Lesson 6 of 14
WiredTiger in plain English: pages, cache, compression - 004
RAM 64GB unna kuda MongoDB slow ga unda? WiredTiger cache eviction ni artham chesukokapothe anthe!
Core Explanation: WiredTiger data ni Pages lo divide chestundi. Memory lo uncompress format lo, disk meeda compressed format (Snappy/Zstd) lo untundi. Dirty pages (modified data) ni checkpoint vachinappudu disk ki flush chestundi. Mee working set (frequently accessed data) RAM size kante pedda ga unte, IOPS perigi system freeze aipothundi.
Wrong Practice: Assuming more RAM solves poor indexes.
# Monitoring tools showing high 'pages read into cache'
# means your working set doesn't fit or your indexes are bad.
Best Practice: Index size ni RAM lo fit ayyela chusukondi. Keep working set < RAM.
// Check stats
db.stats().indexSize
// Compare this with available cache (default 50% of RAM - 1GB)
Closing Insight: "RAM penchadam kante mundu, indexes reduce cheyyandi. Index size eh performance ki bottleneck."