Cloud load balancer logs

Load balancer logging uses the Logs service. For more details on the service principle of operation and pricing, see the Logs service overview instruction. You can check the availability of the Logs service for load balancers in regions in the Logs availability matrix.

The following types of events are logged for a load balancer:

• HTTP request;
• TCP connection;
• administrative event — change of server status in a target group.

Depending on the event type, a different set of fields is recorded.

To collect load balancer logs, you need to enable logging for the load balancer. Retrieving logs is only possible via the API. If you no longer need to collect logs, you can disable logging.

Enable logging for a load balancer

You can enable logging via the API or in the control panel — when creating a load balancer or for an existing load balancer.

Enable logging for an existing load balancer

Logging consumes some of the load balancer's computing resources.

Control panel

1. In the control panel, on the top menu, click Products and select Cloud Servers.
2. Go to Load Balancers → tab Load Balancers.
3. Open the load balancer page.
4. In the Settings block, in the Logging field, click .
5. Select the Collect technical load balancer logs checkbox.
6. Select a log group or create a new one. You can log events from one or several load balancers into the same group.
7. If you selected a new group, enter its name.
8. Click Save.

OpenStack API

1. Obtain an IAM token for the project where the load balancer was created.

2. In the response output, copy the value of X-Subject-Token.

3. Open the CLI.

4. Enable logging for the load balancer:

   curl --location --request PUT 'https://<pool>.cloud.api.selcloud.ru/load-balancer/v2/lbaas/loadbalancers/<loadbalancer_uuid>/log_offloading' \
     --header 'X-Auth-Token: <x_auth_token>' \
     --header 'Content-Type: application/json;charset=utf-8' \
     --data '{
         "log_group": "<log_group_name>"
     }

   Specify:

   • <pool> — pool where the load balancer was created, for example, ru-8. The address (URL) depends on the region and pool; you can view it in the list of URLs;
   • <loadbalancer_uuid> — load balancer ID. You can find the ID in the control panel: in the top menu, click Products → Cloud Servers → Load Balancers → load balancer page → under the load balancer name, click ;
   • <x_auth_token> — IAM token for the project, which you copied in step 2;
   • <log_group_name> — name of the log group where load balancer logs will be recorded. Learn more about log groups in the Principle of operation subsection of the Logs service overview.

Disable logging for a load balancer

Control panel

1. In the control panel, on the top menu, click Products and select Cloud Servers.
2. Go to Load Balancers → tab Load Balancers.
3. Open the load balancer page.
4. In the Settings block, in the Logging field, click .
5. Clear the Collect technical load balancer logs checkbox.
6. Click Save.

OpenStack API

1. Obtain an IAM token for the project (X-Auth-Token).

2. In the response output, copy the value of X-Subject-Token.

3. Open the CLI.

4. Disable logging for the load balancer:

   curl --location --request DELETE 'https://<pool>.cloud.api.selcloud.ru/load-balancer/v2/lbaas/loadbalancers/<loadbalancer_uuid>/log_offloading' \
     --header 'X-Auth-Token: <x_auth_token>' \
     --header 'Content-Type: application/json;charset=utf-8'

   Specify:

   • <pool> — pool where the load balancer resides, for example, ru-8. The address (URL) depends on the region and pool; you can view it in the list of URLs;
   • <loadbalancer_uuid> — load balancer ID. You can find the ID in the control panel: in the top menu, click Products → Cloud Servers → Load Balancers → load balancer page → under the load balancer name, click ;
   • <x_auth_token> — IAM token for the project, which you copied in step 2.

Retrieve logs

Use the Retrieve logs instruction in the Logs section.

See the description of log fields for a load balancer.

Log fields

Depending on the event type, different sets of fields are displayed in the log.

HTTP request

loadbalancer_id	Load balancer ID
elapsed	Request processing duration
url	Request URL
version	HTTP protocol version
method	HTTP method of the request to the load balancer
status	HTTP response status
bytest_in	Number of bytes transmitted in the request
bytes_out	Number of bytes transmitted in the response
backend	Load balancer target group ID
client	IP address and port from which the request originated
frontend	Load balancer rule ID
server	Server ID in the load balancer target group
termination_state	Session state at disconnection; for more details, see the Session state at disconnection section of the HAProxy 2.4 documentation
frontend_connections	Number of open connections for the load balancer rule
backend_connections	Number of open connections for the load balancer target group
server_connections	Number of open connections on the server that received the request
retries	Number of request retries to the server
destination	IP address of the server that received the request
backend_queue	Number of requests in the load balancer target group waiting to be processed
server_queue	Number of requests on the server waiting to be processed

TCP connection

loadbalancer_id	Load balancer ID
elapsed	Request processing duration
bytest_in	Number of bytes transmitted in the request
bytes_out	Number of bytes transmitted in the response
backend	Load balancer target group ID
client	Client IP address and port
frontend	Load balancer rule ID
server	Server ID in the load balancer target group
termination_state	Session state at disconnection; for more details, see the Session state at disconnection section of the HAProxy 2.4 documentation
frontend_connections	Number of open connections for the load balancer rule
backend_connections	Number of open connections for the load balancer target group
server_connections	Number of open connections on the server that received the request
destination	IP address of the server that received the request
backend_queue	Number of requests in the target group waiting to be processed
server_queue	Number of requests on the server waiting to be processed

Administrative event

Administrative event — change of server status in a target group.

listener_id	Load balancer rule ID
loadbalancer_id	Load balancer ID
status	New status of the server in the target group
pool_id	Target group ID
member_id	Server ID in the target group