MongoDB - resizing the oplog of replica sets

MongoDB replica sets are used to provide redundancy for MongoDB. For the replication of the data MongoDB uses the so called oplog. This oplog is a separate collection within the local database. It is capped, so the collection cannot get bigger than the configured size. This limits the amount of entries that can be stored within the collection. If the collection is full, the oldest entries will be removed. When an application fills the oplog within 35 minutes the replica set will get out of sync after 34 minutes and 59 seconds in case of a disaster event. Continue reading

MongoDB - Can we have a backup please?

This talk is about the experiences made by Jörg Müller and Stefan Rudnitzki when they improved their MongoDB backup strategy. The talk presents their current production backup strategy, the decisions they took while building it and outlines the pros and the cons of the approach.