Re: Memory and caches

2023-11-27 Thread Jon Haddad
I haven't found chunk cache to be particularly useful. It's a fairly small cache that could only help when you're dealing with a small hot dataset. I wouldn't bother increasing memory for it. Key cache can be helpful, but it depends on the workload. I generally recommend optimizing for your

Re: Migrating to incremental repair in C* 4.x

2023-11-27 Thread Bowen Song via user
Hi Jeff, Does subrange repair mark the SSTable as repaired? From my memory, it doesn't. Regards, Bowen On 27/11/2023 16:47, Jeff Jirsa wrote: I don’t work for datastax, thats not my blog, and I’m on a phone and potentially missing nuance, but I’d never try to convert a cluster to IR by d

Re: Memory and caches

2023-11-27 Thread Bowen Song via user
Hi Sebastien, What's your goal? Improving cache hit rate purely for the sake of having a higher hit rate is rarely a good goal, because higher cache hit rate doesn't always mean faster operations. Do you have specific issues with performance? If so, can you please tell us more about it? Thi

Re: Migrating to incremental repair in C* 4.x

2023-11-27 Thread Jeff Jirsa
I don’t work for datastax, thats not my blog, and I’m on a phone and potentially missing nuance, but I’d never try to convert a cluster to IR by disabling auto compaction . It sounds very much out of date or its optimized for fixing one node in a cluster somehow. It didn’t make sense in the 4.0

Memory and caches

2023-11-27 Thread Sébastien Rebecchi
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

Re: Migrating to incremental repair in C* 4.x

2023-11-27 Thread Bowen Song via user
Hi Sebastian, It's better to walk down the path on which others have walked before you and had great success, than a path that nobody has ever walked. For the former, you know it's relatively safe and it works. The same can hardly be said for the later. You said it takes a week to run the fu