Error Message "Trying to create too many scroll contexts" Is Displayed When the update-by-query Command Is Executed

Symptom

When I run the update-by-query command in an Elasticsearch cluster, the error message "Trying to create too many scroll contexts." is displayed. The specific error information is as follows:

{"error":{"root_cause":[{"type":"exception","reason":"Trying to create too many scroll contexts. Must be less than or equal to: [100000]. This limit can be set by changing the [search.max_open_scroll_context] setting."},{"type":"exception","reason":"Trying to create too many scroll contexts. Must be less than or equal to: [100000]. ......

Possible Causes

Each time a cluster calls the scroll creation API, a scroll context is created. When the number of scroll contexts reaches the preset threshold, no more scrolls can be created.

Procedure

GET /_nodes/stats/indices/search

When the value reaches the upper limiter, use either of the following methods to solve the problem.

• Method 1: Delete unnecessary scrolls to release the storage space of scroll contexts.

  DELETE /_search/scroll
  {  "scroll_id" : "DXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAD4WYm9laVYtZndUQlNsdDcwakFMNjU1QQ=="}

• Method 2: Change the value of search.max_open_scroll_context to increase the storage space for scroll contexts.

  PUT /_cluster/settings
  {
  	"persistent" : {
  		"search.max_open_scroll_context": 2012345678
  	},
  
  	"transient": {
  		"search.max_open_scroll_context": 2012345678
  	}
  }