TCP packets sitting at producer for ~270ms before flushing out

[vpremk]

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Description

We noticed a significant delay in librdbkafka c++ as compared to Python producer. On analysis of tcpdump, we see TCP packets sitting at producer for ~270ms before flushing out

How to reproduce

librdkafka-2.2.2 used for our impletemenation

IMPORTANT: Always try to reproduce the issue on the latest released version (see https://github.com/confluentinc/librdkafka/releases), if it can't be reproduced on the latest version the issue has been fixed.

Checklist

IMPORTANT: We will close issues where the checklist has not been completed.

Please provide the following information:

• librdkafka version (release number or git tag): <REPLACE with e.g., v0.10.5 or a git sha. NOT "latest" or "current">
• Apache Kafka version: <REPLACE with e.g., 0.10.2.3>
• librdkafka client configuration: <REPLACE with e.g., message.timeout.ms=123, auto.reset.offset=earliest, ..>
• Operating system: <REPLACE with e.g., Centos 5 (x64)>
• Provide logs (with debug=.. as necessary) from librdkafka
• Provide broker log excerpts
• Critical issue