The http.tcp.receive_buffer_size setting in Elasticsearch controls the size of the TCP receive buffer for HTTP traffic. This setting affects the amount of memory allocated for incoming HTTP connections, potentially impacting network performance and throughput.
Description
- Default value: Not explicitly set (uses OS default)
- Possible values: Size in bytes or size notation (e.g., "10kb", "2mb")
- Recommendations: Generally, it's best to leave this setting at its default unless you have specific performance requirements or are experiencing network-related issues.
This setting is available in all recent versions of Elasticsearch.
Example
To change the http.tcp.receive_buffer_size setting using the cluster settings API:
PUT _cluster/settings
{
"persistent": {
"http.tcp.receive_buffer_size": "2mb"
}
}
You might want to increase this value if you're dealing with high-volume HTTP traffic and have available system memory. Increasing the buffer size can potentially improve network performance by allowing more data to be buffered before processing.
Common Issues
- Setting this value too high can lead to excessive memory usage, especially on systems with many concurrent connections.
- Very large buffer sizes may not always translate to better performance and can sometimes lead to increased latency.
Do's and Don'ts
Do:
- Monitor network performance and adjust this setting only if necessary.
- Consider the available system resources when modifying this setting.
- Test changes in a non-production environment before applying to production.
Don't:
- Arbitrarily increase this value without understanding the implications.
- Ignore other network-related settings when tuning this one.
- Set this value higher than your available system memory can support.
Frequently Asked Questions
Q: How does the http.tcp.receive_buffer_size setting affect Elasticsearch performance?
A: This setting can impact the network performance of HTTP connections to Elasticsearch. A larger buffer size may improve throughput for high-volume traffic but can also increase memory usage.
Q: Should I always set a custom value for http.tcp.receive_buffer_size?
A: No, in most cases, the default OS-provided value is sufficient. Only consider changing this if you have specific performance requirements or are experiencing network-related issues.
Q: Can increasing http.tcp.receive_buffer_size solve all network performance issues?
A: No, while it can help in some scenarios, network performance depends on many factors. It's important to consider other settings and potential bottlenecks as well.
Q: How can I determine the optimal value for http.tcp.receive_buffer_size?
A: The optimal value depends on your specific use case, available system resources, and network conditions. It's best to start with the default and gradually increase while monitoring performance and resource usage.
Q: Is it safe to change http.tcp.receive_buffer_size in a production environment?
A: While it's generally safe, it's always recommended to test changes in a non-production environment first. Sudden large changes to this setting could impact system stability or performance.
