Mastering MongoDB - Faster elections during rolling maintenance

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The maintenance/upgrade in a MongoDB replica set is typically performed in a rolling fashion. Rolling maintenance requires you to perform the maintenance on one Secondary at a time with the Primary member to go through the maintenance last. When you stepDown the Primary, all the eligible Secondaries will hold an election for a new Primary. Until a new primary is elected the database is not available for writes. This article discusses the rolling maintenance, implications of not having a Primary, the steps required to elect a new. Primary is the only member in the replica set that receives write operations.