A key/value database engine which is also part of mongo 3.0
WiredTiger provides an ordered mapping from string keys to string values, columns support, transactions, async and bulk operations, custom collators, extractors and data sources.
Questions tagged [wiredtiger]
170 questions
34
votes
1 answer
mongodb impossible (?) E11000 duplicate key error dup key when upserting
My understanding is that update with upsert:true on a single document is an atomic operation so this should never result in a duplicate key error, especially not on the primary _id key, when the collection has no unique-ly indexed…
Jason
- 681
- 1
- 9
- 19
17
votes
3 answers
Mongodb can not start because of WiredTiger.turtle permissions
I am trying to start mongodb 4.0.4 on ubuntu 16.04, but the database denies all my tries. I checked mongodb log files and find out that the file named WiredTiger.turtle has no needed permissions. Here log errors:
2018-11-26T15:14:32.438+0600 E…
user3151148
- 375
- 2
- 3
- 8
16
votes
2 answers
Incorrect Count returned by MongoDB (WiredTiger)
This sounds odd, and I hope I am doing something wrong, but my MongoDB collection is returning the Count off by one in my collection.
I have a collection with (I am sure) 359671 documents. However the count() command returns 359670 documents.
I am…
James
- 2,458
- 3
- 26
- 50
9
votes
3 answers
What is the relationship between real collections' names and those in file system
I use MongoDB 3.0 with WiredTiger storage engine.
When I checked my Mongo files in dbPath, I saw the names of the files with the formats as…
tottishi05
- 557
- 1
- 5
- 13
8
votes
1 answer
Check cache size of wired tiger in a mongodb
I try to set a limit on the cache size of wiredTiger in a mongodb.
First of all, I executed the following command:
mongod --wiredTigerCacheSizeGB 1
I also added the following lines to the configuration file named mongod.conf.orig
storage:
dbPath:…
bjn
- 195
- 1
- 7
8
votes
4 answers
Docker-compose and mongoDB: Failed to start up WiredTiger under any compatibility version?
I have the following docker-compose file:
version: "3"
services:
#
# APIs
#----------------------------------------------
pokerstats:
image: pokerstats
container_name: pokerstats
ports:
-…
java12399900
- 1,485
- 7
- 26
- 56
8
votes
2 answers
MongoDB 3.0 write lock on oplog collection in replica mode
In replica mode each write operation to any collection in any DB, also writes to the oplog collection.
Now, when writing to multiple DBs in parallel, all these write operations also write to the oplog.
My question: do these write operations require…
Baruch Oxman
- 1,616
- 14
- 24
7
votes
1 answer
zstd block compression in MongoDB/Docker
I use docker-compose under Windows 10 like so:
version: '3'
services:
mongo:
image: mongo:4.2
ports:
- "27017:27017"
restart: always
volumes:
- type: bind
source: ${PWD}/mongod.conf
target:…
Jonas Byström
- 25,316
- 23
- 100
- 147
7
votes
3 answers
What are the sizes returned by `show collections`?
Edit: This question is not about vanilla MongoDB's show collections but about mongo-hacker. See accepted answer and comments.
Using Mongo DB 3.2 + WiredTiger, show collections displays two sizes: s1 / s2.
show collections
coll_1 →…
Jérôme
- 13,328
- 7
- 56
- 106
6
votes
1 answer
Does performing a partial update on a MongoDb document in WiredTiger provide any advantage over a full document update?
I'm using a Java driver, although this question is not language specific, to write partial updates to mongodb documents because using the MMAPv1 storage engine the documents are edited in place (in memory) so this provides better performance.
This…
nofunatall
- 561
- 6
- 20
5
votes
1 answer
Slow Mongo aggregate when using $sort and $limit in $facet
I am noticing huge performance differences in what appears to be same aggregate, at least conceptually. The tests were made on a simple collection structure, that has an _id and a name and a createdAt, but there 20 million of those. There is an…
Stan Wiechers
- 1,962
- 27
- 45
5
votes
1 answer
How to make MongoDB `repairDatabase` and `compact` commands work with replica-set? Downtime is ok
We need to free some of our MongoDB space, and we identified 100Gb + worth of documents that can be safely removed from a collection.
So we removed them from our test environment which has this setting:
mongodb version 3.0.1
no sharding
1 node, no…
Mario Trucco
- 1,933
- 3
- 33
- 45
5
votes
1 answer
How to remove WiredTigerStat.XX.XX files?
The are a lot of WiredTigerStat.XX.XX files in the /var/lib/mongodb/.
Can I just remove them?
mongo.conf:
systemLog:
path: /var/log/mongodb/mongod.log
destination: file
net:
bindIp: 127.0.0.1
security:
authorization: enabled
…
gronik
- 51
- 2
5
votes
2 answers
MongoDB 3.0 explain() result undocumented filter field
I run explain on the following query:
db.explain().find({ site_id:1, dimensions:[], create_date: { $gte: new Date(1452603948196) } )
The result contains a 'filter' object over the dimensions field, while it should have filtered that field using the…
Shachar
- 487
- 5
- 15
5
votes
1 answer
WiredTiger - “too many open files error” during resync of a secondary replica set member
I'm upgrading a secondary replica set member to wiredTiger. I have upgraded it from MongoDB 2.6.3 to 3.0.4 and changed the storage engine to wiredTiger. Now it is resyncing all data from the primary.
At some point the following error is received,…
Baruch Oxman
- 1,616
- 14
- 24