Case study to use MongoDB in middle-class SIer / (中規模) SIerだってMongoDBできたよ!Naruhiko Ogasawara
23 slides•8.7K views
In Japanese: 「納涼もんご祭り」のミライト情報システム(ぼくの所属企業です)のブースで流してたスライドショウです。……ちゃんと上司の許可は取りましたのでご安心を?
Case study to use MongoDB in middle-class SIer / (中規模) SIerだってMongoDBできたよ!Naruhiko Ogasawara
比べてみよう リレーショナル vs ドキュメント.pptxMariMurotani
比べてみよう リレーショナル vs ドキュメント.pptxMariMurotani
Why mincore() returns different value of stat ?Hiroaki Kubota
25 slides•1.7K views
Analyzer of MongoDB 2.4 's new feature returned ununderstandable results.
The value of "resident" totally different from "pagesInMemory".
But why ?
-"resident" are coming from STAT.
-"pageInMemory" are coming from mincore().
This slide illustrates this issue.
This document discusses ghost sync and slave delay in MongoDB replica sets. Ghost sync allows secondaries to sync from each other to improve availability when the primary is unavailable or when a secondary is catching up. Slave delay intentionally delays a secondary from syncing data from the primary for a set time period to serve as a backup in case of human errors. However, using a slave delay secondary as a ghost target is problematic as its oplog will always be delayed from the primary.
1. MongoDB's default indexing method causes performance issues as it locks the entire replica set during indexing.
2. Background indexing in newer versions may help but still risks slowing down all secondaries simultaneously.
3. The presenter suggests a manual indexing method where each secondary can index independently without affecting the others. This would distribute the indexing load and prevent replica set-wide slowdowns.
29. MongoDBのスループット
 Range fetch (10,000件 x 100)
SELECT
・MySQL
: 202 sec
*
FROM
 ・MongoDB : 3.7 sec
mytbl
WHERE
id BETWEEN 0 AND 9999;
 Range count (10,000件 x 100)
・MySQL
: 37 sec
SELECT
COUNT(*)
 ・MongoDB : 0.4 sec
FROM
mytbl
     
WHERE
id BETWEEN 0 AND 9999;