Monday, November 09, 2015

Links of the day 09/11/2015 : workload resources management and ACID in memory DB


  • Quantiles Threshold : How to determine the best threshold for your alarms using quantiles. Interesting, however the following paper tend to argue that this approach is fine until the system get close to maximum capacity.
  • Percentile-Based Approach to Forecasting Workload Growth : this paper explains the issue when the resource utilization gets closer to the workload-carrying capacity of the resource, upper percentiles level off (the phenomenon is colloquially known as flat-topping or clipping), leading to under predictions of future workload and potentially to undersized resources. They analyse the problem and propose a new approach that can be used for making useful forecasts of workload when historical data for the forecast are collected from a resource approaching saturation.
  • MemDB :  ACID compliant distributed in memory database. The performance are interesting as they deliver ACID transaction at 25k/s per shard (essentially per core). While not fantastically fast when you take a "simple"12 core server you could potentially run 250k/s transactions per system. Rapidly you can see that you can reach 1M+/s transactions with a small setup. However I would still query the need for a pure in memory ACID without persistence.. I would be curious to see if anybody has any use case for it.