Simple Log Service:Use GetHistograms to query the distribution of logs

Usage notes

In this example, the public Simple Log Service endpoint for the China (Hangzhou) region is used, which is https://cn-hangzhou.log.aliyuncs.com. If you want to access Simple Log Service by using other Alibaba Cloud services that reside in the same region as your project, you can use the internal Simple Log Service endpoint, which is https://cn-hangzhou-intranet.log.aliyuncs.com. For more information about the supported regions and endpoints of Simple Log Service, see Endpoints.

Raw log

body_bytes_sent:1750
host:www.example.com
http_referer:www.example.com
http_user_agent:Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; it-it) AppleWebKit/533.20.25 (KHTML, like Gecko) Version/5.0.4 Safari/533.20.27
http_x_forwarded_for:203.0.XX.XX
remote_addr:203.0.XX.XX
remote_user:p288
request_length:13741
request_method:GET
request_time:71
request_uri:/request/path-1/file-1
http_code:200
time_local:11/Aug/2021:06:52:27
upstream_response_time:0.66

Sample code

The following sample code provides an example on how to query the distribution of access requests from 47.100.XX.XX within an hour:

import com.aliyun.openservices.log.Client;
import com.aliyun.openservices.log.common.Histogram;
import com.aliyun.openservices.log.exception.LogException;
import com.aliyun.openservices.log.response.GetHistogramsResponse;

public class GetHistograms {
    public static void main(String[] args) throws LogException {
        // In this example, the AccessKey ID and AccessKey secret are obtained from environment variables. 
        String accessId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
        String accessKey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
        // The name of the project. 
        String projectName = "ali-test-project";
        // The Simple Log Service endpoint. In this example, the Simple Log Service endpoint for the China (Hangzhou) region is used. Replace the parameter value with the actual endpoint. 
        String host = "https://cn-hangzhou.log.aliyuncs.com";

        // Create a Simple Log Service client. 
        Client client = new Client(host, accessId, accessKey);

        try {
            // The name of the Logstore. 
            String logstoreName = "ali-test-logstore";

            // Query the distribution of access requests from 47.100.XX.XX within an hour. 
            String query = "remote_addr:47.100.XX.XX";
            System.out.println(String.format("ready to get histograms from %s",logstoreName));

            // The fromTime and toTime parameters specify the start time and end time of the time range within which you want to query logs. The values of the parameters are UNIX timestamps. Set the time range to 1 hour. 
            int fromTime = (int) (System.currentTimeMillis()/1000 - 3600);
            int toTime = fromTime + 3600;

            GetHistogramsResponse response = client.GetHistograms(projectName,logstoreName,fromTime,toTime,"",query);
            for (Histogram histogram : response.GetHistograms()) {
                // Only the subintervals within which logs are distributed are returned. 
                if (0 < histogram.GetCount()){
                    // The number of logs that are returned. 
                    System.out.println("log number is :" + histogram.GetCount());
                    // The start time of the subinterval. 
                    System.out.println("from time is :" + histogram.GetFrom());
                    // The end time of the subinterval. 
                    System.out.println("to time is :" + histogram.GetTo());
                    // Check whether the query result in the subinterval is complete. 
                    System.out.println("is completed :" + histogram.IsCompleted());
                }
            }
            System.out.println(String.format("get histograms from %s success",logstoreName));

        } catch (LogException e) {
            System.out.println("LogException e :" + e.toString());
            System.out.println("error code :" + e.GetErrorCode());
            System.out.println("error message :" + e.GetErrorMessage());
            throw e;
        }
    }
}

The following sample code shows the expected results. The number of access requests from 47.100.XX.XX within 1 hour is 10, and the query result is complete.

ready to get histograms from nginx-moni
log number is :10
from time is :1667875920
to time is :1667879520
is completed :true
get histograms from nginx-moni success

References

• If the response that is returned by Log Service contains error information after you call an API operation, the call fails. You can handle errors based on the error codes that are returned when API calls fail. For more information, see Error codes.
• Alibaba Cloud OpenAPI Explorer provides debugging capabilities, SDKs, examples, and related documents. You can use OpenAPI Explorer to debug Log Service API operations without the need to manually encapsulate or sign requests. For more information, visit OpenAPI Portal.
• Log Service provides the command-line interface (CLI) to meet the requirements for automated configurations in Log Service. For more information, see Log Service CLI.

• For more information about the GetHistograms operation, see GetHistograms.

• For more information about sample code, see Alibaba Cloud Log Service SDK for Java on GitHub.