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How long does it take to set a primary in MongoDB?
The median time before a cluster elects a new primary should not typically exceed 12 seconds, assuming default replica configuration settings. This includes time required to mark the primary as unavailable and call and complete an election .
What does it mean when MongoDB is not connecting?
In short, MongoDB not connecting error happens due to failed MongoDB server, firewall restrictions, auth failure, etc. Today, we saw various methods for connecting to MongoDB and how our Support Engineers fixed MongoDB not connecting errors. PREVENT YOUR SERVER FROM CRASHING! Never again lose customers to poor server speed!
How to perform maintenance on a MongoDB replica set?
The MongoDB Documentation suggests the following to perform maintenance on a replica set member, which brings the the replica set member into standalone mode for further operations. With little modification it can be made standalone: After this, the node in concern should be up and running in standalone mode.
How to remove secondary hosts from Mongo replica set?
Remove all secondary hosts from replica set (rs.remove (‘host:port’)), restart the mongo deamon without replSet parameter (editing /etc/mongo.conf) and the secondary hosts starts in standalone mode again. The Primary host is tricky one, because you can’t remove it from the replica set with rs.remove.
What’s the change in MongoDB version 4.0?
Changed in version 4.0: MongoDB 4.0 removes the deprecated replication protocol version 0. Replication protocolVersion: 1 reduces replica set failover time and accelerate the detection of multiple simultaneous primaries.
What does mirrored reads do in MongoDB 4.4?
Starting in version 4.4, MongoDB provides mirrored reads to pre-warm electable secondary members’ cache with the most recently accessed data. With mirrored reads, the primary can mirror a subset of operations that it receives and send them to a subset of electable secondaries.
How to enable retryable writes in MongoDB 4.0?
MongoDB 4.2+ compatible drivers enable retryable writes by default MongoDB 4.0 and 3.6-compatible drivers must explicitly enable retryable writes by including retryWrites=true in the connection string. Changed in version 4.0: MongoDB 4.0 removes the deprecated replication protocol version 0.
Can you change the number of votes in a replica set?
Do not alter the number of votes to control which members will become primary. Instead, modify the members [n].priority option. Only alter the number of votes in exceptional cases. For example, to permit more than seven members. To configure a non-voting member, see Configure Non-Voting Replica Set Member.