If you read my last post, you now know how to get a valid JSON output from your MongoDB shell.
But raw JSON is often useless in your scripts because you have to manipulate it to extract only the information you need.
For this purpose, I personalty use a free tool called “jq“. It is very powerful and has many advanced features. I will only show you some basic concepts that will allow you to simply deal with JSON data in your scripts.
Today, I will show you how to easily deal with MongoDB shell output in your shell (bash, ksh, …) scripts.
For readybility purpose, this topic will be divided into 2 posts. This part will focus on how to produce valid JSON output from your MongoDB shell using the “–eval” option. Second part will focus on how to use “jq” to manipulate JSON data.
One of the most important tasks for maintaining good performance in a sharded MongoDB cluster is to ensure optimal chunk distribution across each cluster member.
I’m not going to talk about picking a good shard key for your collections because the MongoDB documentation on the subject is pretty good. But I will share with you a script that I use to get the chunk distribution for all databases on a MongoDB sharded cluster.
Continue reading “Get chunk distribution for all databases in a MongoDB cluster”
