This is the process for in-place upgrades of Elasticsearch (ES), using an existing Search feed and index data.
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ImportantType Ctrl-C once, when the upgrade script is stuck in retrying status checks and proceed to the next node after the script finishes if the cluster loses master during the upgrade process and does not recover. Review The nodes elect the master and recover once all nodes have started on Elasticsearch 7.5.2. Health status goes yellow then eventually green. Re-enable shard allocation, otherwise |
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It fixes
/etc/sysconfig/elasticsearchto the correct ES6 version (the same as ES7).It increases the
systemdtimeout in/etc/systemd/system/elasticsearch.service.d/override.conf(see github.com/elastic/elasticsearch/issues/60140)A prompt to continue with the yum upgrade to 7.5.2 appears after refreshing the config files for Elasticsearch 6.
It disables shard allocation and does a POST synced-flush for safer rolling upgrades.
Info title Important Disabling shard allocation or sync-flush can fail to contact the node, but do not proceed to upgrade the next node until the cluster health is green again.
It uninstalls the Prometheus Exporter plugin if it exists.
It shells out to yum to install the Elasticsearch 7 RPM in the current directory or from artifacts.elastic.co, if unavailable.
Warning Internet access is expected for the upgrade. Verify the Elasticsearch RPM is in the current directory if access is unavailable.
It updates elasticsearch.yml for version 7 compatibility, including
discovery.initial_master_nodesinstead ofdiscovery.zen.unicast.hosts, andjvm.options.It starts the upgraded Elasticsearch 7 and waits for it to be ready.
The cluster re-enables shard allocation and prompts to repeat these two steps on the next node if the cluster health is green or yellow.