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Adrian Cole edited this page Jun 27, 2013 · 1 revision

Overview

Denominator supports weighted (load balanced) record sets. Unlike normal case, where there's only a single record set per name and type, weighted record sets must also differentiate by qualifier (ResourceRecordSet.qualifier()). This qualifier is a friendly name for the group of servers serving a fraction of traffic, such as US-West. In practice, only one weighted record set is visible to a resolver. Which is chosen corresponds to the well-known location of the subnet of the ISP in use. As such, you can think of weighted record sets as server-side profiles, which contain the policies used to serve up names conditionally based on load.

For example, consider the following tuples: [www.mysite.com CNAME US], [www.mysite.com CNAME EU], [www.mysite.com CNAME Others]. If I'm requesting the name of www.mysite.com from Comcast in San Francisco, it is very likely I'll receive the data from the US group.

Design

This design of our geo support came via issue #87. Full support was added in issue #175.

Supported Record Types

Types supported for geo configs are typically a subset of normal records. Provider.profileToRecordTypes() for key weighted indicates what is supported, and checking this value allows you to safeguard code.

Weighted Profile

ResourceRecordSet.qualifier() indicates the group name chosen by the user. ex. US-East

Weighted is a profile which indicates load sharing dns support. This type contains the following field:

  • weight: 0 to always serve the record. Otherwise, in a provider-specific range of positive numbers which differentiate the load to send to this record set vs another.

WeightedResourceRecordSetApi

optionally exposed if the provider supports it. Similar to ResourceRecordSetApi, except that name and type are ambiguous. For example, there could be a separate rrset for the CNAME www.foo.com. for US-East and US-West profiles.

supportedWeights

In some implementation, such as UltraDNS, only even number weights are supported! For highest portability, check that the weight you intend to suggest is supported.

Common commands

Create multiple CNAMEs

CNAME records can only have one value. If you are trying to round-robin across services that use CNAMEs, you will need to create a separate Weighted RRSet for each. This is commonly used for Amazon Elastic Load Balancers.

ex.

int lightest =  weightedApi.supportedWeights().first();

for (String cname : cnames) {
  weightedApi.put(ResourceRecordSet.<CNAMEData> builder()
                                               .name("srv.denominator.io.")
                                               .type("CNAME")
                                               .ttl(0)
                                               .qualifier(cname)
                                               .addProfile(Weighted.create(lightest))
                                               .add(CNAMEData.create(cname)).build());
}

Testing

In order to run tests, you'll need to pass an additional parameter describing the zone which is ok to affect to ./gradlew clean test install

Ex. to affect the zone geo.denominator.io.

-Droute53.zone=geo.denominator.io.

Unsupported

  • noResponse: queries for this record will not be answered within the regions applied
  • unconfiguredRegions: we just enumerate the territories as opposed to making a special group, so far.
  • region -> territory value portability. There are many differences between ultradns and dynect region codes. The effort to make them portable is out of scope for this pull request.

Region -> Territory value portability

The below data showcases differences in how regions are mapped in two providers denominator supports. As discussed on the [google group](discussed here https://groups.google.com/forum/#!topic/denominator-dev/slUDAD3iRUg), we've tabled attempts to make this information portable. However, this issue can be picked up later.

{
    "dynect": {
        "11": ["AG", "AI", "AN", "AW", "BB", "BL", "BM", "BS", "BZ", "CA", "CR", "CU", "DM", "DO", "GD", "GL", "GP", "GT", "HN", "HT", "JM", "KN", "KY", "LC", "MF", "MQ", "MS", "MX", "NI", "PA", "PM", "PR", "SV", "TC", "TT", "US", "VC", "VG", "VI"],
        "United States": ["al", "ak", "as", "az", "ar", "aa", "ae", "ap", "ca", "co", "ct", "de", "dc", "fm", "fl", "ga", "gu", "hi", "id", "il", "in", "ia", "ks", "ky", "la", "me", "mh", "md", "ma", "mi", "mn", "ms", "mo", "mt", "ne", "nv", "nh", "nj", "nm", "ny", "nc", "nd", "mp", "oh", "ok", "or", "pw", "pa", "pr", "ri", "sc", "sd", "tn", "tx", "ut", "vt", "vi", "va", "wa", "wv", "wi", "wy"],
        "Canada": ["ab", "bc", "mb", "nb", "nl", "nt", "ns", "nu", "on", "pe", "qc", "sk", "yt"],
        "12": ["AR", "BO", "BR", "CL", "CO", "EC", "FK", "GF", "GY", "PE", "PY", "SR", "UY", "VE"],
        "13": ["AD", "AL", "AT", "AX", "BA", "BE", "BG", "BY", "CH", "CZ", "DE", "DK", "EE", "ES", "EU", "FI", "FO", "FR", "FX", "GB", "GG", "GI", "GR", "HR", "HU", "IE", "IM", "IS", "IT", "JE", "LI", "LT", "LU", "LV", "MC", "MD", "ME", "MK", "MT", "NL", "NO", "PL", "PT", "RO", "RS", "RU", "SE", "SI", "SJ", "SK", "SM", "TR", "UA", "VA"],
        "14": ["AO", "BF", "BI", "BJ", "BW", "CD", "CF", "CG", "CI", "CM", "CV", "DJ", "DZ", "EG", "EH", "ER", "ET", "GA", "GH", "GM", "GN", "GQ", "GW", "KE", "KM", "LR", "LS", "LY", "MA", "MG", "ML", "MR", "MU", "MW", "MZ", "NA", "NE", "NG", "RE", "RW", "SC", "SD", "SH", "SL", "SN", "SO", "ST", "SZ", "TD", "TG", "TN", "TZ", "UG", "YT", "ZA", "ZM", "ZW"],
        "15": ["AE", "AF", "AM", "AP", "AZ", "BD", "BH", "BN", "BT", "CC", "CN", "CX", "CY", "GE", "HK", "ID", "IL", "IN", "IO", "IQ", "IR", "JO", "JP", "KG", "KH", "KP", "KR", "KW", "KZ", "LA", "LB", "LK", "MM", "MN", "MO", "MV", "MY", "NP", "OM", "PH", "PK", "PS", "QA", "SA", "SG", "SY", "TH", "TJ", "TL", "TM", "TW", "UZ", "VN", "YE"],
        "16": ["AS", "AU", "CK", "FJ", "FM", "GU", "KI", "MH", "MP", "NC", "NF", "NR", "NU", "NZ", "PF", "PG", "PN", "PW", "SB", "TK", "TO", "TV", "UM", "VU", "WF", "WS"],
        "17": ["AQ", "BV", "GS", "HM", "TF"],
        "Fallback": ["@@"],
        "Anonymous Proxy": ["A1"],
        "Other Country": ["O1"],
        "Satellite Provider": ["A2"]
    },
    "ultradns": {
        "Anonymous Proxy (A1)": ["Anonymous Proxy"],
        "Satellite Provider (A2)": ["Satellite Provider"],
        "Unknown / Uncategorized IPs": ["Unknown / Uncategorized IPs"],
        "United States (US)": ["Alabama", "Alaska", "Arizona", "Arkansas", "Armed Forces Americas", "Armed Forces Europe, Middle East, and Canada", "Armed Forces Pacific", "California", "Colorado", "Connecticut", "Delaware", "District of Columbia", "Florida", "Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "Undefined United States", "United States Minor Outlying Islands", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"],
        "Mexico": ["Mexico"],
        "Canada (CA)": ["Alberta", "British Columbia", "Greenland", "Manitoba", "New Brunswick", "Newfoundland and Labrador", "Northwest Territories", "Nova Scotia", "Nunavut", "Ontario", "Prince Edward Island", "Quebec", "Saint Pierre and Miquelon", "Saskatchewan", "Undefined Canada", "Yukon"],
        "The Caribbean": ["Anguilla", "Antigua and Barbuda", "Aruba", "Bahamas", "Barbados", "Bermuda", "British Virgin Islands", "Cayman Islands", "Cuba", "Dominica", "Dominican Republic", "Grenada", "Guadeloupe", "Haiti", "Jamaica", "Martinique", "Montserrat", "Netherlands Antilles", "Puerto Rico", "Saint Barthelemy", "Saint Martin", "Saint Vincent and the Grenadines", "St. Kitts and Nevis", "St. Lucia", "Trinidad and Tobago", "Turks and Caicos Islands", "U.S. Virgin Islands"],
        "Central America": ["Belize", "Costa Rica", "El Salvador", "Guatemala", "Honduras", "Nicaragua", "Panama", "Undefined Central America"],
        "South America": ["Argentina", "Bolivia", "Brazil", "Chile", "Colombia", "Ecuador", "Falkland Islands", "French Guiana", "Guyana", "Paraguay", "Peru", "South Georgia and the South Sandwich Islands", "Suriname", "Undefined South America", "Uruguay", "Venezuela, Bolivarian Republic of"],
        "Europe": ["Aland Islands", "Albania", "Andorra", "Armenia", "Austria", "Azerbaijan", "Belarus", "Belgium", "Bosnia-Herzegovina", "Bulgaria", "Croatia", "Czech Republic", "Denmark", "Estonia", "Faroe Islands", "Finland", "France", "Georgia", "Germany", "Gibraltar", "Greece", "Guernsey", "Hungary", "Iceland", "Ireland", "Isle of Man", "Italy", "Jersey", "Latvia", "Liechtenstein", "Lithuania", "Luxembourg", "Macedonia, the former Yugoslav Republic of", "Malta", "Moldova, Republic of", "Monaco", "Montenegro", "Netherlands", "Norway", "Poland", "Portugal", "Romania", "San Marino", "Serbia", "Slovakia", "Slovenia", "Spain", "Svalbard and Jan Mayen", "Sweden", "Switzerland", "Ukraine", "Undefined Europe", "United Kingdom - England, Northern Ireland, Scotland, Wales", "Vatican City"],
        "Russian Federation": ["Russian Federation"],
        "Middle East": ["Afghanistan", "Bahrain", "Cyprus", "Iran", "Iraq", "Israel", "Jordan", "Kuwait", "Lebanon", "Oman", "Palestinian Territory, Occupied", "Qatar", "Saudi Arabia", "Syrian Arab Republic", "Turkey, Republic of", "Undefined Middle East", "United Arab Emirates", "Yemen"],
        "Africa": ["Algeria", "Angola", "Benin", "Botswana", "Burkina Faso", "Burundi", "Cameroon", "Cape Verde", "Central African Republic", "Chad", "Comoros", "Congo", "Cote d\u0027Ivoire", "Democratic Republic of the Congo", "Djibouti", "Egypt", "Equatorial Guinea", "Eritrea", "Ethiopia", "Gabon", "Gambia", "Ghana", "Guinea", "Guinea-Bissau", "Kenya", "Lesotho", "Liberia", "Libyan Arab Jamahiriya", "Madagascar", "Malawi", "Mali", "Mauritania", "Mauritius", "Mayotte", "Morocco", "Mozambique", "Namibia", "Niger", "Nigeria", "Reunion", "Rwanda", "Sao Tome and Principe", "Senegal", "Seychelles", "Sierra Leone", "Somalia", "South Africa", "St. Helena", "Sudan", "Swaziland", "Tanzania, United Republic of", "Togo", "Tunisia", "Uganda", "Undefined Africa", "Western Sahara", "Zambia", "Zimbabwe"],
        "Asia": ["Bangladesh", "Bhutan", "British Indian Ocean Territory - Chagos Islands", "Brunei Darussalam", "Cambodia", "China", "Hong Kong", "India", "Indonesia", "Japan", "Kazakhstan", "Korea, Democratic People\u0027s Republic of", "Korea, Republic of", "Kyrgyzstan", "Lao People\u0027s Democratic Republic", "Macao", "Malaysia", "Maldives", "Mongolia", "Myanmar", "Nepal", "Pakistan", "Philippines", "Singapore", "Sri Lanka", "Taiwan", "Tajikistan", "Thailand", "Timor-Leste, Democratic Republic of", "Turkmenistan", "Undefined Asia", "Uzbekistan", "Vietnam"],
        "Australia / Oceania": ["American Samoa", "Australia", "Christmas Island", "Cocos (Keeling) Islands", "Cook Islands", "Fiji", "French Polynesia", "Guam", "Heard Island and McDonald Islands", "Kiribati", "Marshall Islands", "Micronesia , Federated States of", "Nauru", "New Caledonia", "New Zealand", "Niue", "Norfolk Island", "Northern Mariana Islands, Commonwealth of", "Palau", "Papua New Guinea", "Pitcairn", "Samoa", "Solomon Islands", "Tokelau", "Tonga", "Tuvalu", "Undefined Australia / Oceania", "Vanuatu", "Wallis and Futuna"],
        "Antarctica": ["Antarctica", "Bouvet Island", "French Southern Territories"]
    }
}
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