Cloud load balancer logs

Last update: May 27 2025

Cloud load balancer logs

For your information

Logging is available for load balancers in pools ru-2, ru-7, and ru-8.:::

The Log Platform service is used for logging the load balancer. For more information about the principle of operation and the cost of the service, see the instruction General information about the Log Platform service.

The following event types are logged for the load balancer:

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

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

To collect load balancer logs, you must enable logging for the load balancer. You can only get logs through the API.If you no longer need to collect logs, you can disable logging.

Enable logging for the load balancer⁠

You can enable logging through 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 uses some of the balancer's computational resources.

Control panel

1. In the dashboard, on the top menu, click Products and select Cloud Servers.
2. Go to Balancers → Balancers tab.
3. Open the balancer page.
4. In the Settings block, in the Logging field, click .
5. Check the Collect balancer technical logs checkbox.
6. Select a log group or create a new group. Logs from one or more balancers can be recorded in one group.
7. If you have selected a new group, enter its name.
8. Click Save.

OpenStack API

1. Get an IAM token for the project in which the balancer was created.

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

3. Open the CLI.

4. Enable logging for the 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 in which the balancer is created, for example ru-8. Address (URL) depends on the region and pool, you can look in the URL list;
   • <loadbalancer_uuid> — ID of the load balancer. You can view the ID in control panel: in the top menu click Products → Cloud Servers → Balancers → balancer page → under the balancer name, click ;
   • <x_auth_token> — The IAM token for the project you copied in step 2;
   • <log_group_name> — name of the log group where the balancer logs will be written. More information about log groups in the subsection Working principle General information about the Log Platform service.

Turn off logging for the load balancer⁠

Control panel

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

OpenStack API

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

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

3. Open the CLI.

4. Turn off logging for the 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 balancer is located, e.g. ru-8. Address (URL) depends on the region and pool, you can look in the URL list;
   • <loadbalancer_uuid> — ID of the load balancer. You can view the ID in control panel: in the top menu click Products → Cloud Servers → Balancers → balancer page → under the balancer name, click ;
   • <x_auth_token> — The IAM token for the project you copied in step 2.

Get the logs⁠

Use the Get Logs instructions in the Log Platform section.

Look at the description of the log fields for the load balancer.

Log fields⁠

Depending on the type of event, the log displays a different set of fields.

HTTP request

loadbalancer_id	Balancer ID
elapsed	Duration of request processing
url	Request URL
version	HTTP protocol version
method	HTTP method of request to the balancer
status	HTTP request response status
bytest_in	Number of bytes transferred in the request
bytes_out	Number of bytes transferred in the response to the request
backend	Balancer target group ID
client	IP address and port from which the request came
frontend	Balancer ID rules
server	Server ID in the balancer's target group
termination_state	Session state at termination, more details in the Session state at disconnection section of the HAProxy documentation
frontend_connections	Number of open connections on the balancer rule
backend_connections	Number of open connections on the balancer's target group
server_connections	Number of open connections on the server where the request was received
retries	Number of repeated request sends to the server
destination	IP address of the server where the request was received
backend_queue	Number of requests on the balancer target waiting to be executed
server_queue	Number of requests on the server waiting for execution

TCP connection

loadbalancer_id
elapsed	Duration of request processing
bytest_in	Number of bytes transferred in the request
bytes_out	Number of bytes transferred in the response to the request
backend	Balancer target group ID
client	Client IP address and port
frontend	Balancer ID rules
server	Server ID in the balancer's target group
termination_state	Session state at termination, more details in the Session state at disconnection section of the HAProxy documentation
frontend_connections	Number of open connections on the balancer rule
backend_connections	Number of open connections on the balancer's target group
server_connections	Number of open connections on the server where the request was received
destination	IP address of the server where the request was received
backend_queue	Number of requests on the target group waiting for fulfillment
server_queue	Number of requests on the server waiting for execution

Administrative event

An administrative event is a change in the status of a server in the target group.

listener_id	Balancer ID rules
loadbalancer_id	Balancer ID
status	New server status in the target group
pool_id	target group ID
member_id	Server ID in the target group