AWS CloudWatch allows you to store and display metrics and logs as well as generate alarms to alert you when things go wrong. It obviously integrates very well with other AWS services such as EC2, and you can also use it for workloads located outside of AWS on-premises servers, for example.
It uses a custom query language to easily allow you to filter through the log data and extract the information you want. You can then analyze the results and display them in a graphical way.
Logs are organized in log groups and log streams. That is, a log group cannot contain another log group. A log stream is similar to a file, where the log data will be stored. The screenshot below shows what this console looks like. In the top-right corner, you can find a box where you can filter the logs based on a date and range of time.
This view is quite limited and useful only for a quick glance at simple logs. In AWS, your code can run in different ways. The first and most obvious way that your code is run is on an EC2 instance. In the case of Kubernetesyou can also configure the control plane to send logs to CloudWatch Logs. But you can still stream the logs to another service for custom processing if necessary.
Many AWS services either send their logs to CloudWatch Logs by default or allow you to do so through some configuration. Another example is VPC flow logs. VPC Virtual Private Cloud allows you to build a virtual networking environment for your apps and databases and replicates a kubernetes secrets encryption networking setup with subnets, firewalls, and routers.
Enabling flow logs can generate a lot of data depending on how much of it you enable and the volume of your VPC networking traffic. So you should turn off VPC flow logs as soon as the problem has been solved. It is entirely possible for you to use a custom or in-house solution to ingest log data into AWS CloudWatch. In order to filter the data, CloudWatch Logs Insight uses a custom query languagewhich is fairly intuitive especially for those familiar with SQL since AWS CloudWatch Logs Insight automatically detects fields in formatted logs and provides auto-completion features.
In any case, you have three fields that are always available to you:. For other types of logs e. Up to six commands can be stringed in this way. This selects the timestamp and message fields from log messages, sorts them with the most recent on top, and displays only the first 20 results.
On the top-right corner of the screen, you can also find very helpful reminders of what commands are available and their syntax. The following screenshot shows what such a graph looks like:.
AWS CloudWatch is a very capable and scalable solution to ingest, store, and process log data. And it integrates very well with other AWS services. For very large and complex projects, third-party solutions such as Epsagon might be more appropriate. Also, its ability to stream data to Lambda and Kinesis allows literally limitless possibilities in terms of custom processing. Instrumentation for Better Monitoring and Troubleshooting.
Why Epsagon Overview Customers. Microservices Serverless Security. Author: Nitzan Shapira. For example: VPC flow logs when enabled. Lambda output. How to Feed Log Data? In any case, you have three fields that are always available to you: message contains the log text.If you've got a moment, please tell us what we did right so we can do more of it.
Thanks for letting us know this page needs work. We're sorry we let you down. If you've got a moment, please tell us how we can make the documentation better. Find the IP addresses where flow records were skipped during the capture window. Find the number of records by domain and subdomain where the server failed to complete the DNS request. Use a glob expression to extract the ephemeral fields usermethodand latency from the log field message and return the average latency for each unique combination of method and user.
Amazon CloudWatch FAQs
Do not use an associate an asymmetric CMK with your log group. For more information, see Using Symmetric and Asymmetric Keys. This must be a symmetric CMK. Creates an export task, which allows you to efficiently export data from a log group to an Amazon S3 bucket. This is an asynchronous call. If all the required information is provided, this operation initiates an export task and responds with the ID of the task.
After the task has started, you can use DescribeExportTasks to get the status of the export task. To cancel an export task, use CancelExportTask. You can export logs from multiple log groups or multiple time ranges to the same S3 bucket. To separate out log data for each export task, you can specify a prefix to be used as the Amazon S3 key prefix for all exported objects.
Exporting to S3 buckets that are encrypted with AES is supported. The start time of the range for the request, expressed as the number of milliseconds after Jan 1, UTC. Events with a timestamp earlier than this time are not exported. The end time of the range for the request, expressed as the number of milliseconds after Jan 1, UTC.
Events with a timestamp later than this time are not exported. Do not associate an asymmetric CMK with your log group. There is no limit on the number of log streams that you can create for a log group.
Deletes the specified destination, and eventually disables all the subscription filters that publish to it. This operation does not delete the physical resource encapsulated by the destination. Deletes the specified log group and permanently deletes all the archived log events associated with the log group. Deletes the specified log stream and permanently deletes all the archived log events associated with the log stream.
Deletes a resource policy from this account. This revokes the access of the identities in that policy to put log events to this account. The creation time of the destination, expressed as the number of milliseconds after Jan 1, UTC.
Lists the specified export tasks. You can list all your export tasks or filter the results based on task ID or task status. The start time, expressed as the number of milliseconds after Jan 1, UTC. Events with a timestamp before this time are not exported. The end time, expressed as the number of milliseconds after Jan 1, UTC.
The creation time of the export task, expressed as the number of milliseconds after Jan 1, UTC.How to query logs in AWS CloudWatch
The completion time of the export task, expressed as the number of milliseconds after Jan 1, UTC. Lists the specified log groups.
You can list all your log groups or filter the results by prefix. The creation time of the log group, expressed as the number of milliseconds after Jan 1, UTC. The number of days to retain the log events in the specified log group.
Possible values are: 1, 3, 5, 7, 14, 30, 60, 90,, and Lists the log streams for the specified log group.You can use Amazon CloudWatch to collect and track metrics, collect and monitor log files, and set alarms. You can use Amazon CloudWatch to gain system-wide visibility into resource utilization, application performance, and operational health. You can use these insights to react and keep your application running smoothly. To get started with monitoring, you can use Automatic Dashboards with built-in AWS best practices, explore account and resource-based view of metrics and alarms, and easily drill-down to understand the root cause of performance issues.
Amazon CloudWatch receives and provides metrics for all Amazon EC2 instances and should work with any operating system currently supported by the Amazon EC2 service. For example, you could create an IAM policy that gives only certain users in your organization permission to use GetMetricStatistics. They could then use the action to retrieve data about your cloud resources.
For example, you can't give a user access to CloudWatch data for only a specific set of instances or a specific LoadBalancer. Amazon CloudWatch Logs lets you monitor and troubleshoot your systems and applications using your existing system, application and custom log files.
With CloudWatch Logs, you can monitor your logs, in near real time, for specific phrases, values or patterns. For example, you could set an alarm on the number of errors that occur in your system logs or view graphs of latency of web requests from your application logs. You can then view the original log data to see the source of the problem. CloudWatch Logs is capable of monitoring and storing your logs to help you better understand and operate your systems and applications.
You can use CloudWatch Logs in a number of ways. Real time application and system monitoring: You can use CloudWatch Logs to monitor applications and systems using log data. For example, CloudWatch Logs can track the number of errors that occur in your application logs and send you a notification whenever the rate of errors exceeds a threshold you specify.
CloudWatch Logs uses your log data for monitoring; so, no code changes are required. Long term log retention: You can use CloudWatch Logs to store your log data indefinitely in highly durable and cost effective storage without worrying about hard drives running out of space. The CloudWatch Logs Agent makes it easy to quickly move both rotated and non rotated log files off of a host and into the log service.
You can then access the raw log event data when you need it. This agent will support the ability to monitor individual log files on the host. It helps developers, operators, and systems engineers understand, improve, and debug their applications, by allowing them to search and visualize their logs. Logs Insights is fully integrated with CloudWatch, enabling you to manage, explore, and analyze your logs.
You can also leverage CloudWatch Metrics, Alarms and Dashboards with Logs to get full operational visibility into your applications.
This empowers you to understand your applications, make improvements, and find and fix problems quickly, so that you can continue to innovate rapidly. You can write queries with aggregations, filters, and regular expressions to derive actionable insights from your logs. You can also visualize timeseries data, drill down into individual log events, and export your query results to CloudWatch Dashboards.
You can immediately start using Logs Insights to run queries on all your logs being sent to CloudWatch Logs. There is no setup required and no infrastructure to manage. CloudWatch Container Insights is a feature for monitoring, troubleshooting, and alarming on your containerized applications and microservices. Container Insights simplifies the isolation and analysis of performance issues impacting your container environment. You can get started collecting detailed performance metrics, logs, and metadata from your containers and clusters in just a few clicks by following these steps in the CloudWatch Container Insights documentation.
Amazon CloudWatch Anomaly Detection applies machine-learning algorithms to continuously analyze single time series of systems and applications, determine a normal baseline, and surface anomalies with minimal user intervention.
It allows you to create alarms that auto-adjust thresholds based on natural metric patterns, such as time of day, day of week seasonality or changing trends. You can also visualize metrics with anomaly detection bands on dashboards, monitoring, isolating, and troubleshooting unexpected changes in your metrics.
It is easy to get started with Anomaly Detection.First, just based on the service name, I expected that search inside the logs will be more user friendly and quicker. So, the old problem with quick search in logs still exist.
Best approach to make your life more bearable is to have good standardized logs with keywords and good json structure. AWS CloudWatch is about log analytics. Yes, query results are really quick and you only pay for the queries you run. In addition, you can publish log-based metrics, create alarms, and correlate logs and metrics together in CloudWatch Dashboards for complete operational visibility. No heavy calculations or processing inside, only re-mapping of data.
Many times, a client is claiming that the Lambda function is slow with bad response time or error message in response. But, how far did I go? Here, you can see the new operation that is available — CloudWatch Logs Insights:. I want to see a list of the number of exceptions per hour in the last 24h. Next to Log group name, I chose 1d and run the following query:.
CloudWatch Logs Insights Query Syntax
This query returns me a number of messages that contain Error in text that is how my log is structured grouped hourly using bin. I can preview as a line or stacked area graph. Bin helps you quickly visualize trends in log events over time. From the results I can find the error details and log stream — if I want to see full request info:.
This information is available after each processed request in CloudWatch under Report record type:. Except the time interval when performance testing was conducted, I usually have average requests hourly, with average duration of 5ms. I have MB overprovisioned memory.
This affects my billed time and needs to be changed, especially because I do not have heavy calculations and processing inside. Performance and cost optimization are still an open issue in the serverless world. There is still no objective way of measuring and optimizing execution, due to many factors that are outside our control. I hope this CloudWatch Logs Insights can help us take more data-driven decisions, and save some time while optimizing our Lambda Functions.
I have a lot of AWS Lambda logs which I need to query to find the relevant log stream name, I am logging a particular string in the logs, Which I need to do a like or exact query on. Have you tried adding an additional filter on the message field to your first query to further narrow your results?
Alternatively if all of your logs follow the same format you could use the parse keyword to split out your UUID field and search on it with something like.
Also try widening your relative time range at the top right of the query, just in case the request you're looking for has dropped outside of the 1hr range since attempting the first query. Learn more. Ask Question. Asked 6 months ago. Active 6 months ago. Viewed 1k times. Ani Ani 2, 2 2 gold badges 26 26 silver badges 70 70 bronze badges. Active Oldest Votes. Patrick Patrick 1 1 silver badge 7 7 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook.
Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Programming tutorials can be a real drag. Featured on Meta. Community and Moderator guidelines for escalating issues via new response…. Feedback on Q2 Community Roadmap.
CloudWatch Logs Insights supports a query language you can use to perform queries on your log groups. Each query can include one or more query commands separated by Unix-style pipe characters.
Six query commands are supported, along with many supporting functions and operations, including regular expressions, arithmetic operations, comparison operations, numeric functions, datetime functions, string functions, and generic functions. Comments are also supported. Lines in a query that start with the character are ignored. The following table lists the six supported query commands along with basic examples.
For more powerful sample queries, see Sample Queries. Specifies which fields to display in the query results.
If you specify this command more than once in your query, only the fields you specify in the last occurrence are used. This example uses the field message and creates the ephemeral fields loggingType and loggingMessage for use in the query. It filters the events to only those with ERROR as the value of loggingTypebut then displays only the loggingMessage field in the results. Retrieves the specified fields from log events. You can use functions and operations within a fields command.
This example retrieves the fields foo-baractionand the absolute value of the difference between f3 and f4 for all log events in the log group. Any log field named in a query that has characters other than the sign, the period.
Filters the results of a query based on one or more conditions. You can use in to test for set membership. Put an array with the elements to check for immediately after in. You can use not with in. Instead, the results show the timestamp and all log data in the message field for all log events where duration is more than Calculates aggregate statistics based on the values of log fields.
Several statistical operators are supported, including sumavgcount,minand max. When you use statsyou can also use by to specify one or more criteria to use to group data when calculating the statistics.
Sorts the retrieved log events. Both ascending asc and descending desc order are supported. You can use this to limit the results to a small number to see a small set of relevant results. You can also use limit with a number between and 10, to increase the number of query result rows displayed in the console to an amount greater than the default of rows. In this case the sort order is by timestamp starting with the most recent, so the most recent 25 events are returned.