The indices.lifecycle.poll_interval setting controls how frequently the Index Lifecycle Management (ILM) process checks indices to see if they meet the criteria for lifecycle transitions.
- Default value:
10m(10 minutes) - Possible values: Time value (e.g.,
30s,5m,1h) - Recommendation: The default value is suitable for most use cases. Adjust only if you need more frequent or less frequent checks.
This setting determines the interval at which ILM polls indices to check if they're ready for lifecycle transitions. A shorter interval can make ILM more responsive but may increase system load, while a longer interval reduces overhead but may delay policy actions.
Example
To change the poll interval to 5 minutes using the cluster settings API:
PUT _cluster/settings
{
"persistent": {
"indices.lifecycle.poll_interval": "5m"
}
}
This change might be desirable in environments where you need ILM to react more quickly to index conditions, such as in systems with rapid data ingestion and frequent rollovers.
Common Issues
- Setting the interval too low can increase CPU and I/O load, especially in large clusters with many indices.
- Very long intervals may cause delays in policy actions, potentially leading to unexpected index growth or retention issues.
Do's and Don'ts
- Do monitor system resources after changing this setting to ensure it doesn't negatively impact performance.
- Don't set extremely short intervals (e.g., seconds) unless absolutely necessary and thoroughly tested.
- Do consider the trade-off between responsiveness and system load when adjusting this value.
- Don't forget to adjust related timeouts if significantly increasing this interval.
Frequently Asked Questions
Q: How does changing the poll interval affect ILM performance?
A: A shorter interval makes ILM more responsive but can increase system load. A longer interval reduces overhead but may delay policy actions.
Q: Can I set different poll intervals for different indices?
A: No, this is a cluster-wide setting that applies to all indices managed by ILM.
Q: Will changing this setting affect ongoing ILM operations?
A: No, it only affects the frequency of future checks. Ongoing operations will continue as normal.
Q: Is there a minimum recommended value for the poll interval?
A: While there's no hard minimum, values below 1 minute are generally not recommended due to potential performance impacts.
Q: How does this setting interact with the indices.lifecycle.origination_date setting?
A: The poll_interval determines how often ILM checks indices, while origination_date affects when an index is considered to have started its lifecycle. They work independently but both influence when actions are taken on an index.
