Hello.
I recently was having some timeout issues while updating counters and turned on
row cache for that particular CF. This is its stats:
Column Family: UserQuotas
SSTable count: 3
Space used (live): 2687239
Space used (total): 2687239
Number of Keys (estimate): 22912
Memtable Columns Count: 25766
Memtable Data Size: 180975
Memtable Switch Count: 17
Read Count: 356900
Read Latency: 1.004 ms.
Write Count: 548996
Write Latency: 0.045 ms.
Pending Tasks: 0
Bloom Filter False Postives: 17
Bloom Filter False Ratio: 0.00000
Bloom Filter Space Used: 44232
Compacted row minimum size: 125
Compacted row maximum size: 770
Compacted row mean size: 308
Since it is rather small I was hoping that it would eventually be all cached,
and the timeouts would go away. I'm updating the counters with a CL of ONE, so
I thought that the timeout would be caused by the read step and the cache would
help here. But I still get timeouts, and the cache hit rate is rather low:
Row Cache : size 1436291 (bytes), capacity 524288000 (bytes), 125310
hits, 442760 requests, 0.247 recent hit rate, 0 save period in seconds
Am I assuming something wrong about the row cache? Isn't it updated when a
counter update occurs or is just invalidated?
Best regards,
André Cruz
