tc/jemalloc_free_memory in web beip:8040/mem_tracker is the cache size of Jemalloc. Previously lg_tcache_max:20, this will cache up to 1M Bin in the thread cache, which will cause the Jemalloc cache to be too large in some scenarios. Restore the default lg_tcache_max:16, which can cache a maximum of 64K Bins. If you are doing a performance POC, you can consider increasing it.