Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Sample queries

This section contains a list of general and useful query commands that you can run in the CloudWatch console. For information about how to run a query command, see Tutorial: Run and modify a sample query in the Amazon CloudWatch Logs User Guide.

For more information about query syntax, see CloudWatch Logs Insights language query syntax.

General queries

Find the 25 most recently added log events.

fields @timestamp, @message | sort @timestamp desc | limit 25

Get a list of the number of exceptions per hour.

filter @message like /Exception/ 
    | stats count(*) as exceptionCount by bin(1h)
    | sort exceptionCount desc
    

Get a list of log events that aren't exceptions.

fields @message | filter @message not like /Exception/

Get the most recent log event for each unique value of the server field.

fields @timestamp, server, severity, message 
| sort @timestamp asc 
| dedup server

Get the most recent log event for each unique value of the server field for each severity type.

fields @timestamp, server, severity, message 
| sort @timestamp desc 
| dedup server, severity

Queries for Lambda logs

Determine the amount of overprovisioned memory.

filter @type = "REPORT"
    | stats max(@memorySize / 1000 / 1000) as provisonedMemoryMB,
        min(@maxMemoryUsed / 1000 / 1000) as smallestMemoryRequestMB,
        avg(@maxMemoryUsed / 1000 / 1000) as avgMemoryUsedMB,
        max(@maxMemoryUsed / 1000 / 1000) as maxMemoryUsedMB,
        provisonedMemoryMB - maxMemoryUsedMB as overProvisionedMB
    

Create a latency report.

filter @type = "REPORT" |
    stats avg(@duration), max(@duration), min(@duration) by bin(5m)

Search for slow function invocations, and eliminate duplicate requests that can arise from retries or client-side code. In this query, @duration is in milliseconds.

fields @timestamp, @requestId, @message, @logStream 
| filter @type = "REPORT" and @duration > 1000
| sort @timestamp desc
| dedup @requestId 
| limit 20

Queries for Amazon VPC flow logs

Find the top 15 packet transfers across hosts:

stats sum(packets) as packetsTransferred by srcAddr, dstAddr
    | sort packetsTransferred  desc
    | limit 15

Find the top 15 byte transfers for hosts on a given subnet.

filter isIpv4InSubnet(srcAddr, "192.0.2.0/24")
    | stats sum(bytes) as bytesTransferred by dstAddr
    | sort bytesTransferred desc
    | limit 15
     
    

Find the IP addresses that use UDP as a data transfer protocol.

filter protocol=17 | stats count(*) by srcAddr

Find the IP addresses where flow records were skipped during the capture window.

filter logStatus="SKIPDATA"
    | stats count(*) by bin(1h) as t
    | sort t
    

Find a single record for each connection, to help troubleshoot network connectivity issues.

fields @timestamp, srcAddr, dstAddr, srcPort, dstPort, protocol, bytes 
| filter logStream = 'vpc-flow-logs' and interfaceId = 'eni-0123456789abcdef0' 
| sort @timestamp desc 
| dedup srcAddr, dstAddr, srcPort, dstPort, protocol 
| limit 20

Queries for Route 53 logs

Find the distribution of records per hour by query type.

stats count(*) by queryType, bin(1h)

Find the 10 DNS resolvers with the highest number of requests.

stats count(*) as numRequests by resolverIp
    | sort numRequests desc
    | limit 10

Find the number of records by domain and subdomain where the server failed to complete the DNS request.

filter responseCode="SERVFAIL" | stats count(*) by queryName

Queries for CloudTrail logs

Find the number of log entries for each service, event type, and Amazon Region.

stats count(*) by eventSource, eventName, awsRegion

Find the Amazon EC2 hosts that were started or stopped in a given Amazon Region.

filter (eventName="StartInstances" or eventName="StopInstances") and awsRegion="us-east-2"
    

Find the Amazon Regions, user names, and ARNs of newly created IAM users.

filter eventName="CreateUser"
    | fields awsRegion, requestParameters.userName, responseElements.user.arn
    

Find the number of records where an exception occurred while invoking the API UpdateTrail.

filter eventName="UpdateTrail" and ispresent(errorCode)
    | stats count(*) by errorCode, errorMessage
    

Find log entries where TLS 1.0 or 1.1 was used

filter tlsDetails.tlsVersion in [ "TLSv1", "TLSv1.1" ]
| stats count(*) as numOutdatedTlsCalls by userIdentity.accountId, recipientAccountId, eventSource, eventName, awsRegion, tlsDetails.tlsVersion, tlsDetails.cipherSuite, userAgent
| sort eventSource, eventName, awsRegion, tlsDetails.tlsVersion
            

Find the number of calls per service that used TLS versions 1.0 or 1.1

filter tlsDetails.tlsVersion in [ "TLSv1", "TLSv1.1" ]
| stats count(*) as numOutdatedTlsCalls by eventSource
| sort numOutdatedTlsCalls desc
            

Queries for Amazon API Gateway

Find the last 10 4XX errors

fields @timestamp, status, ip, path, httpMethod
| filter status>=400 and status<=499
| sort @timestamp desc
| limit 10

Identify the 10 longest-running Amazon API Gateway requests in your Amazon API Gateway access log group

fields @timestamp, status, ip, path, httpMethod, responseLatency
| sort responseLatency desc
| limit 10

Return the list of the most popular API paths in your Amazon API Gateway access log group

stats count(*) as requestCount by path
| sort requestCount desc
| limit 10

Create an integration latency report for your Amazon API Gateway access log group

filter status=200
| stats avg(integrationLatency), max(integrationLatency), 
min(integrationLatency) by bin(1m)

Queries for NAT gateway

If you notice higher than normal costs in your Amazon bill, you can use CloudWatch Logs Insights to find the top contributors. For more information about the following query commands, see How can I find the top contributors to traffic through the NAT gateway in my VPC? at the Amazon premium support page.

Find the instances that are sending the most traffic through your NAT gateway.

filter (dstAddr like 'x.x.x.x' and srcAddr like 'y.y.') 
| stats sum(bytes) as bytesTransferred by srcAddr, dstAddr
| sort bytesTransferred desc
| limit 10

Determine the traffic that's going to and from the instances in your NAT gateways.

filter (dstAddr like 'x.x.x.x' and srcAddr like 'y.y.') or (srcAddr like 'xxx.xx.xx.xx' and dstAddr like 'y.y.')
| stats sum(bytes) as bytesTransferred by srcAddr, dstAddr
| sort bytesTransferred desc
| limit 10         

Determine the internet destinations that the instances in your VPC communicate with most often for uploads and downloads.

For uploads

filter (srcAddr like 'x.x.x.x' and dstAddr not like 'y.y.') 
| stats sum(bytes) as bytesTransferred by srcAddr, dstAddr
| sort bytesTransferred desc
| limit 10

For downloads

filter (dstAddr like 'x.x.x.x' and srcAddr not like 'y.y.') 
| stats sum(bytes) as bytesTransferred by srcAddr, dstAddr
| sort bytesTransferred desc
| limit 10

Queries for Apache server logs

You can use CloudWatch Logs Insights to query Apache server logs. For more information about the following queries, see Simplifying Apache server logs with CloudWatch Logs Insights at the Amazon Cloud Operations & Migrations Blog.

Find the most relevant fields, so you can review your access logs and check for traffic in the /admin path of your application.

fields @timestamp, remoteIP, request, status, filename| sort @timestamp desc
| filter filename="/var/www/html/admin"
| limit 20    

Find the number unique GET requests that accessed your main page with status code "200" (success).

fields @timestamp, remoteIP, method, status
| filter status="200" and referrer= http://34.250.27.141/ and method= "GET"
| stats count_distinct(remoteIP) as UniqueVisits
| limit 10              

Find the number of times your Apache service restarted.

fields @timestamp, function, process, message
| filter message like "resuming normal operations"
| sort @timestamp desc
| limit 20                    

Queries for Amazon EventBridge

Get the number of EventBridge events grouped by event detail type

fields @timestamp, @message
| stats count(*) as numberOfEvents by `detail-type`
| sort numberOfEvents desc

Examples of the parse command

Use a glob expression to extract the fields @user, @method, and @latency from the log field @message and return the average latency for each unique combination of @method and @user.

parse @message "user=*, method:*, latency := *" as @user,
    @method, @latency | stats avg(@latency) by @method,
    @user

Use a regular expression to extract the fields @user2, @method2, and @latency2 from the log field @message and return the average latency for each unique combination of @method2 and @user2.

parse @message /user=(?<user2>.*?), method:(?<method2>.*?),
    latency := (?<latency2>.*?)/ | stats avg(latency2) by @method2, 
    @user2

Extracts the fields loggingTime, loggingType and loggingMessage, filters down to log events that contain ERROR or INFO strings, and then displays only the loggingMessage and loggingType fields for events that contain an ERROR string.

FIELDS @message
    | PARSE @message "* [*] *" as loggingTime, loggingType, loggingMessage
    | FILTER loggingType IN ["ERROR", "INFO"]
    | DISPLAY loggingMessage, loggingType = "ERROR" as isError