Log Service allows you to aggregate data from multiple source Logstores to a single destination Logstore. To do this, you can configure a data transformation task for each source Logstore. This topic describes how to aggregate data from multiple source Logstores to a destination Logstore in a typical scenario.

Background information

For example, assume that a multinational information company stores the access logs of its website in different Logstores that belong to different Alibaba Cloud accounts. The company needs to aggregate the access logs from the Logstores in the UK (London) region for data query and analysis. To do this, the company can use the e_output function in Log Service to aggregate the transformation results to a destination Logstore.

Aggregate data from multiple source Logstores

  • Raw log entries
    • The raw log entries are stored in a Logstore named Logstore_1 of a project named Project_1. The project belongs to Account 1 and resides in the UK (London) region.
      Log entry 1
      request_id: 1
      http_host:  m1.abcd.com
      http_status:  200
      request_method:  GET
      request_uri:  /pic/icon.jpg
      
      Log entry 2
      request_id: 2
      http_host:  m2.abcd.com
      http_status:  301
      request_method:  POST
      request_uri:  /data/data.php
    • The raw log entries are stored in a Logstore named Logstore_2 of a project named Project_2. The project belongs to Account 2 and resides in the UK (London) region.
      Log entry 1
      request_id: 3
      host:  m3.abcd.com
      status:  404
      request_method:  GET
      request_uri:  /category/abc/product_id
      
      Log entry 2
      request_id: 4
      host:  m4.abcd.com
      status:  200
      request_method:  GET
      request_uri:  /data/index.html
  • Transformation requirements
    • Aggregate the log entries whose http_status is 200 in Logstore_1 of Account 1 and Logstore_2 of Account 2 to Logstore_3 of Account 3.
    • Set the log field names in Logstore_1 of Account 1 and Logstore_2 of Account 2. Set the field name host to http_host and the field name status to http_status.
  • DSL orchestration
    • Configure the following transformation rules for Logstore_1 of Account 1. On the Create Data Transformation Rule page, set Target Name to target_logstore, set Target Project to Project_3, set Target Logstore to Logstore_3, and specify the authorization method. For more information, see Create a data transformation rule.
      e_if(e_match("http_status", "200"), e_output("target_logstore"))
      Transformation rule
    • Configure the following transformation rules for Logstore_2 of Account 2. On the Create Data Transformation Rule page, set Target Name to target_logstore, set Target Project to Project_3, set Target Logstore to Logstore_3, and specify the authorization method.
      e_if(e_match("status", "200"), e_compose(e_rename("status", "http_status", "host", "http_host"), e_output("target_logstore")))
  • Result

    The following log entries are aggregated in the Logstore_3 of Project_3 that belongs to Account 3. The project resides in the UK (London) region.

    Log entry 1
    request_id: 1
    http_host:  m1.abcd.com
    http_status:  200
    request_method:  GET
    request_uri:  /pic/icon.jpg
    
    Log entry 2
    request_id: 4
    http_host:  m4.abcd.com
    http_status:  200
    request_method:  GET
    request_uri:  /data/index.html