[evlapix]

I haven't used this yet, but it seems like it should make updating mappings much easier. See the "using aliases for greater flexibility" section in this article: http://www.elasticsearch.org/blog/changing-mapping-with-zero...

I had to write the scripts to implement this concept myself and it wasn't a quick and easy task. It would had gone along a lot easier if I was able to abstract away some of those queries with a tool like this.

[evantahler]

We use index mappings at TaskRabbit, and it does make things a lot easier. It helps with 0-downtime mapping changes (as you point out), and it also lets us combine large indexes. We segment large data collections by time (ie: events_year_month) which we roll up in an alias. This allows us to delete/add large collections without downtime as well.

What's cool about the elsasticsearch api (and therefore the elasticdump tool) is that with aliases, you can read/write to and from an index just like you can an alias.