anchor.diff:  timeouts.
   
   [float]
  +[[docs-reindex-change-name]]
   === Reindex to change the name of a field
   
   `_reindex` can be used to build a copy of an index with renamed fields. Say you
  
positive.code: Elasticsearch can reclaim the space it uses.
  
  `wait_for_active_shards` controls how many copies of a shard must be active
  before proceeding with the reindexing. See <<index-wait-for-active-shards,here>> 
  for details. `timeout` controls how long each write request waits for unavailable
  shards to become available. Both work exactly how they work in the
  <<docs-bulk,Bulk API>>.
  
negative.code: // TESTRESPONSE
  
  Or you can search by `tag` or whatever you want.
  
  
  [float]
  === Reindex daily indices
  
  You can use `_reindex` in combination with <<modules-scripting-painless, Painless>>
   to reindex daily indices to apply a new template to the existing documents.
  
  Assuming you have indices consisting of documents as following:
  
  [source,js]
  ----------------------------------------------------------------
  PUT metricbeat-2016.05.30/beat/1?refresh
  {"system.cpu.idle.pct": 0.908}
  PUT metricbeat-2016.05.31/beat/1?refresh
  {"system.cpu.idle.pct": 0.105}
  ----------------------------------------------------------------
  // CONSOLE
  
  The new template for the `metricbeat-*` indices is already loaded into elasticsearch
  but it applies only to the newly created indices. Painless can be used to reindex
  the existing documents and apply the new template.
  
  The script below extracts the date from the index name and creates a new index
  with `-1` appended. All data from `metricbeat-2016.05.31` will be reindex
  into `metricbeat-2016.05.31-1`.
  
  [source,js]
  ----------------------------------------------------------------
  POST _reindex
  {
    "source": {
      "index": "metricbeat-*"
    },
    "dest": {
      "index": "metricbeat"
    },
    "script": {
      "lang": "painless",
      "inline": "ctx._index = 'metricbeat-' + (ctx._index.substring('metricbeat-'.length(), ctx._index.length())) + '-1'"
    }
  }
  ----------------------------------------------------------------
  // CONSOLE
  // TEST[continued]
  
  All documents from the previous metricbeat indices now can be found in the `*-1` indices.
  
  [source,js]
  ----------------------------------------------------------------
  GET metricbeat-2016.05.30-1/beat/1
  GET metricbeat-2016.05.31-1/beat/1
  ----------------------------------------------------------------
  // CONSOLE
  // TEST[continued]
  
  The previous method can also be used in combination with <<docs-reindex-change-name, change the name of a field>>
  to only load the existing data into the new index, but also rename fields if needed.
  