oplog – Kristina Chodorow's Blog

Resizing Your Oplog

The MongoDB replication oplog is, by default, 5% of your free disk space. The theory behind this is that, if you’re writing 5% of your disk space every x amount of time, you’re going to run out of disk in 19x time. However, this doesn’t hold true for everyone, sometimes you’ll need a larger oplog.Continue reading “Resizing Your Oplog”

Bending the Oplog to Your Will

Part 3 of the replication internals series: three handy tricks. DIY triggers Using the oplog for crash recovery Creating non-replicated collections This is the third post in a three-part series on replication. See also parts 1 (replication internals) and 2 (getting to know your oplog). DIY triggers MongoDB has a type of query that behavesContinue reading “Bending the Oplog to Your Will”

Getting to Know Your Oplog

This is the second in a series of three posts on replication internals. We’ve already covered what’s stored in the oplog, today we’ll take a closer look at what the oplog is and how that affects your application. Our application could do billions of writes and the oplog has to record them all, but weContinue reading “Getting to Know Your Oplog”

Replication Internals

This is the first in a three-part series on how replication works. Replication gives you hot backups, read scaling, and all sorts of other goodness. If you know how it works you can get a lot more out of it, from how it should be configured to what you should monitor to using it directlyContinue reading “Replication Internals”

Choose your own adventure: MongoDB crash recovery edition

Suppose your application is happily talking to MongoDB and your laptop battery runs out. Or your server bursts into flame. Or velociraptors attack your data center. What now? To bring your server back up, read through the text until you get to a bold question. Click on the answer that best matches your situation toContinue reading “Choose your own adventure: MongoDB crash recovery edition”