-
Notifications
You must be signed in to change notification settings - Fork 65
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
some questions about paper #1
Comments
Hi, Thanks for your interest. We modified the db_bench tool to run YCSB in RocksDB. The code of the bench is here: https://github.com/theoanab/SILK-USENIXATC2019 (tools/db_bench_tools.cc). We configured the number of injection/compaction threads to saturate the CPU (number of threads must be significantly higher than number of cores). For the ratios, we used perf. Percentages are directly what's reported by perf report. |
Hi, |
Hi,
Thank you very much~ |
1/ We measure the IO bw using iostat, and throughput directly in the systems. When IO goes up, throughput goes down. |
Yeah, thanks,write magnification is a serious matter, but the experimental setup and the benchmark in figure 3 and figure 4 is the same.They just have different experimental observation indexes(bw&throught).Because the KV-item size is1KB ,so I think the two values should be equal? |
If RocksDB has a 10x write amplification, then 1KB translate into 10KB used BW. That's what we measure (disk level bandwidth). Or am I missing something in your question? |
Yeah, thanks,Maybe I'm not making it clear. |
I am not sure to understand your question. One figure shows the throughput (requests/s), and the other one the disk usage (MB/s). The disk usage is due to RocksDB writing updates (commit log + flushing the memory component), and performing compaction. You cannot guess the throughput from the disk usage or vice versa, it is very dependant on the workloads and timings. For instance, if a key is updated twice, the disk usage will be lower than if two different keys are updated, but the throughput will be the same. Not sure what you are trying to measure here. |
Good.! Your example is very specific. I understand what you mean.That's a good idea! |
Hi,How did you experiment with bandwidth and CPU utilization for RocksDB?One more question,How is the time ratio of each step of the RocksDB in the merge process calculated? Thanks~
The text was updated successfully, but these errors were encountered: