# Octavia Amphora Log Offloading

The default logging configuration will store the logs locally, on the amphora filesystem with file rotation.

Octavia Amphorae can offload their log files via the syslog protocol to syslog receivers via the load balancer management network (lb-mgmt-net). This allows log aggregation of both administrative logs and also tenant traffic flow logs. The syslog receivers can either be local to the load balancer management network or routable via the load balancer management network. By default any syslog receiver that supports UDP or TCP syslog protocol can be used, however the operator also has the option to create an override rsyslog configuration template to enable other features or protocols their Amphora image may support.

This guide will discuss the features of Amphora log offloading and how to configure them.

## Administrative Logs

The administrative log offloading feature of the Amphora covers all of the system logging inside the Amphora except for the tenant flow logs. Tenant flow logs can be sent to and processed by the same syslog receiver used by the administrative logs, but they are configured seperately.

All administrative log messages will be sent using the native log format for the application sending the message.

### Enabling Administrative Log Offloading

One or more syslog receiver endpoints must be configured in the Octavia configuration file to enable administrative log offloading. The first endpoint will be the primary endpoint to receive the syslog packets. Should the first endpoint become unavailable, the additional endpoints listed will be tried one at a time.

Note

Secondary syslog endpoints will only be used if the log_protocol is configured for TCP. With the UDP syslog protocol, rsyslog is unable to detect if the primary endpoint has failed.

To configure administrative log offloading, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    admin_log_targets = 192.0.2.1:10514, 2001:db8:1::10:10514

In this example, the primary syslog receiver will be 192.0.2.1 on port 10514. The backup syslog receiver will be 2001:db8:1::10 on port 10514.

Note

Make sure your syslog receiver endpoints are accessible from the load balancer management network and you have configured the required security group or firewall rules to allow the traffic. These endpoints can be routable addresses from the load balancer management network.

The load balancer related administrative logs will be sent using a LOG_LOCAL[0-7] facility. The facility number defaults to 1, but is configurable using the administrative_log_facility setting in the Octavia configuration file.

To configure administrative log facility, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    administrative_log_facility = 1

### Forwarding All Administrative Logs

By default, the Amphorae will only forward load balancer related administrative logs, such as the haproxy admin logs, keepalived, and Amphora agent logs. You can optionally configure the Amphorae to send all of the administrative logs from the Amphora, such as the kernel, system, and security logs. Even with this setting the tenant flow logs will not be included. You can configure tenant flow log forwarding in the Tenant Flow Logs section.

The load balancer related administrative logs will be sent using the LOG_LOCAL[0-7] configured using the administrative_log_facility setting. All other administrative log messages will use their native syslog facilities.

To configure the Amphorae to forward all administrative logs, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    forward_all_logs = True

## Tenant Flow Logs

### Enabling Tenant Flow Log Offloading

One or more syslog receiver endpoints must be configured in the Octavia configuration file to enable tenant flow log offloading. The first endpoint will be the primary endpoint to receive the syslog packets. Should the first endpoint become unavailable, the additional endpoints listed will be tried one at a time. The endpoints configured for tenant flow log offloading may be the same endpoints as the administrative log offloading configuration.

Warning

Tenant flow logging can produce a large number of syslog messages depending on how many connections the load balancers are receiving. Tenant flow logging produces one log entry per connection to the load balancer. We recommend you monitor, size, and configure your syslog receivers appropriately based on the expected number of connections your load balancers will be handling.

Note

Secondary syslog endpoints will only be used if the log_protocol is configured for TCP. With the UDP syslog protocol, rsyslog is unable to detect if the primary endpoint has failed.

To configure tenant flow log offloading, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    tenant_log_targets = 192.0.2.1:10514, 2001:db8:1::10:10514

In this example, the primary syslog receiver will be 192.0.2.1 on port 10514. The backup syslog receiver will be 2001:db8:1::10 on port 10514.

Note

Make sure your syslog receiver endpoints are accessible from the load balancer management network and you have configured the required security group or firewall rules to allow the traffic. These endpoints can be routable addresses from the load balancer management network.

The load balancer related tenant flow logs will be sent using a LOG_LOCAL[0-7] facility. The facility number defaults to 0, but is configurable using the user_log_facility setting in the Octavia configuration file.

To configure the tenant flow log facility, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    user_log_facility = 0

### Tenant Flow Log Format

The default tenant flow log format is:

Any field that is unknown or not applicable to the connection will have a ‘-‘ character in its place.

An example log entry when using rsyslog as the syslog receiver is:

Note

The prefix[1] in this example comes from the rsyslog receiver and is not part of the syslog message from the amphora.

[1] “Jun 12 00:44:13 amphora-3e0239c3-5496-4215-b76c-6abbe18de573 haproxy[1644]:”

### Custom Tenant Flow Log Format

You can optionally specify a custom log format for the tenant flow logs. This string follows the HAProxy log format variables with the exception of the “{{ project_id }}” and “{{ lb_id }}” variables that will be replaced by the Octavia Amphora driver. These custom variables are optional.

See the HAProxy documentation for Custom log format variable definitions.

To configure a custom log format, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [haproxy_amphora]
    user_log_format = '{{ project_id }} {{ lb_id }} %f %ci %cp %t %{+Q}r %ST %B %U %[ssl_c_verify] %{+Q}[ssl_c_s_dn] %b %s %Tt %tsc'

## Disabling Logging

There may be cases where you need to disable logging inside the Amphora, such as complying with regulatory standards. Octavia provides multiple options for disabling Amphora logging.

### Disable Local Log Storage

This setting stops log entries from being written to the disk inside the Amphora. Logs can still be sent via Amphora log offloading if log offloading is configured for the Amphorae. Enabling this setting may provide a performance benefit to the load balancer.

Warning

This feature disables ALL log storage in the Amphora, including kernel, system, and security logging.

Note

If you enable this setting and are not using Amphora log offloading, we recommend you also Disable Tenant Flow Logging to improve load balancing performance.

To disable local log storage in the Amphora, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [amphora_agent]
    disable_local_log_storage = True

### Disable Tenant Flow Logging

This setting allows you to disable tenant flow logging irrespective of the other logging configuration settings. It will take precedent over the other settings. When this setting is enabled, no tenant flow (connection) logs will be written to the disk inside the Amphora or be sent via the Amphora log offloading.

Note

Disabling tenant flow logging can also improve the load balancing performance of the amphora. Due to the potential performance improvement, we recommend you enable this setting when using the Disable Local Log Storage setting.

To disable tenant flow logging, set the following setting in your Octavia configuration file for all of the controllers and restart them:

    [haproxy_amphora]
    connection_logging = False

this page last updated: 2023-10-24 12:56:13

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