Cancel after time interval clarification

OpenSearch
1

Currently deployed: OpenSearch v2.3

Configuration clarification: To ensure a clear understanding of our global search configuration for a given cluster, I want to clarify that the following is correctly stated:

  • The search.cancel_after_time_interval (which defaults to 300s) configures at the shard level termination of a query after 300s if a query has not yet completed; with regard to the search.low_level_cancellation default of true.

  • The search.default_search_timeout configures at the shard level the maximum time to wait for a query to complete before returning a 408 request timeout to the coordinating node; without regard to the search.cancel_after_time_interval setting. As such, if the search.default_search_timeout is configured to be a positive value (instead of the default of -1), it should be a value less than the search.cancel_after_time_interval.

  • The search.keep_alive_interval is the interval at which the coordinating node will send a TCP keep alive to a shard/data node while the search.default_keep_alive and search.max_keep_alive are configured at the shard level/data node level.

  • The search.max_keep_alive global value overrides any keep alive setting that may be included in the query.

I appreciate any clarifications you can provide. The documentation is somewhat helpful, but I haven’t found a lot of straight forward detail specific to the settings above. I’m making some assumptions and I have run into trouble making assumptions in the past. :joy:

Thank you.

Max

2

Hey @maxfriz

Where in the doc’s did you see this and is it posible to link it? They all look like a search/connection time inverval, meaning “if nothing was found stop”

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3

The reference to this specific parameter is found in the API documentation and the API lightly references the cluster setting. This can be found on this page:
OpenSearch Search API

We have an operational OpenSearch cluster that returns the details of these settings with this command:

GET /_cluster/settings?include_defaults=true

While I won’t provide links to Elasticsearch documentation in this forum, these settings can be found in Elasticsearch documentation as well.

4

Hey @maxfriz

I had to do a little research and try to find some documentation; it’s been a while.

So, it looks like shard level setting/search query.
For example, large queries take too much time you may need to increase the settings.

search.cancel_after_time_interval && search.default_search_timeout

I found this and they show a good explanation.

As for

search.keep_alive_interval && search.max_keep_alive

These two, which I think configure the TCP_KEEPINTVL option for nodes, which determines the time in seconds between sending TCP keepalive probes. Defaults to -1, which means to use the system default.

That is all I know about those, perhaps someone else will jump in.

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