55 lines
1.6 KiB
Plaintext
55 lines
1.6 KiB
Plaintext
[role="xpack"]
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[[ilm-downsample]]
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=== Downsample
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Phases allowed: hot, warm, cold.
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Aggregates a time series (TSDS) index and stores
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pre-computed statistical summaries (`min`, `max`, `sum`, `value_count` and
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`avg`) for each metric field grouped by a configured time interval. For example,
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a TSDS index that contains metrics sampled every 10 seconds can be downsampled
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to an hourly index. All documents within an hour interval are summarized and
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stored as a single document and stored in the downsample index.
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This action corresponds to the <<indices-downsample-data-stream,downsample API>>.
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The name of the resulting downsample index is
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`downsample-<original-index-name>-<random-uuid>`. If {ilm-init} performs the
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`downsample` action on a backing index for a data stream, the downsample index
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becomes a backing index for the same stream and the source index is deleted.
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To use the `downsample` action in the `hot` phase, the `rollover` action *must*
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be present. If no rollover action is configured, {ilm-init} will reject the
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policy.
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[role="child_attributes"]
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[[ilm-downsample-options]]
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==== Options
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`fixed_interval`:: (Required, string) The
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<<rollup-understanding-group-intervals,fixed time interval>> into which the data
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will be downsampled.
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[[ilm-downsample-ex]]
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==== Example
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[source,console]
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----
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PUT _ilm/policy/datastream_policy
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{
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"policy": {
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"phases": {
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"hot": {
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"actions": {
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"rollover": {
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"max_docs": 1
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},
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"downsample": {
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"fixed_interval": "1h"
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}
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}
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}
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}
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}
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}
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---- |