Motivation

The WiredTiger metric cursor currently returns several fixed configuration values, including:

• "maximum internal page size"
• "maximum leaf page key size"
• "maximum leaf page size"
• "maximum leaf page value size"

While these metrics can be helpful for debugging specific issues, they never change over time. However, they are recorded every minute in FTDC, leading to:

• Unnecessary CPU usage: Processing and recording static values repeatedly consumes resources unnecessarily.
• Increased FTDC output size: The repeated logging of unchanging values bloats FTDC files, increasing storage demands over time.

At present, these fixed configuration values are recorded multiple times in FTDC for various collections:

• Oplog: 1 instance
• History Store: 1 instance
• config.image_collection: 2 instances
• config.transactions: 3 instances

This results in redundant data being captured and contributes to inefficiencies. While MongoDB could attempt to filter these static values out during FTDC recording, that approach may further increase CPU utilization.

Request

Would it be possible for WiredTiger's metric cursor to exclude these fixed configuration values from its output entirely? This would prevent them from being passed to FTDC for recording and reduce both CPU usage and disk space consumption, streamlining diagnostic capture efficiency.