alias.md

Alias

An index alias is a logical name used to reference one or more indices. Most Elasticsearch APIs accept an index alias in place of an index name.

Add and Remove

To add and remove aliases using elastic4s, we create instances of AliasAction and pass those to an AliasRequest which we can create manually or by the DSL method aliases.

For example, to add a single alias to the beach index.

client.execute {
  aliases(
    addAlias("beaches_alias", "beach")
  )
}

We can perform multiple alias actions in a single request, including removal.

client.execute {
  aliases(
    removeAlias("beaches_alias", "beach"),
    addAlias("mountains_alias", "mountains")
  )
}

Filters

Aliases can also include filters.

client.execute {
  aliases(
    addAlias("metal_beaches", "beaches").filter(prefixQuery("name", "g"))
  )
}

Exists

To check if an alias exists, we can use:

client.execute {
  aliasExists("mountains_alias")
}

Get Aliases

We can retrieve aliases for a given index(es), or we can retrieve indexes for a given alias(es), or combinations therefore.

To lookup aliases used by one or more index:

client.execute {
  getAliases(Seq("mountains", "beaches"), Nil)
}

And to lookup by alias:

client.execute {
  getAliases(Nil, Seq("mountains_alias", "metal_beaches"))
}