Application Delivery (ADX)

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New Contributor
Posts: 2
Registered: ‎04-12-2011

DNS load balancing issue with ADX

DNS Query   Result : Direct to DNS Server

DNS Query   Result : VIA ADX 1000 to DNS Server

Final   benchmark results, sorted by nameserver performance:

(average cached name retrieval speed,   fastest to slowest)

  115.167. 78.165 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.031 | 0.088 | 0.108 | 0.020 | 100.0 |

  - Uncached Name | 0.215 | 0.390 | 0.921 | 0.154 | 100.0 |

  - DotCom Lookup | 0.201 | 0.300 | 0.614 | 0.078 | 100.0 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-165.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

  115.167. 78.166 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.054 | 0.089 | 0.105 | 0.016 | 100.0 |

  - Uncached Name | 0.203 | 0.376 | 0.954 | 0.144 | 100.0 |

  - DotCom Lookup | 0.189 | 0.283 | 0.408 | 0.062 | 100.0 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-166.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

  115.167. 78.163 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.040 | 0.090 | 0.123 | 0.018 | 100.0 |

  - Uncached Name | 0.204 | 0.370 | 1.125 | 0.170 | 100.0 |

  - DotCom Lookup | 0.199 | 0.292 | 0.511 | 0.082 | 100.0 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-163.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

  115.167. 78.162 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.044 | 0.091 | 0.112 | 0.017 | 100.0 |

  - Uncached Name | 0.203 | 0.347 | 0.614 | 0.095 | 100.0 |

  - DotCom Lookup | 0.194 | 0.272 | 0.369 | 0.049 | 100.0 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-162.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

  115.167. 78.164 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.046 | 0.092 | 0.141 | 0.017 | 100.0 |

  - Uncached Name | 0.205 | 0.389 | 1.535 | 0.225 | 100.0 |

  - DotCom Lookup | 0.200 | 0.281 | 0.409 | 0.056 | 100.0 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-164.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

  UTC: 2011-04-29, from 17:15:13 to 17:15:50, for 00:36.582

Final   benchmark results, sorted by nameserver performance:

(average cached name retrieval speed,   fastest to slowest)

  115.167. 78.189 |  Min    |  Avg  |    Max  |Std.Dev|Reliab%|

    ----------------+-------+-------+-------+-------+-------+

  - Cached Name   | 0.072 | 0.100 | 0.102 | 0.006 | 94.6 |

  - Uncached Name | 0.222 | 0.338 | 0.409 | 0.052 |  54.3 |

  - DotCom Lookup | 0.214 | 0.276 | 0.307 | 0.044 | 36.8 |

    ---<-------->---+-------+-------+-------+-------+-------+

             115-167-78-189.wi-tribe.net.pk

                Wi-Tribe Pakistan Limited

    UTC: 2011-04-29, from 17:18:03 to 17:18:31, for 00:27.883

Occasional Contributor
Posts: 6
Registered: ‎05-04-2009

Re: DNS load balancing issue with ADX

Please provide more context around this issue

Contributor
Posts: 47
Registered: ‎07-14-2010

Re: DNS load balancing issue with ADX

Benchmark tools like DNSBench.exe and queryperf utility always use exactly the same source port number, 62962 for example. This is not expected in real world. source port# should be changed based on each new query. When tools make dns query using same source port, it may happen when ADX will not handle dns packet due to  fast delete mechanism.

ServerIron has mechanism called fast delete. In fast delete mode,  we delete session as soon as we receive reply message without putting session into delete queue. This makes ADX quite schalable for UDP application(dns or radius). If you want to stop fast-delete mode, then configure "port udp-normal-age" under VIP configuration. Please note that fast delete mode is a proven technology. We have huge install basis in ISPs and Root DNS servers around the world.

DNSBench.exe    http://www.GRC.com/dns/benchmark.htm

queryperf              https://www.isc.org/software/bind

Thanks.

//Kono

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