Confluent Cloud Broker and Topic Configuration Settings¶
This topic describes the default Kafka topic and broker configurations in Confluent Cloud. For a complete description of all Kafka broker and topic configurations, see Confluent Platform Configuration Reference.
Important
- Dedicated clusters can be enabled to allow some cluster settings to be changed
- You cannot edit cluster settings on Confluent Cloud on Basic or Standard clusters, but you can edit certain topic configurations after a topic has been created.
- You cannot access internal Kafka topics. For example, the internal topic
__consumer_offsets
is not accessible. Topics that are not accessible do not count toward partition limits or partition billing charges. Topics created by managed Connectors and ksqlDB are accessible. - After a topic has been created, you cannot edit the
cleanup.policy
fromdelete
tocompact
.
Custom topic settings for Basic, Standard, and Dedicated clusters¶
Parameter Name | Default | Editable |
---|---|---|
cleanup.policy | delete | Yes |
compression.type | producer | No |
default.replication.factor | 3 | No |
delete.retention.ms | 86400000 | Yes |
file.delete.delay.ms | 60000 | No |
flush.messages | 9223372036854775807 | No |
flush.ms | 9223372036854775807 | No |
index.interval.bytes | 4096 | No |
log.message.timestamp.type | CreateTime | Yes |
max.compaction.lag.ms | 9223372036854775807 | Yes |
message.downconversion.enable | true | No |
message.format.version | 2.3-IV1 | No |
message.max.bytes | 2097164 | Yes |
message.timestamp.difference.max.ms | 9223372036854775807 | Yes |
message.timestamp.type | CreateTime | Yes |
min.cleanable.dirty.ratio | 0.5 | No |
min.compaction.lag.ms | 0 | Yes |
min.insync.replicas | 2 | Yes |
num.partitions | 6 | Yes, via API |
offsets.retention.minutes | 10080 | No |
preallocate | false | No |
retention.bytes | -1 | Yes |
retention.ms | null | Yes |
segment.index.bytes | 1073741824 | No |
segment.jitter.ms | 0 | No |
segment.ms | 604800000 | Yes |
unclean.leader.election.enable | false | No |
Custom broker / cluster settings for Dedicated clusters only¶
Important
We are gradually upgrading all dedicated clusters in order to make the following settings modifiable. If your clusters haven’t been upgraded yet, you can submit a support request to enable modification of these settings on a per-cluster basis. Your support ticket must include the cluster ID, which you can find on the Cluster Settings page in the Confluent Cloud UI. After support confirms that your cluster has been enabled, you will be able to use the commands below to modify the listed cluster settings. These settings cannot be modified on Basic or Standard clusters.
The following Dedicated cluster settings can be modified using the Kafka CLI:
Enable automatic topic creation (
auto.create.topics.enable
)kafka-configs --bootstrap-server <bootstrap> --command-config config.properties --entity-type brokers --entity-default --alter --add-config auto.create.topics.enable=true
For more information about why the
auto.create.topics.enable
parameter is disabled by default in Confluent Cloud, see this blog post.Restrict allowed SSL cipher suites (
ssl.cipher.suites
)kafka-configs --bootstrap-server <bootstrap> --command-config config.properties --entity-type brokers --entity-default --alter --add-config ssl.cipher.suites=<list>
The valid list of ciphers includes:
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Set the default number of partitions for new topics (
num.partitions
)kafka-configs --bootstrap-server <bootstrap> --config-file <auth-configs> --entity-type brokers --entity-default --alter --add-config num.partitions=<int>
Set the default maximum log compaction time for new topics (
log.cleaner.max.compaction.lag.ms
)kafka-configs --bootstrap-server <bootstrap> --config-file <auth-configs> --entity-type brokers --entity-default --alter --add-config log.cleaner.max.compaction.lag.ms=<int>
Set the default log retention time for new topics (
log.retention.ms
)kafka-configs --bootstrap-server <bootstrap> --config-file <auth-configs> --entity-type brokers --entity-default --alter --add-config log.retention.ms=<int>
Changes to the above config setting are dynamically applied to your Confluent Cloud cluster.