Recommendations for Client Usage

Ensure that the owner thread does not exit abnormally. Otherwise, the client may fail to initiate consumption requests and the consumption will be blocked.
Ensure that the commit operation is performed after messages are processed. This is to avoid the failure of processing service messages and the failure to retrieve the message that fails to be processed.
A consumer cannot frequently join or leave a group. Otherwise, the consumer will frequently perform rebalancing, which blocks consumption.
The number of consumers cannot be greater than the number of partitions in the topic. Otherwise, some consumers may fail to poll for messages.
Ensure that the consumer polls at regular intervals to keep sending heartbeats to the server. If the consumer stops sending heartbeats for long enough, the consumer session will time out and the consumer will be considered to have stopped. This will also block consumption.
Ensure that there is a limitation on the size of messages buffered locally to avoid an out-of-memory (OOM) situation.
The timeout interval of the consumer session is set to 30 seconds, and session.timeout.ms is set to 30000. This prevents the consumer from performing rebalance due to frequent timeout. Frequent timeout will block consumption.
ROMA Connect may consume repeated messages. The service side must ensure the idempotency of message processing.
Always close the consumer before exiting. Otherwise, consumers in the same group may block the session.timeout.ms time.

Recommended topic configurations: Use 3 replicas, enable synchronous replication, and set the minimum number of in-sync replicas to 2. The number of in-sync replicas cannot be the same as the number of replicas of the topic. Otherwise, if one replica is unavailable, messages cannot be produced.
You can enable or disable automatic topic creation. If it is enabled, a topic will be automatically created with 3 partitions and 3 replicas when a message is created in or retrieved from a topic that does not exist.
The recommended maximum number of partitions for a topic is 20.
Each topic can have 3 replicas (the number of replicas cannot be modified once configured).

Maximum number of connections: 3000
Maximum size of a message: 10 MB
Access ROMA Connect using SASL_SSL. Ensure that your DNS service is capable of resolving an IP address to a domain name. Alternatively, map all ROMA Connect broker IP addresses to host names in the hosts file. Prevent Kafka clients from performing reverse resolution. Otherwise, connections may fail to be established.
Apply for a disk space size that is more than twice the size of service data multiplied by the number of replicas. In other words, keep 50% of the disk space idle.
Avoid frequent full GC in JVM. Otherwise, message production and consumption will be blocked.

If both SASL_SSL and intra-VPC plaintext access are enabled for MQS of the ROMA Connect instance, the SASL mode cannot be used for connecting to MQS topics in the VPC.
If the SASL mode is used for connecting to MQS topics, you are advised to configure the mapping between the host and IP address in the /etc/hosts file on the host where the client is located. Otherwise, network delay will occur.
Set the IP address to the connection address of MQS and set the host to the name of each instance host. Ensure that the name of each host is unique. Example:

10.10.10.11 host01

10.10.10.12 host02

10.10.10.13 host03