Manual Chapter : Configuring Logging of Global Server Load Balancing Decisions

Applies To:

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BIG-IP DNS

  • 14.0.1, 14.0.0

BIG-IP LTM

  • 14.0.1, 14.0.0
Manual Chapter

Configuring Logging of Global Server Load Balancing Decisions

About logging global server load-balancing decisions

When BIG-IP DNS receives a DNS query for a wide IP, in order to send a response, the system makes a load-balancing decision. The decision is based on the load-balancing method configured on the wide IP, the number of pools associated with the wide IP, and the applicable number of members in each pool.
You can send information about how BIG-IP DNS made the load-balancing decision to the high-speed remote logs; reviewing the logs can help determine how to fine-tune your network.

Configuring logs for global server load-balancing decisions

Ensure that at least one wide IP exists in the BIG-IP DNS configuration, and that high-speed remote logging is configured on the device.
When you want to view the global server load-balancing decisions made by BIG-IP DNS in the high-speed remote logs, configure the verbosity of the information that displays in the logs.
  1. On the Main tab, click
    DNS
    GSLB
    Wide IPs
    .
    The Wide IP List screen opens.
  2. Click the name of the wide IP you want to modify.
  3. From the General Properties list, select
    Advanced
    .
  4. For the
    Load-Balancing Decision Log
    setting, select the check boxes of the options that you want to include in the high-speed remote logs.
    Check-box option
    Log information
    Pool Selection
    The pool selected to answer a DNS request, and why the pool was selected.
    Pool Traversal
    The pools in the wide IP considered during the load-balancing decision, and why the pool was selected.
    Pool Member Selection
    The pool member selected to answer a DNS request, and why the member was selected.
    Pool Member Traversal
    The members of the pool considered during the load-balancing decision, and why the member was selected.
    Example log for a wide IP configured for Ratio load balancing when
    Load-Balancing Decision Log
    is set to only
    Pool Selection
    :
    2013-03-14 15:40:05 bigip1.com to 10.10.10.9#34824: [wip.test.net A] [ratio selected pool (pool_b) with the first highest ratio counter (1)]
    Example log for a wide IP configured for Ratio load balancing when
    Load-Balancing Decision Log
    is set to both
    Pool Selection
    and
    Pool Traversal
    :
    2013-03-14 16:18:41 bigip1.com from 10.10.10.9#35902 [wip.test.net A] [ratio selected pool (pool_a) - ratio counter (0) is higher] [ratio skipped pool (pool_b) - ratio counter (0) is not higher] [ratio reset IPv4 ratio counter to original ratios - the best had zero ratio count] [ratio selected pool (pool_a) - ratio counter (1) is not higher] [ratio selected pool (pool_b) - ratio counter (1) is not higher] [ratio selected pool (pool_a) with the first highest ratio counter (1)]