Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
MongoDB Diagnostics and Performance Tuning
Search
dcrosta
January 23, 2012
Technology
3
1.7k
MongoDB Diagnostics and Performance Tuning
From MongoDB LA, January 19, 2012.
dcrosta
January 23, 2012
Tweet
Share
More Decks by dcrosta
See All by dcrosta
Let the computer write the tests
dcrosta
0
54
Good Test, Bad Test
dcrosta
1
710
Exploring Python Code Objects (PyOhio)
dcrosta
4
310
Python Packaging for Humans
dcrosta
13
500
Exploring Python Code Objects
dcrosta
5
250
Keystone: Python Web Development, Simplified
dcrosta
4
310
MongoDB In the Cloud with Amazon EC2
dcrosta
6
440
Evolution without Migration
dcrosta
2
420
Other Decks in Technology
See All in Technology
【5分でわかる】セーフィー エンジニア向け会社紹介
safie_recruit
0
24k
研究開発部メンバーの働き⽅ / Sansan R&D Profile
sansan33
PRO
3
17k
金融システムをモダナイズするためのAmazon Elastic Kubernetes Service(EKS)ノウハウ大全
daitak
0
120
令和最新版TypeScriptでのnpmパッケージ開発
lycorptech_jp
PRO
0
110
GitHub Coding Agent 概要
kkamegawa
1
1.5k
継続戦闘能⼒
sansantech
PRO
0
220
CSS polyfill とその未来
ken7253
0
140
toittaにOpenTelemetryを導入した話 / Mackerel APM リリースパーティ
cohalz
1
480
Zero Data Loss Autonomous Recovery Service サービス概要
oracle4engineer
PRO
2
7.2k
Slackひと声でブログ校正!Claudeレビュー自動化編
yusukeshimizu
3
160
AIコードエディタは開発を変えるか?Cursorをチームに導入して1ヶ月経った本音
ota1022
1
680
Things you never dared to ask about LLMs — v2
glaforge
1
490
Featured
See All Featured
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
357
30k
Keith and Marios Guide to Fast Websites
keithpitt
411
22k
What’s in a name? Adding method to the madness
productmarketing
PRO
22
3.5k
Building Adaptive Systems
keathley
41
2.6k
A designer walks into a library…
pauljervisheath
205
24k
The Illustrated Children's Guide to Kubernetes
chrisshort
48
50k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
29
1.7k
Visualization
eitanlees
146
16k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
1
77
Raft: Consensus for Rubyists
vanstee
137
7k
Learning to Love Humans: Emotional Interface Design
aarron
273
40k
Imperfection Machines: The Place of Print at Facebook
scottboms
267
13k
Transcript
Diagnostics and Performance Tuning Dan Crosta, 10gen
[email protected]
@lazlofruvous
Agenda •Tools •Performance Indicators
Speed MongoDB is a high-performance database, but how do I
know that I’m getting the best performance
TOOLS
1. mongostat
2.serverStatus > db.serverStatus(); { ! ! "host" : “MacBook.local", "version"
: "2.0.1", "process" : "mongod", "uptime" : 619052, // Lots more stats... }
3.Profiler > db.setProfilingLevel(2); { "was" : 0, "slowms" : 100,
"ok" : 1 }
3.Profiler > db.system.profile.find() { "ts" : ISODate("2011-09-30T02:07:11.370Z"), "op" : "query",
"ns" : "docs.spreadsheets", "query" : { "username": "dcrosta" }, "nscanned" : 20001, "nreturned" : 1, "responseLength" : 241, "millis" : 1407, "client" : "127.0.0.1", "user" : "" }
4.Monitoring Service • MMS: 10gen.com/try-mms • Nagios • Munin
INDICATORS
1.Slow Operations Sun May 22 19:01:47 [conn10] query docs.spreadsheets ntoreturn:100
reslen:510436 nscanned:19976 { username: “dcrosta”} nreturned:100 147ms
2.Replication Lag PRIMARY> rs.status() { "set" : "replSet", "date" :
ISODate("2011-09-30T02:28:21Z"), "myState" : 1, "members" : [ { "_id" : 0, "name" : "MacBook.local:30001", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "optime" : { "t" : 1317349400000, "i" : 1 }, "optimeDate" : ISODate("2011-09-30T02:23:20Z"), "self" : true }, { "_id" : 1, "name" : "MacBook.local:30002", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 302, "optime" : { "t" : 1317349400000, "i" : 1 }, "optimeDate" : ISODate("2011-09-28T10:17:47Z"), "lastHeartbeat" : ISODate("2011-09-30T02:28:19Z"),
3.Resident Memory > db.serverStatus().mem { "bits" : 64, // Need
64, not 32 "resident" : 7151, // Physical memory "virtual" : 14248, // Files + heap "mapped" : 6942 // Data files
3.Resident Memory > db.stats() { "db" : "docs", "collections" :
3, "objects" : 805543, "avgObjSize" : 5107.312096312674, "dataSize" : 4114159508, // ~4GB "storageSize" : 4282908160, // ~4GB "numExtents" : 33, "indexes" : 3, "indexSize" : 126984192, // ~126MB "fileSize" : 8519680000, // ~8.5GB "ok" : 1 }
3.Resident Memory ! ! indexSize + dataSize <= RAM
4.Page Faults > db.serverStatus().extra_info { ! "note" : "fields vary
by platform", ! “heap_usage_bytes” : 210656, ! “page_faults” : 2381 }
5.Write Lock Percentage > db.serverStatus().globalLock { "totalTime" : 2809217799, "lockTime"
: 13416655, "ratio" : 0.004775939766854653, }
Concurrency • One writer or many readers • Global RW
Lock • Yields on long-running ops and if we’re likely to go to disk.
High Lock Percentage? You’re Probably Paging!
6.Reader and Writer Queues > db.serverStatus().globalLock { "totalTime" : 2809217799,
"lockTime" : 13416655, "ratio" : 0.004775939766854653, "currentQueue" : { "total" : 1, "readers" : 1, "writers" : 0 }, "activeClients" : { "total" : 2, "readers" : 1, "writers" : 1 }
6.Reader and Writer Queues > db.currentOp() { "inprog" : [
{ "opid" : 6996, "active" : true, "lockType" : "read", "waitingForLock" : true, "secs_running" : 1, "op" : "query", "ns" : "docs.spreadsheets", "query" : { “username” : “Hackett, Bernie” }, "client" : "10.71.194.111:51015", "desc" : "conn", "threadId" : "0x152693000", "numYields" : 0 },
7.Background Flushing > db.serverStatus().backgroundFlushing { "flushes" : 5634, "total_ms" :
83556, "average_ms" : 14.830670926517572, "last_ms" : 4, "last_finished" : ISODate("2011-09-30T03:30:59.052Z") }
Disk Considerations • Raid • SSD • SAN?
8.Connections > db.serverStatus().connections { "current" : 7, "available" : 19993
}
9.Network Speed > db.serverStatus().network { "bytesIn" : 877291, "bytesOut" :
846300, "numRequests" : 9186 }
10.Fragmentation db.spreadsheets.stats() { "ns" : "docs.spreadhseets", "size" : 8200046932, //
~8GB "storageSize" : 11807223808, // ~11GB "paddingFactor" : 1.4302, "totalIndexSize" : 345964544, // ~345MB "indexSizes" : { "_id_" : 66772992, “username_1_filename_1” : 146079744, “username_1_updated_at_1” : 133111808 }, "ok" : 1 }
10.Fragmentation 2 is the Magic Number
storageSize / size > 2 • Might not be reclaiming
free space fast enough • Padding factor might not be correctly calibrated db.spreadsheets.runCommand(“compact”)
paddingFactor > 2 • You might have the wrong data
model • You might be growing documents too much • Should review Schema Design
download at mongoDB.org
We’re Hiring Engineers, Sales, Evangelist, Marketing, Support, Developers @mongodb_jobs http://linkd.in/joinmongo
We’re Always Around For Conferences, Appearances and Meetups 10gen.com/events @mongodb
h2p://bit.ly/mongo8