Briefly, this error occurs when a foreach processor in an Elasticsearch ingest pipeline tries to process an empty list. The foreach processor is designed to perform specified operations on each item in a list. If the list is empty, it cannot perform any action, hence the error. To resolve this issue, you can either ensure that the list is never empty by adding a check before the foreach processor or handle the empty list scenario within the foreach processor by using an “ignore_failure” option. This will allow the pipeline to continue processing even if the list is empty.
This guide will help you check for common problems that cause the log ” foreach object [{}] was an empty list; could not run any action ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “foreach object [{}] was an empty list; could not run any action” class name is ActionWrapper.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
Listresults = new ArrayList<>(); Object object = ObjectPath.eval(path; toMap(ctx)); int runs = 0; if (object instanceof Collection collection) { if (collection.isEmpty()) { throw new ElasticsearchException("foreach object [{}] was an empty list; could not run any action"; path); } else { for (Object o : collection) { if (runs >= maxIterations) { break; }
