This topic provides an overview of the access log feature of Server Load Balancer (SLB). By analyzing the access logs, you can understand the activities and geographical distribution of client users and troubleshoot issues.


You can activate the access log feature of SLB to record detailed information of all requests sent to SLB instances, including the time when requests are sent, client IP addresses, processing latency, request URIs, and server responses. As an Internet access point, SLB distributes a large number of access requests. You can use access logs to analyze the activities and geographical distribution of client users and troubleshoot issues.

After activating SLB access logs, you can store access logs in the Logstore of Alibaba Cloud Log Service for log collection and analysis. You can disable the access log feature for one or more SLB instances at any time.

No extra fee is charged for SLB access logs. You only need to pay for Log Service.

  • The access log feature can only be applied to Layer 7 load balancing. This feature is available in all regions.
  • Make sure that the HTTP header value does not contain ||. Otherwise, the exported logs may be misplaced.


SLB access logs have the following advantages:

  • Simple log processing

    Free developers and maintenance staff from tedious and time-consuming log processing so that they can concentrate on business development and technical research.

  • Cost-effective

    Access logs of SLB generate a large amount of data that needs to be processed. Therefore, you must consider performance and cost issues for log processing. Log Service analyzes 100 million logs in one second and has obvious cost advantages compared with open source solutions.

  • Real-time

    Scenarios such as DevOps, monitoring, and alerting require real-time log data. Traditional methods cannot meet this requirement. For example, performing ETL in Hive requires a long processing time, during which considerable work is required for data integration. The access log feature of SLB, integrated with the powerful big data computing capability of Alibaba Cloud Log Service, provides real-time data processing within seconds.

  • Flexible

    You can enable or disable the access log feature for selected SLB instances. Additionally, you can set the storage period (1 to 365 days) as needed and the Logstore's capacity is scalable to meet increasing service demands.