topic-level-and-producer-level-which-takes-precedence

What will be the effect of adding compression in kafka broker

After implementation of gzip compression, whether messages stored earlier will aslo get compressed? And while sending messages to consumer whether Message content is changed or kafka internally uncompresses it?
If you turn on Broker side compression, existing messages are unchanged. Compression will apply to only new messages. When consumers fetch the data, it will be automatically decompressed so you don't have to handle it on the consumer side. Just remember, there's a CPU and latency cost by doing this type of compression potentially.