The http.client_stats.closed_channels.max_age setting in Elasticsearch controls the maximum age of closed HTTP channels to be included in the client statistics. This setting helps manage the memory usage and relevance of the collected HTTP client statistics.
Description
- Default value: 5m (5 minutes)
- Possible values: Time value (e.g., 30s, 2m, 1h)
- Recommendation: Adjust based on your specific monitoring needs and cluster resources
This setting determines how long closed HTTP channels should be kept in memory for statistical purposes. After the specified time has elapsed, the closed channel information is removed from the statistics, helping to maintain relevant and current data while managing memory usage.
Version Information
This setting is available in Elasticsearch 7.7.0 and later versions.
Example
To change the http.client_stats.closed_channels.max_age setting using the cluster settings API:
PUT _cluster/settings
{
"persistent": {
"http.client_stats.closed_channels.max_age": "10m"
}
}
In this example, we're increasing the max age to 10 minutes. This change might be desired if you want to retain closed channel information for a longer period, perhaps for more comprehensive analysis of HTTP client behavior. However, be aware that increasing this value will result in higher memory usage.
Common Issues or Misuses
- Setting the value too high can lead to excessive memory usage, especially in clusters with high HTTP traffic.
- Setting the value too low might result in insufficient data for meaningful analysis of HTTP client behavior.
Do's and Don'ts
Do's:
- Adjust the setting based on your specific monitoring needs and available resources.
- Monitor memory usage when changing this setting, especially when increasing the value.
- Consider the trade-off between data retention and resource usage.
Don'ts:
- Don't set an excessively high value without considering the memory implications.
- Avoid frequent changes to this setting, as it may impact the consistency of your monitoring data.
Frequently Asked Questions
Q: How does this setting affect Elasticsearch performance?
A: This setting primarily affects memory usage. A higher value will retain more information about closed HTTP channels, potentially increasing memory usage, while a lower value will reduce memory usage but may limit the available data for analysis.
Q: Can I disable this feature entirely?
A: While you cannot completely disable HTTP client statistics collection, you can set this value to a very low number (e.g., "1s") to minimize the retention of closed channel information.
Q: How does this setting interact with other HTTP client stats settings?
A: This setting works in conjunction with other HTTP client stats settings to provide a comprehensive view of HTTP client behavior. It specifically focuses on the retention of closed channel information.
Q: Will changing this setting affect existing statistics?
A: Changing this setting will not immediately affect existing statistics, but it will impact the retention of new closed channel information going forward.
Q: How can I monitor the impact of this setting on my cluster?
A: You can monitor memory usage and the size of HTTP client statistics through Elasticsearch's monitoring APIs and tools like Kibana. Pay attention to memory usage trends after changing this setting.
