TechPrufer
Get started
Cloudflare
Cloudflare logoCloudflare · Feature trail

Memory Allocator Optimization

1 post · Feb 2021

What this trail covers

Cloudflare has optimized memory usage by switching from glibc malloc to TCMalloc for services like Quicksilver, which uses RocksDB. This involved understanding the fragmentation issues inherent in glibc's arena-based allocation and the benefits of TCMalloc's front-end, middle-end, and back-end design for improved memory reuse across threads. The switch resulted in a 2.5x reduction in memory consumption.

All Cloudflare trails
  1. The effect of switching to TCMalloc on RocksDB memory useThis post details the investigation into unexpected memory growth in the Quicksilver service after migrating to RocksDB. It explains the memory fragmentation issues with glibc's malloc, particularly in multithreaded applications with multiple independent arenas, and contrasts this with TCMalloc's design, which uses a middle-end to move memory between caches, significantly reducing fragmentation and improving memory reuse. The switch to TCMalloc resulted in a 2.5x reduction in memory consumption.