We’ve used Compose for a number of Meteor apps over the last 2 years. It’s been simple and reliable. Recently, we decided to test one of our apps using WiredTiger storage engine on Compose. We spun up a dev server, imported the data, and ran some tests. Everything was fine except for performance.
On our classic Mongo 2.6 deployment, we have 200 MB RAM and 2 GB storage with ~1.5 GB data. The WiredTiger engine compressed the data to 333 MB and was running with 1 GB RAM. We confirmed all indexes were working, oplog was on, etc.
After running multiple performance tests, we determined that there was a significantly more latency coming from the DB with both fetching data, and making writes with the Mongo 3.2 WT setup. An email from Compose asking for advice on something we had done incorrectly in the setup prompted this response:
“Ah, we just now noticed that the new deployment is the minimum sized WiredTiger deployment. A move to WT is typically a step back in performance for most data sets and workloads, unless a ton of RAM is thrown at it, and even then there are some workloads that are just never going to see much of a speed increase at all.”
So, I wanted to start this topic as I could not find similar experiences on the meteor forums from other developers. Has anyone else noticed a decrease in performance after doing a migration to 3.2 WT? If so, were there any steps you took to fix it? Any thoughts around why this might be happening to us? Everything we read (and we are not DB engineers so we have surface level knowledge on this topic), including posts written by Compose, suggests there should be a performance pickup for most workloads with WT… wanted to open this up to the community to hear other thoughts/ experiences to see if we are missing something.
Thank you all for your input!