# Freight Clients for Confluent Cloud [Freight](../../_glossary.md#term-Freight-Kafka-cluster) clients need configurations slightly different than the optimizations for other cluster types. This topic contains several example client configurations for optimizing client performance with Freight clusters. These configurations are designed to help you minimize latency, maximize throughput, meet Freight cluster requirements, and minimize costs. ## Java clients Use these examples for Java clients. ### Producer Requirement: - Disable idempotent producer: `enable.idempotence=false` Recommendations: - Increase linger for larger batches: `linger.ms=100` - Use larger batch size (1MB): `batch.size=1048576` - Increase buffer memory size (500MB): `buffer.memory=524288000` - Disable adaptive partitioning: `partitioner.adaptive.partitioning.enable=false` - Increase metadata refresh rate: `metadata.max.age.ms=60000` ### Consumer - Set max fetch bytes: `max.partition.fetch.bytes=8388608` - Increase metadata refresh rate: `metadata.max.age.ms=60000` ## librdkafka-based clients Use these examples for librdkafka-based clients. ### Producer Requirement: - Disable idempotent producer: `enable.idempotence=false` Recommendations: - Increase linger for larger batches: `linger.ms=100` - Increase in-flight request: `max.in.flight.requests.per.connection=5` ### Consumer - Set max fetch bytes: `max.partition.fetch.bytes=8388608` ## Zone alignment Freight clusters support producer and consumer zone alignment to minimize cross-zone network charges. To ensure Kafka clients produce to and consume from Confluent Cloud endpoints within the same zone, you must specify a zone identifier as part of the client identifier settings. Zone identifiers must match the zone of the network to which the client connects. You can find zone identifiers in the Cloud Console as well as in the Confluent Cloud Networking API. For more information, see [Networks-(networkingv1)](https://docs.confluent.io/cloud/current/ccloud/networks-networking-v-1/). ### Specify zone identifiers This section shows you how to use the `client.id` string to specify zone identifiers. Considerations: - The Availability Zone ID in your client configuration must match exactly the Availability Zone ID in the Confluent Cloud Console - Availability Zone ID (`use2-az1`) is different from an Availability Zone name (`us-east-1a`) To specify zone identifiers, include a `confluent_zone` parameter as part of your `client.id` string. Add the `confluent_zone` parameter as a prefix to your existing client identifier separated by a comma. ```none client.id=confluent_zone=,existing-client-id ``` For example, if your existing client identifier is `producer-1` and the zone identifier is `use2-az1`, your client identifier would look like this: ```none client.id=confluent_zone=use2-az1,producer-1 ``` ### Availability Zone IDs vs. Availability Zone names Use the Availability Zone ID (`use2-az1`) to identify your Availability Zone and not the Availability Zone name (`us-east-1a`). AWS generates Availability Zone names randomly for each AWS account. Availability Zone ID are constant across all accounts. For more information, see [Availability Zone IDs for your AWS resources](https://docs.aws.amazon.com/ram/latest/userguide/working-with-az-ids.html). ### Follower fetching vs. zone alignment For consumer traffic in AWS, Freight clusters support follower fetching. For more information, see [Optimize Egress Costs with Follower Fetching on Confluent Cloud in AWS](../../networking/fetch-from-follower.md#fetch-from-follower-aws). Follower fetching requires a similar client configuration for identifying the zone to which a consumer belongs. If you configure a consumer for both follower fetching and zone alignment, the follower fetching configuration takes precedence. Note that `client.rack` must be configured for consumers. ## Related content - [Kafka Cluster Types in Confluent Cloud](../../clusters/cluster-types.md#cloud-cluster-types) - [Freight cluster considerations](../../clusters/cluster-types.md#freight-limitations)