Tag Archives: replica set

MongoDB monitoring with mongostat

Another tool for monitoring the performance and health of a MongoDB node is mongostat. You’ll recall that mongotop shows the time in milliseconds that a mongo node spent accessing (read and write) a particular collection. mongostat on the other hand provides more detailed information about the state of a mongo node, including disk usage, data […]

Read more

MongoDB monitoring with mongotop

In the process of tuning the performance of a MongoDB replica set, it’s useful to be able to observe mongod directly, as opposed to inferring what it’s doing by watching the output of top, for example. For that reason MongoDB comes with a utility, mongotop. The output of mongotop indicates the amount of time the […]

Read more

MongoDB ReadPreference

MongoDB connections accommodate a ReadPreference, which in a clustered environment, like a replicaset, indicates how to select the best host for a query. One major consideration when setting the read preference is whether or not you can live with eventually consistent reads, since SECONDARY hosts may lag behind the PRIMARY. Some of the options you […]

Read more

MongoDB Using Replica Sets as a Backup

MongoDB implements a form of replication they call replica sets. Referring to a repica set instead of just calling it replication is a helpful distinction that becomes more obviously useful when you are introduced to sharding in MongoDB since each shard should be comprised of a set of replicas unique to that shard, but we’ll […]

Read more