Web Application Firewall:Query logs

Query and analyze logs

1. Log on to the WAF console. In the top navigation bar, select the resource group and the region to which your WAF instance belongs. The region can be Chinese Mainland or Outside Chinese Mainland.
2. In the left-side navigation pane, choose Security Operations > Log Service.
3. Select a domain name from the domain name drop-down list and turn on Status to enable log collection for the domain name.
   The domain name drop-down list, which is marked as 1 in the preceding figure, contains only the domain names that are protected by WAF. If the domain name for which you want to enable log collection is not contained in the drop-down list, add the domain name to WAF. For more information, see Tutorial.
4. On the Log Query tab, execute a query statement to query and analyze the logs of the protected object that you selected.
   1. Enter a query statement in the search box that is marked as 1 in the preceding figure.
      The query statement that you enter must use the syntax that is specific to Log Service. For more information about the syntax, see Search syntax. The log fields that are included in WAF logs are used as query fields in the query statements. For more information about the log fields that are supported by WAF, see Log fields supported by WAF.

      If you are not familiar with the query syntax, we recommend that you use the Advanced Search feature. To use the Advanced Search feature, you need only to expand Advanced Search above the search box, specify search conditions, and then click Search. A query statement is automatically generated in the search box based on the search conditions. The following table describes the search conditions that are supported by the Advanced Search feature.

      Search condition	Description
      IP	The IP address of the client that sends the request.
      Request ID	The unique ID that is generated by WAF for the client request. This ID is provided when WAF returns an error page or a response page that prompts the client to complete slider CAPTCHA verification to the client. You can use this ID to analyze and troubleshoot the error.
      Rule ID	The ID of the WAF protection rule that is matched by the request. You can obtain the ID on the Security Report page or by choosing System Management > Protection Rule Group.
      Server Response Code	The HTTP status code that the origin server sends in response to the request from WAF.
      Status Code Returned by WAF	The HTTP status code that WAF sends in response to the request from the client.
      Protection Features	The type of the WAF protection rule that is matched by the request. For more information about WAF protection rules and their configuration methods, see Overview.

   2. If you want to compute and analyze the query results, you must enter an analytic statement following the search statement in the search box. If you only want to query logs that meet the search conditions, skip this step.
      Analytic statements and search statements are separated by vertical bars (|). The analytic statements use the standard SQL-92 syntax. For more information about the analytic statements, see Log analysis overview.
   3. Specify the query time range by using the time selector that is marked as 2 in the preceding figure.
   4. Click Search & Analyze that is marked as 3 in the preceding figure.
      In the lower section of the page, you can view the query and analysis results in a log histogram and on the Raw Logs and Graph tabs. You can perform various operations based on the query and analysis results. For example, you can conduct quick analysis, generate charts, and configure alerts. For more information, see Manage query and analysis results and Create alert rules.
   For more log query and analysis examples, see the "Query and analysis examples" section in this topic.

Manage query and analysis results

Create alert rules

You can create alert rules based on the query and analysis results. After you create an alert rule, Log Service checks related query and analysis results on a regular basis. If a query and analysis result meets the trigger condition that you specified in the alert rule, Log Service sends an alert notification. This way, the service status is monitored in real time.

On the query and analysis page, you can choose Save as Alert > New Alert to configure alerts based on the query and analysis results. For more information, see Configure an alert rule.

Query and analysis examples

• Query the number of requests blocked by different WAF protection features every quarter hour. The results include the attack time (time), the numbers of requests blocked by Protection Rules Engine (wafmodule), requests blocked by the IP address blacklist and custom protection policies (aclmodule), and requests blocked by HTTP flood protection and custom protection policies (httpfloodmodule).

  * |
  SELECT
    time_series(__time__, '15m', '%H:%i', '0') as time,
    COUNT_if(final_plugin = 'waf') as "wafmodule",
    COUNT_if(final_plugin = 'acl') as "aclmodule",
    COUNT_if(final_plugin = 'cc') as "httpfloodmodule"
  GROUP by
    time
  ORDER by
    time

• Query the breakdown of protection features (final_plugin) that perform protection actions. The results include the numbers of times that the protection features are triggered (times), requested domain names (host), and protection features (final_plugin).

  * |
  SELECT
    count(*) as times,
    host,
    final_plugin
  GROUP by
    host,
    final_plugin
  ORDER by
    times desc

• Query the queries per second (QPS) every quarter hour. The results include the query time (time) and QPS (QPS).

  * |
  SELECT
    time_series(__time__, '15m', '%H:%i', '0') as time,
    count(*) / 900 as QPS
  GROUP by
    time
  ORDER by
    time

• Query the domain names that suffer the most HTTP flood attacks. The results include the number of times that HTTP flood attacks are blocked (times) and the requested domain names (host).

  *
  and acl_action :block |
  SELECT
    count(*) as times,
    host
  GROUP by
    host
  ORDER by
    times desc

• Query the log details about requests every second. The results include the request time (time), requested domain name (host), request path (request_path), request method (request_method), HTTP status code (status) that WAF responds, HTTP status code (upstream_status) that the origin server responds, and query string (querystring).

  * |
  SELECT
    date_format(date_trunc('second', __time__), '%H:%i:%s') as time,
    host,
    request_path,
    request_method,
    status,
    upstream_status,
    querystring
  LIMIT
    10

• Query the latest 10 attacks on the your_domain_name website. The results include the attack time (time), the originating IP address of the client, (real_client_ip), and client type (http_user_agent).

  matched_host: your_domain_name
  and final_action: block |
  SELECT
    time,
    real_client_ip,
    http_user_agent
  ORDER by
    time desc
  LIMIT
    10

• Query the number of days (days_passed) that have elapsed since an attack on the your_domain_name website was blocked by WAF. The value of days_passed is rounded to one decimal place.

  matched_host: your_domain_name
  and final_action: block |
  SELECT
    time,
    round((to_unixtime(now())-__time__) / 86400, 1) as "days_passed",
    real_client_ip,
    http_user_agent
  ORDER by
    time desc
  LIMIT
    10

• Query the trend of the number of attacks on the your_domain_name website by day.

  matched_host: your_domain_name
  and final_action: block |
  SELECT
    date_trunc('day', __time__) as dt,
    count(1) as PV
  GROUP by
    dt
  ORDER by
    dt

  The date_trunc function is used to group the time when attacks occurred by day. For more information about the function, see Date and time functions.
• Query the breakdown of countries from which attacks are launched to the your_domain_name website.

  matched_host: your_domain_name
  and final_action: block |
  SELECT
    ip_to_country(
      if(real_client_ip = '-', remote_addr, real_client_ip)
    ) as country,
    count(1) as "Number of attacks"
  GROUP by
    country

  The real_client_ip field in WAF logs indicates the originating IP address of a client. If a proxy server is used or the IP field in a request header is invalid, the originating IP address of the client cannot be obtained. In this case, the value of the real_client_ip field is displayed as a hyphen -. You can use the value of the remote_addr field as the originating IP address of the client. The remote_addr field indicates the IP address that is used to connect to WAF.
• Query the breakdown of provinces from which attacks are launched to the your_domain_name website.

  matched_host: your_domain_name
  and final_action: block |
  SELECT
    ip_to_province(
      if(real_client_ip = '-', remote_addr, real_client_ip)
    ) as province,
    count(1) as "Number of attacks"
  GROUP by
    province

  The ip_to_province function is used to obtain information about the provinces in which the originating IP addresses of clients are located. For more information about the function, see IP functions.