a version associated with each request, and having it associated with the stream when (de)serializing, can allow us in the future to better support cross version communication
The types exists api checks whether one or more types exists in one or more indices.
## Example usage
curl -XHEAD 'localhost:9200/twitter/tweet'
## Options
* `index` - One or more indices. Either specified as query string parameter or in the uri path.
* `type` - One or more types. Either specified as query string parameter or in the uri path.
* `ignore_missing` - Determines what type of indices to exclude from a request. The option can have the following values: `none` or `missing`.
Closes#2273
If has_parent, has_child or top_children are executed incorrectly then a better exception is thrown. This gives a better error description when one of these queries or filters is being used in count api.
Closes#2261
When setting cluster.routing.allocation.disable_allocation, it causes new indices primary shards to not be allocated. By default, new indices created should allow to, at the very least, allocate primary shards so they become operations. A new setting, cluster.routing.allocation.disable_new_allocation, allows to also disable "new" allocations.
closes#2258.
Here is a short example of how a simple reroute API call:
curl -XPOST 'localhost:9200/_cluster/reroute' -d '{
"commands" : [
{"move" : {"index" : "test", "shard" : 0, "from_node" : "node1", "to_node" : "node2"}},
{"allocate" : {"index" : "test", "shard" : 1, "node" : "node3"}}
]
}'
An importnat aspect to remember is the fact that once when an allocation occurs, the cluster will aim at rebalancing its state back to an even state. For example, if the allocation includes moving a shard from `node1` to `node2`, in an "even" state, then another shard will be moved from `node2` to `node1` to even things out.
The cluster can be set to disable allocations, which means that only the explicitl allocations will be performed. Obviously, only once all commands has been applied, the cluster will aim to be rebalance its state.
Anohter option is to run the commands in "dry_run" (as a URI flag, or in the request body). This will cause the commands to apply to the current cluster state, and reutrn the resulting cluster after the comamnds (and rebalancing) has been applied.
The commands supporterd are:
* `move`: Move a started shard from one node to anotehr node. Accepts `index` and `shard` for index name and shard number, `from_node` for the node to move the shard "from", and `to_node` for the node to move the shard to.
* `cancel`: Cancel allocation of a shard (or recovery). Accepts `index` and `shard` for index name and shar number, and `node` for the node to cancel the shard allocation on.
* `allocate`: Allocate an unassigned shard to a node. Accepts the `index` and `shard` for index name and shard number, and `node` to allocate the shard to. It also accepts `allow_primary` flag to explciitly specify that it is allowed to explciitly allocate a primary shard (might result in data loss).
closes#2256
The `has_parent` filter accepts a query and a parent type. The query is executed in the parent document space, which is specified by the parent type. This filter return child documents which associated parents have matched. For the rest `has_parent` filter has the same options and works in the same manner as the `has_child` filter.
This is an experimental filter.
Filter example
###################
```
{
"has_parent" : {
"parent_type" : "blog"
"query" : {
"term" : {
"tag" : "something"
}
}
}
}
```
The `parent_type` field name can also be abbreviated to `type`.
Memory considerations
###############
With the current implementation, all _id values are loaded to memory (heap) in order to support fast lookups, so make sure there is enough mem for it.
This issue originates from issue #792
add support for internal custom allocation commands, including allocation, move, and cancel (shard).
also, fix#2242, which causes the cluster state to be in inconsistent state when a shard being the source of relocation is failed
Shay Banon
Chris Male
Martijn van Groningen
Chris Male
Karel Minarik
Henrik Lindström