Menu
I just did the mongodb replica set configuration and all looks good. All data moved to secondary nodes properly. But when I looked at the data directory, I can see Primary have ~140G of data and at the same time secondary has only ~110G.
Did anyone come across this kind of issue while setting up the Replica Set. Is that something normal behavior?
663
A replica set is a group of mongod instances that maintain the same data set. A replica set contains several data bearing nodes and optionally one arbiter node. Of the data bearing nodes, one and only one member is deemed the primary node, while the other nodes are deemed secondary nodes.
A replica set can have up to 7 voting members. If you have an even number of voting members, deploy another data bearing voting member or, if constraints prohibit against another data bearing voting member, an arbiter.
Replica set can have only one primary node. Replica set is a group of two or more nodes (generally minimum 3 nodes are required). In a replica set, one node is primary node and remaining nodes are secondary.
MongoDB supports replica sets, which can have up to 50 nodes.
When you do an initial sync from scratch on a secondary, it writes all the data fresh. This removes padding, empty space (deleted data) etc. As a result, in that respect it is similar to running a repair.
If you ran a repair on the primary (blocking operation, only to be done if absolutely necessary), then the two would be far closer overall.
If you check the output from db.stats() you should see that the various databases have the same object count, the data directory size differences are nothing to be worried about.
91
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
