Data Modeling for Performance

Data Modeling for Performance

Mongo BoulderJanuary 21, 2010

Michael DwanSnapjoy

i’m michael dwan@michaeldwan on the twitter

the projectCompany X

application spec

• find business details (web + api)

• search by category/keyword + geo (web + api)

• update (api)

why is this interesting?

15,000,000businesses

30,000partners

100,000geo areas

2,300categories

2,000,000requests daily

24,000,000urls in sitemap

100,000,000tags

updates

• infrequent changes

• monthly updates w/ 12M monthly changes

• “zero downtime”

the problemmo’ data, mo’ problems

complexity

businesses

phone_numbers

businesses _phone_numbers

cities

states

zips

neighborhoods

businesses_neighborhoods

tags

taggings

assets

users

categories

categorizations

providers mappings

architecture

x

xx x

read performance

solr

downtime

solr getting fussy

migrations

downtime

the solution

> gem install acts_as_web_scale

a business...

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz",}

a business... has many phone numbers

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz",}

a business... has many phone numbers

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ]}

a business... has coordinates

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ]}

a business... has coordinates

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ]}

a business... has many tags

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ]}

a business... has many tags

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ]}

a business... has an address

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ]}

a business... has an address

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St" }}

belongs to?

a state

{ "_id" : ObjectId("4ce82937961552247900000f"), "name" : "Illinois", "slug" : "il", ...}

a business... belongs to a state





{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" } }}

a business... belongs to a city

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" } }}

a business... belongs to a city

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" }, "city" : { "_id" : ObjectId("4ce82abdd3dfaa10f8006faa"), "meta" : { "slug" : "portland", }, "display_name" : "Portland, OR" }, }}

a business... belongs to a zip code

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" }, "city" : { "_id" : ObjectId("4ce82abdd3dfaa10f8006faa"), "meta" : { "slug" : "portland", }, "display_name" : "Portland, OR" }, }}


{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" }, "city" : { "_id" : ObjectId("4ce82abdd3dfaa10f8006faa"), "meta" : { "slug" : "portland", }, "display_name" : "Portland, OR" }, "zip" : { "_id" : ObjectId("4ce82c29d3dfaa116b006dfa"), "display_name" : "97211" } }}

many-to-many?

a category

{ "_id" : ObjectId("4ce82e64d3dfaa16360014eb"), "name" : "Auto Glass", "slug" : "3063-auto-glass", "tags" : [ "windshields" ], ...}



a business... belongs to many categories


a business... belongs to many categories

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "tagline" : "Your trusty glass hole", "description" : "Glass repair...", "hours" : "Mon Fri 8 5", "url" : "http://acmeglasshole.biz", "phone_numbers" : [ "5035550091", "8005555456" ], "coordinates" : [ 45.559294, -122.644053 ], "tags" : [ "glass", "mirrors", "flat glass" ], "location" : { "street_address" : "2035 NE Alberta St", "state" : { "_id" : ObjectId("4ce829379615522479000026"), "meta" : { "slug" : "or" }, "display_name" : "Oregon" }, "city" : { "_id" : ObjectId("4ce82abdd3dfaa10f8006faa"), "meta" : { "slug" : "portland", }, "display_name" : "Portland, OR" }, "zip" : { "_id" : ObjectId("4ce82c29d3dfaa116b006dfa"), "display_name" : "97211" } }, "categories" : [ { "_id" : ObjectId("4ce82e50d3dfaa16360004f2"), "meta" : { "slug" : "282-glass", "tags" : [ "windows" ], }, "display_name" : "Glass" }, { "_id" : ObjectId("4ce82e64d3dfaa16360014eb"), "meta" : { "slug" : "3063-auto-glass", "tags" : [ "windshields" ], }, "display_name" : "Auto Glass" } ]}

queries & indexesknow what you want

#1 find a businessI want *that* one

find a business

// single businessdb.businesses.findOne({ _id: ObjectId("4ce838ef4a882579960001b9")})

#2 find by locationBusinesses in San Francisco, CA

find businesses by state/city/zip

// find all within statedb.businesses.find({ "location.state._id": ObjectId("4ce82937961552247900000f")})



// find all within citydb.businesses.find({ "location.city._id": ObjectId("4ce82aa0d3dfaa10f8004a95")})



// find all within citydb.businesses.find({ "location.city._id": ObjectId("4ce82aa0d3dfaa10f8004a95")})

// find all within zipdb.businesses.find({ "location.zip._id": ObjectId("4ce82b5ed3dfaa116b0026f0")})

indexes

// the indexesdb.businesses.ensureIndex({"location.city._id": 1})db.businesses.ensureIndex({"location.zip._id": 1})

skip “location.state._id” -- only 51 possibilities

1.5GBeach

#3 find by categoryBusinesses in the Auto Repair category

businesses by category

// find by category iddb.businesses.find({ "categories._id": ObjectId("4ce82e50d3dfaa16360004f2")})

// the indexdb.businesses.ensureIndex({ "categories._id":1})

#4 - find by category + location Businesses in the Plumbing category in Chicago, IL

businesses by category + city

// find by city id and category iddb.businesses.find({ "location.city._id": ObjectId("4ce82aa0d3dfaa10f8004a95"), "categories._id": ObjectId("4ce82e50d3dfaa16360004f2")})

which index should we use?

// city id{"location.city._id":1}

// category id{"categories._id":1}

~ or ~

we need a compound indexanswer: both suck

which order?

db.businesses.ensureIndex({ "location.city._id" : 1, "categories._id" : 1})

db.businesses.ensureIndex({ "categories._id" : 1, "location.city._id" : 1})

~ or ~

answer: cities → categories

35,000 cities & 2,500 categories

create one for zip codes and categories too!

don’t we have 2 indexes on city id?

answer: yes

{"location.city._id" : 1}{"location.city._id" : 1, "categories._id" : 1}

db.businesses.dropIndex("location.city._id_1")

#5 - find by keyword“something awesome” in Boulder, CO

find businesses in city by keyword

{ "_id" : ObjectId("4ce838ef4a882579960001b9"), "name" : "Acme Glass Co", "keywords" : [ "glass", "repair", "acme", ... ]}

db.businesses.ensureIndex({ "location.city._id":1, "keywords":1})

db.businesses.find({ "location.city._id":ObjectId("4ce82aa0d3dfaa10f8004a95"), "keywords":/glass/i})

chat with Kyle Banker

me: we’re switching from postgres+solr to mongo

kyle: oh wow, you can replace solr with mongo?

me: with some creativity

kyle: seems like it’d still be hard to get just right

me: it works well

kyle: gotcha

i was wrong, kyle was right

I’ll never leave you again

...until MongoDB supports full text later this year:)

I

aggregationmap/reduce to the rescue

sitemapsbig list of every url

sitemaps

• xml files containing each unique url ~ 24M

• 50,000 urls per file, about 500 files

• urls are generated from live data

• http://companyx.com/sitemaps/1.xml

partition by consistent hash

>> "hello!".hash % 6 #=> 5

>> "/ny/new-york/c/apartments".hash % 6 #=> 5

returns an integer between 0 and the number specified

map/reduce

1. map each url in the site to a partition

2. reduce all partitions to a single document containing all urls in that partition

3. save to a permanent collection

map

/il/chicago/c/pizza 4/ny/new-york/c/apartments 1nd/rugby/c/apartments 6/14076500-bayside-marina 2/13401000-comtrak-logistics-inc 3/12347500-allstate-auto-insurance 1il/downers-grove/c/computer-web-design 6/1009500-heidelberg-lodges 5mn/redwood-falls/c/food-service 4/14077000-bank-of-america 5mn/savage/c/audio-visual-equipment 1...

1

2

3

4

5

6

reduce

{ "total" : 2, "urls" : [ "/12347500-allstate-auto-insurance", "/ny/new-york/c/apartments" ]}

{ "total" : 1, "urls" : [ "/mn/savage/c/audio-visual-equipment" ]}

{ "_id" : 1, "value" : { "total" : 2, "urls" : [ "/12347500-allstate-auto-insurance", "/mn/savage/c/audio-visual-equipment", "/ny/new-york/c/apartments" ] }}

usage

db.sitemaps.findOne({_id:1}).value.urls

[ "/12347500-allstate-auto-insurance", "/mn/savage/c/audio-visual-equipment", "/ny/new-york/c/apartments"]

wrap up

2 months later

115ms average response times

thank you@michaeldwan

Technology

Data Modeling for Performance