Loading...

XML

Word

Printable

JSON

Assigned Teams:

Storage Execution
Backwards Compatibility:
Fully Compatible
Steps To Reproduce:

Hide

Replica set
Workload - Hammer.mongo, insert only profile w/ write majority

%MongoD%\mongod --wiredTigerCacheSizeGB 3 --replSet EitanRs3b --dbpath f:\data\db1 --logpath h:\data\rs3primary.txt --storageEngine wiredTiger --port 5002 --setParameter enableReplSnapshotThread=true

Show
Replica set Workload - Hammer.mongo, insert only profile w/ write majority %MongoD%\mongod --wiredTigerCacheSizeGB 3 --replSet EitanRs3b --dbpath f:\data\db1 --logpath h:\data\rs3primary.txt --storageEngine wiredTiger --port 5002 --setParameter enableReplSnapshotThread=true

Environment:

2 member replica set (Windows)
db version v3.1.8-pre-
git version: 9b054f00326b23a87ba0571cbd8997b91fe5ce16

Storage size: 13 GB
Workload:

Problem:

The same workload w/ enableReplSnapshotThread=false produce significant better throughput - See compare.png

The profiler indicates high CPU as results of __wt_tree_walk function that accountable for 80.83% of the CPU time - See profiler.png

duplicates

SERVER-20174 WT snapshot threads significantly impact performance