Cloud load balancer logs

The Logs service is used for load balancer logging. For more information about how the service works and its cost, see the Logs service overview instructions. You can check the availability of the Logs service for load balancers across locations in the Logs availability by location instructions.

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

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

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

To collect load balancer logs, you need to enable logging for the load balancer. You can retrieve logs only 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, in the top menu, click Products and select Cloud Servers.
2. Go to the Load Balancers section → Load Balancers tab.
3. Open the load balancer page.
4. In the Settings block, in the Logging field, click .
5. Select the Collect load balancer technical 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. Get an IAM token for the project where the load balancer was created.

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

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. You can find the list of available pools in the Servercore infrastructure subsection of the Locations: countries, regions, availability zones, pools, and data center addresses instructions;
   • <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 that you copied in step 2;
   • <log_group_name> — name of the log group where the load balancer logs will be recorded. Learn more about log groups in the How it works subsection of the Logs service overview instructions.

Disable logging for a load balancer

Control panel

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

OpenStack API

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

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

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 is located, for example, ru-8. You can find the list of available pools in the Servercore infrastructure subsection of the Locations: countries, regions, availability zones, pools, and data center addresses instructions;
   • <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 that you copied in step 2.

Retrieve logs

Use the Get logs instructions in the Logs section.

See the description of log fields for the 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 information, see Session state at disconnection in the HAProxy 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 information, see Session state at disconnection in the HAProxy 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 the server status in the 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