What Happens when Dynamic Bypass Entries in a CacheFlow Configuration Reaches the Configured Max Entries Value?

Products

• CacheFlow Appliance Software

Issue/Introduction

The recommendation for CacheFlow deployments is to enable dynamic bypass. The following is the default dynamic bypass setting; each parameter is configurable.

CF3x5#(config dynamic-bypass)view config
Dynamic Bypass Settings:
    Timeout: 60 minutes
    Max Entries: 10000
    Server Threshold: 4
    Dynamic bypass: enabled
      Asymmetric route trigger: enabled
      Non-HTTP trigger: enabled
      HTTP connect error trigger: enabled
      HTTP receive error trigger: disabled
      HTTP 5xx trigger: disabled

These value works well in most scenarios and deployments but can be tweaked to suit your needs

Resolution

When the dynamic bypass entries reaches the configured 'Max Entries', subsequent new entries will be added to the dynamic bypass list and the 'oldest entries' will be omitted. 'Oldest Entries' would be the one with the smallest Timeout value


In the example below, assuming the 'Max Entries' is 5, and a new entry is to be added, the entry for Client IP 192.168.1.8 will be omitted because it is the oldest entry in the list (23 min timeout)


CF3x5#sh proxy-services dynamic-bypass
Reason legend:
  U - User policy           A - Asymmetric route      N - Non-HTTP
  C - Connect error         R - Receive error         5 - 5xx

Client IP address  Server IP address Timeout (minutes) Use Count Reasons
192.168.1.5           1.1.1.1                    59                         3                A
192.168.1.6           2.2.2.2                    47                         30              C
192.168.1.7           3.3.3.3                    55                         10              N
192.168.1.8           4.4.4.4                    23                         100            N <---- This entry will be omitted to make way for a new entry
192.168.1.9           5.5.5.5                    33                         5                A