Comments on: MongoDB: Impact-free Index Builds using Detached ReplicaSet Nodes https://www.percona.com/blog/mongodb-impact-free-index-builds-using-detached-replicaset-nodes/ Tue, 19 Nov 2019 10:13:44 +0000 hourly 1 https://wordpress.org/?v=6.5.2 By: Corrado Pandiani https://www.percona.com/blog/mongodb-impact-free-index-builds-using-detached-replicaset-nodes/#comment-10971457 Tue, 19 Nov 2019 10:13:44 +0000 https://www.percona.com/blog/?p=58979#comment-10971457 Hi Shashank, that article talks about version 2.4, The behavior described was the one unitl version 2.4. Starting from version 2.6 is like I described in the article. See the manual page for 2.6
https://docs.mongodb.com/v2.6/core/index-creation/
The article was written when the most widely used versions were 3.4 ans 3.6, and the latest stable version was 4.0.

See the 4.0 manual page:
https://docs.mongodb.com/v4.0/core/index-creation/

it states the following:
A foreground index build on a primary requires a DB lock. It replicates as a foreground index build on replica set secondaries, and the replication worker takes a global DB lock that queues reads and writes to all databases on the indexing server.
A background index build on a primary replicates as background index builds on secondaries. The replication worker does not take a global DB lock, and secondary reads are not affected.

]]> By: Shashank Gupta https://www.percona.com/blog/mongodb-impact-free-index-builds-using-detached-replicaset-nodes/#comment-10971454 Tue, 19 Nov 2019 04:53:41 +0000 https://www.percona.com/blog/?p=58979#comment-10971454 Hello, according to you
“A foreground creation on the PRIMARY is replicated as foreground on SECONDARY nodes. A background creation is replicated as background on SECONDARY nodes as well.”
but this document says otherwise
http://www.dba86.com/docs/mongo/2.4/tutorial/build-indexes-on-replica-sets.html#index-building-replica-sets
“Background index creation operations become foreground indexing operations on secondary members of replica sets. The foreground index building process blocks all replication and read operations on the secondaries while they build the index.”

]]> By: EDUARDO LEGATTI https://www.percona.com/blog/mongodb-impact-free-index-builds-using-detached-replicaset-nodes/#comment-10971081 Tue, 06 Aug 2019 11:55:30 +0000 https://www.percona.com/blog/?p=58979#comment-10971081 Hello,

What is the purpose of the disableLogicalSessionCacheRefresh parameter? Is this really nessary to set it to true?

Thanks

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