Help Center/ Elastic Load Balance/ User Guide (ME-Abu Dhabi Region)/ Access Logging
Updated on 2022-01-25 GMT+08:00
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Access Logging

Scenarios

Access logs record HTTP and HTTPS requests to your load balancer in detail, such as request time, client IP address, request path, and server response. To enable access logging, you need to interconnect ELB with LTS and create a log group and log stream on the LTS console. After access logging is enabled, requests in new connections are recorded as logs, which are then uploaded to an AOM log bucket.

Configure Access Logging

  1. Create a log group.
    1. Log in to the management console.
    2. In the upper left corner of the page, click and select the desired region and project.
    3. Click Service List. Under Management & Deployment, click Log Tank Service.

    1. In the navigation pane on the left, choose Log Management.
    2. Click Create Log Group. In the displayed dialog box, enter a name for the log group.
    1. Click OK.
  2. Create a log stream.
    1. Locate the newly created log group and click its name.
    2. Click Create Log Stream. In the displayed dialog box, enter a name for the log stream.
    1. Click OK.
  3. To display access logs in real time, you need to configure the search function for the log stream.
    1. Locate the newly created log stream and click Search in the Operation column.

    1. On the displayed page, enter the search criteria as prompted.
    2. Click the search icon.
  4. Configure access logging.
    1. Click Service List. Under Network, click Elastic Load Balance.
    2. Locate the target load balancer and click its name.
    3. Under Access Logs, click Configure Access Log.

    1. Enable access logging and select the created log group and log stream.
    2. Click OK.

View Access Logs

After you enable access logging, you can obtain details about requests sent to your load balancer.

There are two ways for you to view access logs.

  1. On the ELB console, click the name of the target load balancer and click Access Logs to view logs.
  2. (Recommended) On the LTS console, click the name of the corresponding log stream. On the displayed page, click Real-Time Logs

The following is an example log. For details about the fields in the log, see Table 1.

$msec $access_log_topic_id [$time_iso8601] $log_ver $remote_addr:$remote_port $status "$request_method $scheme://$host$router_request_uri $server_protocol" $request_length $bytes_sent $body_bytes_sent $request_time "$upstream_status" "$upstream_connect_time" "$upstream_header_time" "$upstream_response_time" "$upstream_addr" "$http_user_agent" "$http_referer" "$http_x_forwarded_for" $lb_name $listener_name $listener_id
$pool_name "$member_name" $tenant_id $eip_address:$eip_port "$upstream_addr_priv" $certificate_id $ssl_protocol $ssl_cipher $sni_domain_name $tcpinfo_rtt
Table 1 Parameter description

Parameter

Description

msec

Time in seconds with a milliseconds resolution

access_log_topic_id

Log stream ID

time_iso8601

Local time in the ISO 8601 standard format

log_ver

Log format version

remote_addr: remote_port

IP address and port number of the client

status

HTTP status code

request_method scheme://host router_request_uri server_protocol

Request method Request scheme://Hostname:URI Protocol (with version)

request_length

Length of the request received from the client, including the header and body

bytes_sent

Number of bytes sent to the client

body_bytes_sent

Number of bytes sent to the client (excluding the response header)

request_time

Request processing time in seconds, that is, the duration from the time when the load balancer receives the first request packet from the client to the time when the load balancer sends the response packet

upstream_status

Response status code returned by the backend server

  • When the load balancer attempts to retry a request, there will be multiple response status codes.
  • If the request is not correctly routed to the backend server, a hyphen (-) is displayed as a null value for this field.

upstream_connect_time

Time taken to receive the response header from the backend server, in seconds with a millisecond resolution

  • When the load balancer attempts to retry a request, there will be multiple connection times.
  • If the request is not correctly routed to the backend server, a hyphen (-) is displayed as a null value for this field.

upstream_header_time

Time taken to receive the response header from the backend server, in seconds, with a millisecond resolution

  • When the load balancer attempts to retry a request, there will be multiple response times.
  • If the request is not correctly routed to the backend server, a hyphen (-) is displayed as a null value for this field.

upstream_response_time

Time taken to receive the response header from the backend server, in seconds, with a millisecond resolution

  • When the load balancer attempts to retry a request, there will be multiple response times.
  • If the request is not correctly routed to the backend server, a hyphen (-) is displayed as a null value for this field.

upstream_addr

Internal IP address and port number of the backend server

This field can be ignored.

http_user_agent

http_user_agent in the request header received by the load balancer, indicating the system model and browser information of the client

http_referer

http_referer content in the request header received by the load balancer, indicating the page link of the request

http_x_forwarded_for

http_x_forwarded_for in the request header received by the load balancer, indicating the IP address of the proxy server that the request passes through

lb_name

Load balancer name in the format of loadbalancer_Load balancer ID

listener_name

Listener name in the format of listener_Listener ID

listener_id

Listener ID (This field can be ignored.)

pool_name

Backend server group name in the format of pool_backend server group ID

member_name

Backend server name in the format of member_server ID

This field is not supported yet.

tenant_id

Tenant ID

eip_address:eip_port

EIP of the load balancer and frontend port set when the listener is added

upstream_addr_priv

IP address and port number of the backend server

certificate_id

[HTTPS listener] Certificate ID used for establishing an SSL connection

This field is not supported yet.

ssl_protocol

[HTTPS listener] Protocol used for establishing an SSL connection

For a non-HTTPS listener, a hyphen (-) is displayed as a null value for this field.

ssl_cipher

[HTTPS listener] Cipher suite used for establishing an SSL connection

For a non-HTTPS listener, a hyphen (-) is displayed as a null value for this field.

sni_domain_name

[HTTPS listener] SNI domain name provided by the client during SSL handshake

For a non-HTTPS listener, a hyphen (-) is displayed as a null value for this field.

tcpinfo_rtt

TCP Round Trip Time (RTT) between the load balancer and client in microseconds

Configure Log Transfer

If you want to perform secondary analysis on access logs, you can refer to this section to transfer logs to OBS or Data Ingestion Service (DIS) for storage.

  1. Click Service List. Under Management & Deployment, click Log Tank Service.
  2. Click Log Transfer.

  3. Set the parameters based on site requirements. For details, see the Log Tank Service User Guide.