Hello When I use nodetool info, it prints that relevant information
Heap Memory (MB) : 14229.31 / 32688.00 Off Heap Memory (MB) : 5390.57 Key Cache : entries 670423, size 100 MiB, capacity 100 MiB, 13152259 hits, 47205855 requests, 0.279 recent hit rate, 14400 save period in seconds Chunk Cache : entries 63488, size 992 MiB, capacity 992 MiB, 143250511 misses, 162302465 requests, 0.117 recent hit rate, 2497.557 microseconds miss latency Here I focus on lines relevant for that conversation. And the numbers are roughly the same for all nodes of the cluster. The key and chunk caches are full and the hit rate is low. At the same time the heap memory is far from being used at full capacity. I would say that I can significantly increase the sizes of those caches in order to increase hit rate and improve performance. In cassandra.yaml, key_cache_size_in_mb has a blank value, so 100 MiB by default, and file_cache_size_in_mb is set to 1024. I'm thinking about setting key_cache_size_in_mb to 1024 and file_cache_size_in_mb to 2048. What would you recommend? Is anyone having good experience with tuning those parameters? Thank you in advance. Sébastien.
