OpenSearch/docs/reference/indices/rollover-index.asciidoc

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[[indices-rollover-index]]
== Rollover Index
The rollover index API rolls an alias over to a new index when the existing
index is considered to be too large or too old.
The API accepts a single alias name and a list of `conditions`. The alias
must point to a single index only. If the index satisfies the specified
conditions then a new index is created and the alias is switched to point to
the new alias.
[source,js]
--------------------------------------------------
PUT /logs-000001 <1>
{
"aliases": {
"logs_write": {}
}
}
# Add > 1000 documents to logs-000001
POST /logs_write/_rollover <2>
{
"conditions": {
"max_age": "7d",
"max_docs": 1000
}
}
--------------------------------------------------
// CONSOLE
// TEST[setup:huge_twitter]
// TEST[s/# Add > 1000 documents to logs-000001/POST _reindex?refresh\n{"source":{"index":"twitter"},"dest":{"index":"logs-000001"}}/]
<1> Creates an index called `logs-0000001` with the alias `logs_write`.
<2> If the index pointed to by `logs_write` was created 7 or more days ago, or
contains 1,000 or more documents, then the `logs-000002` index is created
and the `logs_write` alias is updated to point to `logs-000002`.
The above request might return the following response:
[source,js]
--------------------------------------------------
{
"acknowledged": true,
"shards_acknowledged": true,
"old_index": "logs-000001",
"new_index": "logs-000002",
"rolled_over": true, <1>
"dry_run": false, <2>
"conditions": { <3>
"[max_age: 7d]": false,
"[max_docs: 1000]": true
}
}
--------------------------------------------------
// TESTRESPONSE
<1> Whether the index was rolled over.
<2> Whether the rollover was dry run.
<3> The result of each condition.
[float]
=== Naming the new index
If the name of the existing index ends with `-` and a number -- e.g.
`logs-000001` -- then the name of the new index will follow the same pattern,
incrementing the number (`logs-000002`). The number is zero-padded with a length
of 6, regardless of the old index name.
If the old name doesn't match this pattern then you must specify the name for
the new index as follows:
[source,js]
--------------------------------------------------
POST /my_alias/_rollover/my_new_index_name
{
"conditions": {
"max_age": "7d",
"max_docs": 1000
}
}
--------------------------------------------------
// CONSOLE
// TEST[s/^/PUT my_old_index_name\nPUT my_old_index_name\/_alias\/my_alias\n/]
[float]
=== Using date math with the rolllover API
It can be useful to use <<date-math-index-names,date math>> to name the
rollover index according to the date that the index rolled over, e.g.
`logstash-2016.02.03`. The rollover API supports date math, but requires the
index name to end with a dash followed by a number, e.g.
`logstash-2016.02.03-1` which is incremented every time the index is rolled
over. For instance:
[source,js]
--------------------------------------------------
PUT /<logs-{now/d}-1> <1>
{
"aliases": {
"logs_write": {}
}
}
PUT logs_write/log/1
{
"message": "a dummy log"
}
# Wait for a day to pass
POST /logs_write/_rollover <2>
{
"conditions": {
"max_docs": "1"
}
}
--------------------------------------------------
// CONSOLE
// TEST[s/\{now\//{2016.10.31||%2f/]
<1> Creates an index named with today's date (e.g.) `logs-2016.10.31-1`
<2> Rolls over to a new index with today's date, e.g. `logs-2016.10.31-000002` if run immediately, or `logs-2016.11.01-000002` if run after 24 hours
//////////////////////////
[source,js]
--------------------------------------------------
GET _alias
--------------------------------------------------
// CONSOLE
// TEST[continued]
[source,js]
--------------------------------------------------
{
"logs-2016.10.31-000002": {
"aliases": {
"logs_write": {}
}
},
"logs-2016.10.31-1": {
"aliases": {}
}
}
--------------------------------------------------
// TESTRESPONSE
//////////////////////////
These indices can then be referenced as described in the
<<date-math-index-names,date math documentation>>. For example, to search
over indices created in the last three days, you could do the following:
[source,js]
--------------------------------------------------
GET /<logs-{now/d}-*>,<logs-{now/d-1d}-*>,<logs-{now/d-2d}-*>/_search
--------------------------------------------------
// CONSOLE
// TEST[continued]
// TEST[s/now\//now%2f/]
[float]
=== Defining the new index
The settings, mappings, and aliases for the new index are taken from any
matching <<indices-templates,index templates>>. Additionally, you can specify
`settings`, `mappings`, and `aliases` in the body of the request, just like the
<<indices-create-index,create index>> API. Values specified in the request
override any values set in matching index templates. For example, the following
`rollover` request overrides the `index.number_of_shards` setting:
[source,js]
--------------------------------------------------
PUT /logs-000001
{
"aliases": {
"logs_write": {}
}
}
POST /logs_write/_rollover
{
"conditions" : {
"max_age": "7d",
"max_docs": 1000
},
"settings": {
"index.number_of_shards": 2
}
}
--------------------------------------------------
// CONSOLE
[float]
=== Dry run
The rollover API supports `dry_run` mode, where request conditions can be
checked without performing the actual rollover:
[source,js]
--------------------------------------------------
PUT /logs-000001
{
"aliases": {
"logs_write": {}
}
}
POST /logs_write/_rollover?dry_run
{
"conditions" : {
"max_age": "7d",
"max_docs": 1000
}
}
--------------------------------------------------
// CONSOLE
[float]
=== Wait For Active Shards
Because the rollover operation creates a new index to rollover to, the
<<create-index-wait-for-active-shards,`wait_for_active_shards`>> setting on
index creation applies to the rollover action as well.