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A rolling restart of your ES cluster (keeping it operational while taking nodes offline one at a time) may be needed to upgrade the Elasticsearch version or to perform maintenance on the server itself (such as an OS update or hardware change). Because Elasticsearch wants prefers to keep data fully replicated and evenly balanced, it must be made to pause rebalancing until the rolling restart is donecompletes.
This pausing is done performed through ES settings changes, as recommended by Elasticsearch in the bolded links below. The essential process is this:
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