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
62
Good Test, Bad Test
dcrosta
1
730
Exploring Python Code Objects (PyOhio)
dcrosta
4
310
Python Packaging for Humans
dcrosta
13
500
Exploring Python Code Objects
dcrosta
5
270
Keystone: Python Web Development, Simplified
dcrosta
4
320
MongoDB In the Cloud with Amazon EC2
dcrosta
6
440
Evolution without Migration
dcrosta
2
430
Other Decks in Technology
See All in Technology
2025-10-09_プロジェクトマネージャーAIチャンス
taukami
0
140
Geospatialの世界最前線を探る [2025年版]
dayjournal
1
220
Git in Team
kawaguti
PRO
3
370
能登半島地震において デジタルができたこと・できなかったこと
ditccsugii
0
190
AWS Top Engineer、浮いてませんか? / As an AWS Top Engineer, Are You Out of Place?
yuj1osm
2
210
20251014_Pythonを実務で徹底的に使いこなした話
ippei0923
0
190
大規模サーバーレスAPIの堅牢性・信頼性設計 〜AWSのベストプラクティスから始まる現実的制約との向き合い方〜
maimyyym
9
4.6k
AWS IoT 超入門 2025
hattori
0
340
[Codex Meetup Japan #1] Codex-Powered Mobile Apps Development
korodroid
2
750
Introduction to Sansan Meishi Maker Development Engineer
sansan33
PRO
0
310
Claude Codeを駆使した初めてのiOSアプリ開発 ~ゼロから3週間でグローバルハッカソンで入賞するまで~
oikon48
7
1.8k
AI Agent Dojo #2 watsonx Orchestrateフローの作成
oniak3ibm
PRO
0
120
Featured
See All Featured
Music & Morning Musume
bryan
46
6.8k
Bootstrapping a Software Product
garrettdimon
PRO
307
110k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
53k
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
30
2.9k
Designing for Performance
lara
610
69k
Typedesign – Prime Four
hannesfritz
42
2.8k
Rails Girls Zürich Keynote
gr2m
95
14k
Principles of Awesome APIs and How to Build Them.
keavy
127
17k
Building Adaptive Systems
keathley
44
2.8k
Designing Experiences People Love
moore
142
24k
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
189
55k
How GitHub (no longer) Works
holman
315
140k
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