- What scaling accomplishes
- Manual scaling
- Introduction to autoscaling
- Scheduled autoscaling
- Search-rate autoscaling
- Changes in node counts when switching approaches
Managed Search supports both manual scaling of the number of Solr nodes in a Managed Search cluster and autoscaling, for which Managed Search scales the number of Solr nodes automatically based on specific conditions.
What scaling accomplishes
Scaling the number of Solr nodes (that is, increasing or decreasing the number of Solr nodes) accomplishes this:
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Scaling up – Handle higher search-request loads by adding Solr nodes. This keeps search-request latencies at a desirable level, instead of letting them increase.
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Scaling down – When search-request loads decrease, free up resources that aren’t needed to provide desirable search-request latencies.
Manual scaling
Scale Solr nodes in Managed Search clusters to meet the search needs of your organization. You can specify these scale-related attributes of a cluster when you create it, and when you manually scale the cluster later.
Attribute | Description | ||
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Solr node type. Different Solr node types make available different numbers of CPUs and different amounts of memory. Different node types also have different default amounts of disk storage, if you create a cluster without specifying |
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Number of Solr nodes. This top-level
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Amount of disk space to use per Solr node, in gigabytes.
|
Note
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During both manual scaling and autoscaling, Managed Search ensures that no data is lost. |
Node type (nodeType
) and storage size (storageSizeGB
) settings apply both when autoscaling is enabled and disabled.
Read about how to manually scale a Solr cluster.
Introduction to autoscaling
Enable autoscaling to ensure that your Managed Search clusters handle varying levels of searching demand. Autoscaling automatically increases and decreases the number of Solr nodes in a Managed Search cluster.
Managed Search supports two types of autoscaling.
Type | Description | ||
---|---|---|---|
Scheduled |
Summary:
Managed Search automatically scales the number of Solr nodes in a cluster to specified numbers at specified times on specified days. If no time is specified in a schedule entry, then the default time For example, this schedule scales the number of nodes up to
Scale-up: When a scheduled time for autoscaling arrives and the number of Solr nodes specified in the schedule entry exceeds the current number of Solr nodes Scale-down: When a scheduled time for autoscaling arrives and the number of Solr nodes specified in the schedule entry is fewer than the current number of Solr nodes |
||
Search rate |
Summary:
Managed Search compares the actual average search rate across Solr nodes to the target average search rate (
Scale-up: When the average search rate equals or exceeds the target search rate Scale-down: When the average search rate falls below the target search rate |
Note
|
During both manual scaling and autoscaling, Managed Search ensures that no data is lost. |
Scheduled autoscaling
Scheduled autoscaling scales the number of Solr nodes in a Managed Search cluster based on the day of the week and the time of day. For example, the level of demand for searching might increase at the end of the work day and then decrease at night.
This diagram illustrates the simple case that is used as an example in Introduction to autoscaling: autoscaling up (to 10 nodes) for the work week and down (to 5 nodes) for the weekend.
A schedule contains two or more schedule entries. Each schedule entry gives the time of the scale transition and the number of Solr nodes to use after the transition. See Attributes for scheduled autoscaling for more information.
Note
|
The autoscaling schedule applies every week, until you change the schedule or disable autoscaling. |
Search-rate autoscaling
Search-rate autoscaling scales the number of Solr nodes in a Managed Search cluster up and down based on comparisons of the actual average of search rates for all nodes and a target average search rate for all nodes:
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Up – When search load increases, Managed Search increases the number of Solr nodes to better meet the demand.
When the average of the trailing one-minute search rates across current Solr nodes equals or exceeds the target search rate, Managed Search increases the number of nodes by one, until the maximum number of nodes
maxNodes
is reached. -
Down – When search load decreases, Managed Search decreases the number of Solr nodes to reduce resource consumption.
When the average of the trailing one-minute search rates across current Solr nodes is less than the target search rate, Managed Search decreases the number of nodes by one, until the minimum number of nodes
minNodes
is reached.
This diagram illustrates search-rate autoscaling. "QPN" is queries per node per time interval, that is, the average search rate across nodes.
Search-rate autoscaling keeps the actual average search rate closer to the target average search rate.
Changes in node counts when switching approaches
These rules apply when enabling and disabling autoscaling, and when switching between different types of autoscaling:
Enabling autoscaling:
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When you enable scheduled or search-rate autoscaling, the node count initially doesn’t change.
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With scheduled autoscaling, the first adjustment in node count occurs when the first transition time in the schedule arrives.
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With search-rate autoscaling, the first adjustment in node count occurs when the search-rate comparison algorithm determines that an adjustment is needed.
Switching between autoscaling types:
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When you switch between scheduled and search-rate autoscaling, the node count doesn’t change.
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When you switch to scheduled autoscaling, the first adjustment in node count occurs when the first transition time in the schedule arrives.
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When you switch to search-rate autoscaling, the first adjustment in node count occurs when the search-rate comparison algorithm determines that an adjustment is needed.
Disabling autoscaling:
-
When you disable autoscaling, the node count doesn’t change, with one exception: when you disable autoscaling and specify a
nodeCount
in the request.