Full cluster restart upgradeedit

A full cluster restart upgrade requires that you shut all nodes in the cluster down, upgrade them, and restart the cluster. A full cluster restart was required when upgrading to major versions prior to 6.x. Elasticsearch 6.x supports rolling upgrades from Elasticsearch 5.6. Upgrading to 6.x from earlier versions requires a full cluster restart. See the Upgrade paths table to verify the type of upgrade you need to perform.

To perform a full cluster restart upgrade:

  1. Disable shard allocation.

    When you shut down a node, the allocation process waits for one minute before starting to replicate the shards on that node to other nodes in the cluster, causing a lot of wasted I/O. You can avoid racing the clock by disabling allocation before shutting down the node:

    PUT _cluster/settings
    {
      "persistent": {
        "cluster.routing.allocation.enable": "none"
      }
    }
  2. Stop indexing and perform a synced flush.

    Performing a synced-flush speeds up shard recovery.

    POST _flush/synced

    When you perform a synced flush, check the response to make sure there are no failures. Synced flush operations that fail due to pending indexing operations are listed in the response body, although the request itself still returns a 200 OK status. If there are failures, reissue the request.

  3. Shutdown all nodes.

    • If you are running Elasticsearch with systemd:

      sudo systemctl stop elasticsearch.service
    • If you are running Elasticsearch with SysV init:

      sudo -i service elasticsearch stop
    • If you are running Elasticsearch as a daemon:

      kill $(cat pid)
  4. Upgrade all nodes.

    To upgrade using a Debian or RPM package:

    • Use rpm or dpkg to install the new package. All files are installed in the appropriate location for the operating system and Elasticsearch config files are not overwritten.

    To upgrade using a zip or compressed tarball:

    1. Extract the zip or tarball to a new directory. This is critical if you are not using external config and data directories.
    2. Set the ES_PATH_CONF environment variable to specify the location of your external config directory and jvm.options file. If you are not using an external config directory, copy your old configuration over to the new installation.
    3. Set path.data in config/elasticsearch.yml to point to your external data directory. If you are not using an external data directory, copy your old data directory over to the new installation.
    4. Set path.logs in config/elasticsearch.yml to point to the location where you want to store your logs. If you do not specify this setting, logs are stored in the directory you extracted the archive to.
    Tip

    When you extract the zip or tarball packages, the elasticsearch-n.n.n directory contains the Elasticsearh config, data, logs and plugins directories.

    We recommend moving these directories out of the Elasticsearch directory so that there is no chance of deleting them when you upgrade Elasticsearch. To specify the new locations, use the ES_PATH_CONF environment variable and the path.data and path.logs settings. For more information, see Important Elasticsearch configuration.

    The Debian and RPM packages place these directories in the appropriate place for each operating system. In production, we recommend installing using the deb or rpm package.

  5. Upgrade any plugins.

    Use the elasticsearch-plugin script to install the upgraded version of each installed Elasticsearch plugin. All plugins must be upgraded when you upgrade a node.

  6. Start each upgraded node.

    If you have dedicated master nodes, start them first and wait for them to form a cluster and elect a master before proceeding with your data nodes. You can check progress by looking at the logs.

    As soon as the minimum number of master-eligible nodes have discovered each other, they form a cluster and elect a master. At that point, you can use _cat/health and _cat/nodes to monitor nodes joining the cluster:

    GET _cat/health
    
    GET _cat/nodes

    The status column returned by _cat/health shows the health of each node in the cluster: red, yellow, or green.

  7. Wait for all nodes to join the cluster and report a status of yellow.

    When a node joins the cluster, it begins to recover any primary shards that are stored locally. The _cat/health API initially reports a status of red, indicating that not all primary shards have been allocated.

    Once a node recovers its local shards, the cluster status switches to yellow, indicating that all primary shards have been recovered, but not all replica shards are allocated. This is to be expected because you have not yet reenabled allocation. Delaying the allocation of replicas until all nodes are yellow allows the master to allocate replicas to nodes that already have local shard copies.

  8. Reenable allocation.

    When all nodes have joined the cluster and recovered their primary shards, reenable allocation.

    PUT _cluster/settings
    {
      "persistent": {
        "cluster.routing.allocation.enable": "all"
      }
    }

    Once allocation is reenabled, the cluster starts allocating replica shards to the data nodes. At this point it is safe to resume indexing and searching, but your cluster will recover more quickly if you can wait until all primary and replica shards have been successfully allocated and the status of all nodes is green.

    You can monitor progress with the _cat/health and _cat/recovery APIs:

    GET _cat/health
    
    GET _cat/recovery