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This section details the tasks you can perform using CloudWatch.This section expands on the basic concepts presented in the preceding section (see CloudWatch Overview and includes procedures for using CloudWatch. This section also shows you how to view metrics that Eucalyptus services provide to CloudWatch and how to publish custom metrics with CloudWatch.
This section describes how to enable and disable monitoring for your cloud resources.
This section describes steps for enabling monitoring on your cloud resources.To enable monitoring on your resources, following the steps for your resource.
To enable monitoring for a running instance, enter the following command:
euca-monitor-instances [instance_id]
To enable monitoring when you launch an instance, enter the following command:
euca-run-instances [image_id] -k gsg-keypair --monitor
To enable monitoring for an existing Auto Scaling group: Create a launch configuration with --monitoring-enabled option. Make a euscale-update-auto-scaling-group request to update your Auto Scaling group with the launch configuration you created in the previous step. Auto Scaling will enable monitoring for new instances that it creates. Choose one of the following actions to deal with all existing instances in the Auto Scaling group:
| To . . . | Do this . . . |
|---|---|
| Preserve existing instances | Make a euca-monitor-instances request for all existing instances to enable monitoring. |
| Terminate existing instances | Make a euscale-terminate-instance-in-auto-scaling-group request for all existing instances. Auto Scaling will use the updated launch configuration to create replacement instances with monitoring enabled. |
To enable monitoring when you create a new Auto Scaling group: Create a launch configuration with --monitoring-enabled option.
Elastic Load Balancing (ELB) sends metrics and dimensions for all load balancers to CloudWatch. By default, you do not need to specifically enable monitoring.
This section describes steps for disabling monitoring on your cloud resources.To disable monitoring on your resources, following the steps for your resource.
To disable monitoring for a running instance, enter the following command:
euca-unmonitor-instances [instance_id]
To enable monitoring for an existing Auto Scaling group: Create a launch configuration with --monitoring-disabled option. Make a euscale-update-auto-scaling-group request to update your Auto Scaling group with the launch configuration you created in the previous step. Auto Scaling will disable monitoring for new instances that it creates. Choose one of the following actions to deal with all existing instances in the Auto Scaling group:
| To . . . | Do this . . . |
|---|---|
| Preserve existing instances | Make a euca-unmonitor-instances request for all existing instances to disable monitoring. |
| Terminate existing instances | Make a euscale-terminate-instance-in-auto-scaling-group request for all existing instances. Auto Scaling will use the updated launch configuration to create replacement instances with monitoring disabled. |
To enable monitoring when you create a new Auto Scaling group: Create a launch configuration with --monitoring-disabled option.
There is no way to disable monitoring for a load balancer.
This section describes how to view Eucalyptus metrics as well as how to publish your own metrics.
You can list available metrics via Euca2ools.To list available metrics:
Enter the following command.
euwatch-list-metrics
Eucalyptus returns a listing of all metrics, as shown in the following partial example output:
Metric Name Namespace Dimensions
CPUUtilization AWS/EC2 {InstanceId=i-5431413d}
CPUUtilization AWS/EC2 {InstanceType=m1.medium}
DiskReadBytes AWS/EC2 {InstanceId=i-1d3d4d74}
DiskReadBytes AWS/EC2 {InstanceType=m1.medium}
DiskReadOps AWS/EC2 {InstanceId=i-d3c8baba}
DiskReadOps AWS/EC2 {InstanceType=m1.medium}
DiskWriteBytes AWS/EC2 {InstanceId=i-6732420e}
DiskWriteBytes AWS/EC2 {InstanceType=m1.medium}
DiskWriteOps AWS/EC2 {InstanceId=i-e03d4d89}
DiskWriteOps AWS/EC2 {InstanceType=m1.medium}
NetworkIn AWS/EC2 {InstanceId=i-e0304089}
NetworkIn AWS/EC2 {InstanceType=m1.medium}
NetworkOut AWS/EC2 {InstanceId=i-69334300}
NetworkOut AWS/EC2 {InstanceType=m1.medium}
StatusCheckFailed AWS/EC2 {InstanceId=i-6f8418e6}
StatusCheckFailed AWS/EC2 {InstanceType=m1.medium}
StatusCheckFailed_Instance AWS/EC2 {InstanceId=i-6f8418e6}
StatusCheckFailed_Instance AWS/EC2 {InstanceType=m1.medium}
StatusCheckFailed_System AWS/EC2 {InstanceId=i-6f8418e6}
StatusCheckFailed_System AWS/EC2 {InstanceType=m1.medium}
You can get statistics for metrics via Euca2ools.To get statistics for a metric:
Enter the following command.
euwatch-get-stats -n NAMESPACE -s STAT1,STAT2,...
[--dimensions KEY1=VALUE1,KEY2=VALUE2,...]
[--start-time YYYY-MM-DDThh:mm:ssZ]
[--end-time YYYY-MM-DDThh:mm:ssZ] [--period SECONDS]
[--unit UNIT] [--show-empty-fields] [-U URL]
[--region USER@REGION] [-I KEY_ID] [-S KEY]
[--security-token TOKEN] [--debug] [--debugger]
[--version] [-h]
METRIC
The following example returns the average CPU utilization for the i-c08804a9 instance at one hour resolution.
euwatch-get-stats --namespace "AWS/EC2" --statistics "Average" \
--dimensions "InstanceId=i-c08804a9" --start-time 2016-12-14T23:00:00.000Z \
--end-time 2016-12-15T23:00:00.000Z --period 3600 CPUUtilization
The following example returns CPU utilization for all of your cloud’s instances.
euwatch-get-stats --namespace "AWS/EC2" --statistics "Average,Minimum,Maximum" \
--start-time 2016-02-14T23:00:00.000Z --end-time 2016-03-14T23:00:00.000Z \
--period 3600 CPUUtilization
CloudWatch allows you to publish your own metrics, such as application performance, system health, or customer usage.
To publish a single data point for a new or existing metric, call euwatch-put-data with one value and time stamp. For example, the following actions each publish one data point:
euwatch-put-data --metric-name PageViewCount --namespace "TestService" --value 2 --timestamp 2011-03-14T12:00:00.000Z
euwatch-put-data --metric-name PageViewCount --namespace "TestService" --value 4 --timestamp 2011-03-14T12:00:01.000Z
euwatch-put-data --metric-name PageViewCount --namespace "TestService" --value 5 --timestamp 2011-03-14T12:00:02.000Z
You can publish data points with time stamps as granular as one-thousandth of a second. However, CloudWatch aggregates the data to a minimum granularity of 60 seconds. For example, the PageViewCount metric from the previous examples contains three data points with time stamps just seconds apart. CloudWatch aggregates the three data points because they all have time stamps within a 60-second period.
CloudWatch uses 60-second boundaries when aggregating data points. For example, CloudWatch aggregates the data points from the previous example because all three data points fall within the 60-second period that begins at 2011-03-14T12:00:00.000Z and ends at 2011-03-14T12:00:59.999Z.
You can also aggregate your data before you publish to CloudWatch. When you have multiple data points per minute, aggregating data minimizes the number of calls to euwatch-put-data . For example, instead of calling euwatch-put-data multiple times for three data points that are within three seconds of each other, you can aggregate the data into a statistic set that you publish with one call:
euwatch-put-data --metric-name PageViewCount --namespace "TestService" -s "Sum=11,Minimum=2,Maximum=5,SampleCount=3" --timestamp 2011-03-14T12:00:00.000
When your data is more sporadic and you have periods that have no associated data, you can choose to publish the value zero (0) for that period or no value at all. You might want to publish zero instead of no value if you use periodic calls to PutMetricData to monitor the health of your application. For example, you can set an Amazon CloudWatch alarm to notify you if your application fails to publish metrics every five minutes. You want such an application to publish zeros for periods with no associated data.
You might also publish zeros if you want to track the total number of data points or if you want statistics such as minimum and average to include data points with the value 0.
You can modify metrics timing and reporting defaults.When using the default CloudWatch properties, metrics reporting can take around 15 minutes:
The sensor data point timing values can be shortened by changing variables in the CLC.
Modify the default polling interval CLC variable to a number less than 5.
cloud.monitor.default_poll_interval_mins
This is how often the CLC sends a request to the CC for sensor data. Default value is 5 minutes. Modify the history size CLC variable to a number less than 5.
cloud.monitor.history_size
This is how many data value samples are sent in each sensor data request. The default value is 5. The frequency requests is either 1 minute (if the cloud.monitor.default_poll_interval_mins is 1 minute) or half the value of cloud.monitor.default_poll_interval_mins if that value is greater). So by default, with a cloud.monitor.default_poll_interval_mins of 5 minutes and cloud.monitor.history_size size of 5, every 5 minutes the CLC asks for the last 5 data points from the CC, which should be timed for every 2.5 minutes (e.g., 2.5 minutes ago, 5 minutes ago, 7.5 minutes ago, and 10 minutes ago).
This section describes how to create, test, and delete and alarm.
You can create a CloudWatch alarm using a resource’s metric, and then add an action using the action’s dedicated Amazon Resource Name (ARN). You can add the action to any alarm state.
Enter the following command:
euwatch-put-metric-alarm [alarm_name] --unit Percent --namespace "AWS/EC2"
-- dimensions "InstanceId=[instance_id]" --statistic [statistic] --metric-name
[metric] --comparison-operator [operator] --threshold [value] --period
[seconds] --evaluation-periods [value] -- alarm-actions [action]
For example, the following triggers an Auto Scaling policy if the average CPUUtilization is less than 10 percent over a 24 hour period.
euwatch-put-metric-alarm test-Alarm --unit Percent --namespace "AWS/EC2"
-- dimensions "InstanceId=i-abc123" --statistic Average --metric-name CPUUtilization
--comparison-operator LessThanThreshold --threshold 10 --period 86400
--evaluation-periods 4 -- alarm-actions arn:aws:autoscaling::429942273585:scalingPolicy:
12ad560b-58b2-4051-a6d3-80e53b674de4:autoScalingGroupName/testgroup01:
policyName/testgroup01-pol01
You can test the CloudWatch alarms by temporarily changing the state of your alarm to “ALARM” using the command: euwatch-set-alarm-state .
euwatch-set-alarm-state --alarm-name TestAlarm --state ALARM
To delete an alarm, perform the following step.
Enter the following command:
euwatch-delete-alarms [alarm_name]
For example, to delete an alarm named TestAlarm enter:
euwatch-delete-alarms TestAlarm