Was studying about Amazon web services and fundamentals when came across these 2 concepts:
Amazon CloudWatch
Amazon CloudWatch Events
Even while going through the official documents on AWS, I couldn't find a difference between the two even when Amazon mentions that they are different. Excerpt is:
CloudWatch provides you with data and actionable insights to monitor
your applications, respond to system-wide performance changes,
optimize resource utilization, and get a unified view of operational
health. CloudWatch collects monitoring and operational data in the
form of logs, metrics, and events, providing you with a unified view
of AWS resources, applications, and services that run on AWS and
on-premises servers. You can use CloudWatch to detect anomalous behavior in your environments, set alarms, visualize logs and metrics side by side, take automated actions, troubleshoot issues, and discover insights to keep your applications
running smoothly.
Documentation of AWS CloudWatch
Amazon CloudWatch Events delivers a near real-time stream of system
events that describe changes in Amazon Web Services (AWS) resources.
Using simple rules that you can quickly set up, you can match events
and route them to one or more target functions or streams. CloudWatch
Events becomes aware of operational changes as they occur. CloudWatch
Events responds to these operational changes and takes corrective
action as necessary, by sending messages to respond to the
environment, activating functions, making changes, and capturing
state information.
Documentation of AWS CloudWatch Events
CloudWatch
CloudWatch is a monitoring service for your AWS resources. You can log your log files. By default the resources created within AWS logs in CloudWatch(CW). You can monitor the performance of resources too for example you can monitor how is the CPU utilisation of your EC2 instances. You can set Alarms for your resources
threshold and get an SNS alert on that. For example you can create an Alarm for your DynamoDB if Write capacity is exceeding. You can set an alarm for your billing too. So basically CW is used as a Monitoring solution.
CloudWatch Events
CW Events is also the part of CloudWatch. CloudWatch Events is helpful when you want to schedule something. Say you to want run your lambda every other day, you can create a Rule for that or you want to trigger your lambda by Event Pattern. There are bunch of services supported by CloudWatch Events, you can use anyone of them as your target not just Lambda. Event Buses is used to send your events to multiple accounts also. For example if you have a CICD account and every month you bake new AMI there, to notify all accounts you can use Event Buses, after getting the event from Event Buses other accounts can trigger some important tasks.
Related
I have an on-premise app deployed in an Application Server (e.g. Tomcat) and it generates its own log file. If I decide to migrate this to an AWS EC2, including the Application Server, is it possible to port my application logs in Cloudwatch instead? or is Cloudwatch only capable of logging the runtime logs in my application server? is it a lot of work to do this or is this even possible?
Kind of confuse on Cloudwatch. Seems it can do multiple things but is it really right to make it do that? Its only supposed to log metrics right, so it can alert whatever or whoever needs to be alerted.
If you have already developed application that produces its own log files, you can use CloudWatch Logs Agent to ingest the logs into CloudWatch Logs:
After installation is complete, logs automatically flow from the instance to the log stream you create while installing the agent. The agent confirms that it has started and it stays running until you disable it.
The metrics, such as RAM usage, disk space, can also be monitored and pushed to CloudWatch through the agent.
In both cases, logs and metrics, you can setup CloudWatch Alarms to automatically detect anomalies and notify you, or perform other actions, when they are detected. For logs, this is done through metric filters:
You can search and filter the log data coming into CloudWatch Logs by creating one or more metric filters. Metric filters define the terms and patterns to look for in log data as it is sent to CloudWatch Logs. CloudWatch Logs uses these metric filters to turn log data into numerical CloudWatch metrics that you can graph or set an alarm on.
update
You can also have your application to inject logs directly to CloudWatch logs using AWS SDK. For example, in python, you can use put_log_events.
I am using various AWS services (Lambda, Glue, S3, Redshift, EC2) for ETL processing. I am trying to create a 'log ETL flow' to have monitoring and notifications sent out (email or otherwise) when a step fails in the process.
I have checked that each service I am using has metrics being logged in CloudWatch. I am now trying to figure out a smart way of processing this data in order to send out notifications when a step fails and/or have a central monitoring of the entire flow.
Are there any best practices or examples of this setup?
It seems to be the perfect case for the CloudWatch Alarms.
You can create a CloudWatch alarm that watches a single CloudWatch metric or the result of a math expression based on CloudWatch metrics. The alarm performs one or more actions based on the value of the metric or expression relative to a threshold over a number of time periods. The action can be an Amazon EC2 action, an Amazon EC2 Auto Scaling action, or a notification sent to an Amazon SNS topic.
You can create a chain CloudWatch Alarm -> SNS
You can either use SNS to notify users via SMS or Push Notifications.
Or you can do one step more SNS -> SES to deliver emails.
I need something like SQS that would call my api on schedule. Also I need to be able to create new "schedules"
AWS Cloudwatch events is what you are looking for:
Events—An event indicates a change in your AWS environment. AWS resources can generate events when their state changes. For example, Amazon EC2 generates an event when the state of an EC2 instance changes from pending to running, and Amazon EC2 Auto Scaling generates events when it launches or terminates instances. AWS CloudTrail publishes events when you make API calls. You can generate custom application-level events and publish them to CloudWatch Events. You can also set up scheduled events that are generated on a periodic basis. For a list of services that generate events, and sample events from each service, see CloudWatch Events Event Examples From Supported Services.
https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/WhatIsCloudWatchEvents.html
With CloudWatch you can monitor applications running on AWS. Is it also possible to monitor an external service?
For example, I have a REST API and I want to get notified once that API is not accessible anymore. Does AWS offer you a monitoring tool for that purpose?
Not Cloudwatch just by itself, but you can use a combination of Cloudwatch and Lambdas to do what you're asking. You can use cloudwatch events to run lambdas on a schedule, something like once every 5 mins.
CloudwatchEvents -> HealthCheck Lambda -> Cloudwatch Custom Metrics
Your lambda can then ping the API you're monitoring the health of, and either send its status to cloudwatch as a custom metric; or potentially if your lambda throws an error when the API fails, the lambda error metric which is already in cloudwatch becomes your API failure metric
Once the metric exists in cloudwatch, either as a custom metric or the lambda metric by proxy, you're able to do usual cloudwatch things like alarms and notifications.
Now there is a simple way to monitor external resources - CloudWatch Synthetics. Just create a canary to regularly monitor a website, API or even validate a multi-step UI flow.
Read more in the docs: CloudWatch > Using Synthetic Monitoring
Amazon CloudWatch supports custom metrics generated by your applications and services that you do not run on AWS. In this way, CloudWatch can be an integrated storage and aggregation point, allowing you to monitor all of the metrics that you collect, and track on a single platform.
There might be more than one way to reach your goal by using the AWS CLI, an API/SDK, or the CloudWatch collectd plugin etc. I'd recommend you take a look at these links for more details: link-1, link-2, link-3, link-4
Amazon Cloudwatch provides some very useful metrics for monitoring my EC2s, load balancers, elasticache and RDS databases, etc and allows me to set alarms for a whole range of criteria; but is there any way to configure it to monitor my S3s as well? Or are there any other monitoring tools (besides simply enabling logging) that will help me monitor the numbers of POST/GET requests and data volumes for my S3 resources? And to provide alarms for thresholds of activity or increased datastorage?
AWS S3 is a managed storage service. The only metrics available in AWS CloudWatch for S3 are NumberOfObjects and BucketSizeBytes. In order to understand your S3 usage better you need to do some extra work.
I have recently written an AWS Lambda function to do exactly what you ask for and it's available here:
https://github.com/maginetv/s3logs-cloudwatch
It works by parsing S3 Server side log files and aggregates/exports metrics to AWS Cloudwatch (CloudWatch allows you to publish custom metrics).
Example graphs that you will get in AWS CloudWatch after deploying this function on your AWS account are:
RestGetObject_RequestCount
RestPutObject_RequestCount
RestHeadObject_RequestCount
BatchDeleteObject_RequestCount
RestPostMultiObjectDelete_RequestCount
RestGetObject_HTTP_2XX_RequestCount
RestGetObject_HTTP_4XX_RequestCount
RestGetObject_HTTP_5XX_RequestCount
+ many others
Since metrics are exported to CloudWatch, you can easily set up alarms for them as well.
CloudFormation template is included in GitHub repo and you can deploy this function very quickly to gain visibility into your S3 bucket usage.
EDIT 2016-12-10:
In November 2016 AWS has added extra S3 request metrics in CloudWatch that can be enabled when needed. This includes metrics like AllRequests, GetRequests, PutRequests, DeleteRequests, HeadRequests etc. See Monitoring Metrics with Amazon CloudWatch documentation for more details about this feature.
I was also unable to find any way to do this with CloudWatch. This question from April 2012 was answered by Derek#AWS as not having S3 support in CloudWatch. https://forums.aws.amazon.com/message.jspa?messageID=338089
The only thing I could think of would be to import the S3 access logs to a log service (like Splunk). Then create a custom cloud watch metric where you post the data that you parse from the logs. But then you have to filter out the polling of the access logs and…
And while you were at it, you could just create the alarms in Splunk instead of in S3.
If your use case is to simply alert when you are using it too much, you could set up an account billing alert for your S3 usage.
I think this might depend on where you are looking to track the access from. I.e. if you are trying to measure/watch usage of S3 objects from outside http/https requests then Anthony's suggestion if enabling S3 logging and then importing into splunk (or redshift) for analysis might work. You can also watch billing status on requests every day.
If trying to guage usage from within your own applications, there are some AWS SDK cloudwatch metrics:
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/metrics/package-summary.html
and
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/metrics/S3ServiceMetric.html
S3 is a managed service, meaning that you don't need to take action based on system events in order to keep it up and running (as long as you can afford to pay for the service's usage). The spirit of CloudWatch is to help with monitoring services that require you to take action in order to keep them running.
For example, EC2 instances (which you manage yourself) typically need monitoring to alert when they're overloaded or when they're underused or else when they crash; at some point action needs to be taken in order to spin up new instances to scale out, spin down unused instances to scale back in, or reboot instances that have crashed. CloudWatch is meant to help you do the job of managing these resources more effectively.
To enable Request and Data transfer metrics in your bucket you can run the below command. Be aware that these are paid metrics.
aws s3api put-bucket-metrics-configuration \
--bucket YOUR-BUCKET-NAME \
--metrics-configuration Id=EntireBucket
--id EntireBucket
This tutorial describes how to do it in AWS Console with point and click interface.