AWS autoscaling documentation change
Summary
Updated terminology from 'Auto Scaling group' to 'Amazon EC2 Auto Scaling group' throughout the document for branding consistency
Security assessment
The changes are purely terminological updates replacing 'Auto Scaling group' with 'Amazon EC2 Auto Scaling group'. There are no modifications to security configurations, vulnerability disclosures, or security feature descriptions. The content about scaling policies, warmup periods, and capacity calculations remains functionally identical.
Diff
diff --git a/autoscaling/ec2/userguide/as-scaling-simple-step.md b/autoscaling/ec2/userguide/as-scaling-simple-step.md index 6e36ff539..2726b043c 100644 --- a//autoscaling/ec2/userguide/as-scaling-simple-step.md +++ b//autoscaling/ec2/userguide/as-scaling-simple-step.md @@ -9 +9 @@ How step scaling policies workStep adjustments for step scalingScaling adjustmen -Step scaling and simple scaling policies scale the capacity of your Auto Scaling group in predefined increments based on CloudWatch alarms. You can define separate scaling policies to handle scaling out (increasing capacity) and scaling in (decreasing capacity) when an alarm threshold is breached. +Step scaling and simple scaling policies scale the capacity of your Amazon EC2 Auto Scaling group in predefined increments based on CloudWatch alarms. You can define separate scaling policies to handle scaling out (increasing capacity) and scaling in (decreasing capacity) when an alarm threshold is breached. @@ -11 +11 @@ Step scaling and simple scaling policies scale the capacity of your Auto Scaling -Auto Scaling group capacity is measured in terms of instances or capacity units if you are using [instance weights](./ec2-auto-scaling-mixed-instances-groups-instance-weighting.html). Also, there is a difference between desired capacity and current capacity. +Amazon EC2 Auto Scaling group capacity is measured in terms of instances or capacity units if you are using [instance weights](./ec2-auto-scaling-mixed-instances-groups-instance-weighting.html). Also, there is a difference between desired capacity and current capacity. @@ -47 +47 @@ We strongly recommend that you use target tracking scaling policies to scale on -To use step scaling, you first create a CloudWatch alarm that monitors a metric for your Auto Scaling group. Define the metric, threshold value, and number of evaluation periods that determine an alarm breach. Then, create a step scaling policy that defines how to scale your group when the alarm threshold is breached. You can use a percentage of the current capacity of your Auto Scaling group or capacity units for the scaling adjustment type. For more information, see Scaling adjustment types. +To use step scaling, you first create a CloudWatch alarm that monitors a metric for your Amazon EC2 Auto Scaling group. Define the metric, threshold value, and number of evaluation periods that determine an alarm breach. Then, create a step scaling policy that defines how to scale your group when the alarm threshold is breached. You can use a percentage of the current capacity of your Amazon EC2 Auto Scaling group or capacity units for the scaling adjustment type. For more information, see Scaling adjustment types. @@ -62 +62 @@ When the alarm threshold is breached for the specified number of evaluation peri -Each instance has a warmup period to prevent scaling activities from being too reactive to changes that occur over short periods of time. You can optionally configure the warmup period for your scaling policy. However, we recommend using the default instance warmup to make it easier to update all scaling policies when the warmup time changes. For more information, see [Set the default instance warmup for an Auto Scaling group](./ec2-auto-scaling-default-instance-warmup.html). +Each instance has a warmup period to prevent scaling activities from being too reactive to changes that occur over short periods of time. You can optionally configure the warmup period for your scaling policy. However, we recommend using the default instance warmup to make it easier to update all scaling policies when the warmup time changes. For more information, see [Set the default instance warmup for an Amazon EC2 Auto Scaling group](./ec2-auto-scaling-default-instance-warmup.html). @@ -105 +105 @@ This creates the following scaling configuration. -Now, let's say that you use this scaling configuration on an Auto Scaling group that has both a current capacity and a desired capacity of 10. The following points summarize the behavior of the scaling configuration in relation to the desired and current capacity of the group: +Now, let's say that you use this scaling configuration on an Amazon EC2 Auto Scaling group that has both a current capacity and a desired capacity of 10. The following points summarize the behavior of the scaling configuration in relation to the desired and current capacity of the group: @@ -135 +135 @@ When you specify the step adjustments for your scaling policy, note the followin -You can define a scaling policy that performs the optimal scaling action, based on the scaling adjustment type that you choose. You can specify the adjustment type as a percentage of the current capacity of your Auto Scaling group, or in capacity units. Normally a capacity unit means one instance, unless you are using the instance weights feature. +You can define a scaling policy that performs the optimal scaling action, based on the scaling adjustment type that you choose. You can specify the adjustment type as a percentage of the current capacity of your Amazon EC2 Auto Scaling group, or in capacity units. Normally a capacity unit means one instance, unless you are using the instance weights feature. @@ -162 +162 @@ Show moreShow less -With `PercentChangeInCapacity`, you can also specify the minimum number of instances to scale using the `MinAdjustmentMagnitude` parameter. For example, suppose that you create a policy that adds 25 percent and you specify a minimum increment of 2 instances. If you have an Auto Scaling group with 4 instances and the scaling policy is executed, 25 percent of 4 is 1 instance. However, because you specified a minimum increment of 2, there are 2 instances added. +With `PercentChangeInCapacity`, you can also specify the minimum number of instances to scale using the `MinAdjustmentMagnitude` parameter. For example, suppose that you create a policy that adds 25 percent and you specify a minimum increment of 2 instances. If you have an Amazon EC2 Auto Scaling group with 4 instances and the scaling policy is executed, 25 percent of 4 is 1 instance. However, because you specified a minimum increment of 2, there are 2 instances added. @@ -166 +166 @@ When you use [instance weights](./ec2-auto-scaling-mixed-instances-groups-instan -If you use instance weights, keep in mind that the current capacity of your Auto Scaling group can exceed the desired capacity as needed. If your absolute number to decrement, or the amount that the percentage says to decrement, is less than the difference between current and desired capacity, no scaling action is taken. You must take these behaviors into account when you look at the outcome of a scaling policy when a threshold alarm is in breach. For example, suppose that the desired capacity is 30 and the current capacity is 32. When the alarm is in breach, if the scaling policy decrements the desired capacity by 1, then no scaling action is taken. +If you use instance weights, keep in mind that the current capacity of your Amazon EC2 Auto Scaling group can exceed the desired capacity as needed. If your absolute number to decrement, or the amount that the percentage says to decrement, is less than the difference between current and desired capacity, no scaling action is taken. You must take these behaviors into account when you look at the outcome of a scaling policy when a threshold alarm is in breach. For example, suppose that the desired capacity is 30 and the current capacity is 32. When the alarm is in breach, if the scaling policy decrements the desired capacity by 1, then no scaling action is taken. @@ -170 +170 @@ If you use instance weights, keep in mind that the current capacity of your Auto -For step scaling, you can optionally specify the number of seconds that it takes for a newly launched instance to warm up. Until its specified warmup time has expired, an instance is not counted toward the aggregated EC2 instance metrics of the Auto Scaling group. +For step scaling, you can optionally specify the number of seconds that it takes for a newly launched instance to warm up. Until its specified warmup time has expired, an instance is not counted toward the aggregated EC2 instance metrics of the Amazon EC2 Auto Scaling group. @@ -176 +176 @@ If the group scales out again, the instances that are still warming up are count -For example, let's say that you create a policy with two steps. The first step adds 10 percent when the metric gets to 60, and the second step adds 30 percent when the metric gets to 70 percent. Your Auto Scaling group has a desired and current capacity of 10. The desired and current capacity do not change while the aggregated metric value is less than 60. Suppose that the metric gets to 60, so 1 instance is added (10 percent of 10 instances). Then, the metric gets to 62 while the new instance is still warming up. The scaling policy calculates the new desired capacity based on the current capacity, which is still 10. However, the desired capacity of the group has already increased to 11 instances, so the scaling policy does not increase the desired capacity further. If the metric gets to 70 while the new instance is still warming up, we should add 3 instances (30 percent of 10 instances). However, the desired capacity of the group is already 11, so we add only 2 instances, for a new desired capacity of 13 instances. +For example, let's say that you create a policy with two steps. The first step adds 10 percent when the metric gets to 60, and the second step adds 30 percent when the metric gets to 70 percent. Your Amazon EC2 Auto Scaling group has a desired and current capacity of 10. The desired and current capacity do not change while the aggregated metric value is less than 60. Suppose that the metric gets to 60, so 1 instance is added (10 percent of 10 instances). Then, the metric gets to 62 while the new instance is still warming up. The scaling policy calculates the new desired capacity based on the current capacity, which is still 10. However, the desired capacity of the group has already increased to 11 instances, so the scaling policy does not increase the desired capacity further. If the metric gets to 70 while the new instance is still warming up, we should add 3 instances (30 percent of 10 instances). However, the desired capacity of the group is already 11, so we add only 2 instances, for a new desired capacity of 13 instances. @@ -178 +178 @@ For example, let's say that you create a policy with two steps. The first step a -While the scale-out activity is in progress, all scale-in activities initiated by scaling policies are blocked until the instances finish warming up. When the instances finish warming up, if a scale-in event occurs, any instances currently in the process of terminating will be counted towards the current capacity of the group when calculating the new desired capacity. Therefore, we don't remove more instances from the Auto Scaling group than necessary. For example, while an instance is already terminating, if an alarm is in breach in the range of the same step adjustment that decremented the desired capacity by 1, then no scaling action is taken. +While the scale-out activity is in progress, all scale-in activities initiated by scaling policies are blocked until the instances finish warming up. When the instances finish warming up, if a scale-in event occurs, any instances currently in the process of terminating will be counted towards the current capacity of the group when calculating the new desired capacity. Therefore, we don't remove more instances from the Amazon EC2 Auto Scaling group than necessary. For example, while an instance is already terminating, if an alarm is in breach in the range of the same step adjustment that decremented the desired capacity by 1, then no scaling action is taken.