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From: Edgar Rodriguez-D. <ed...@sy...> - 2016-08-26 00:02:19
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Hi, We’ve been experimenting with analytic mode using a dataset with ~12M quads. While running a particular query, a bit complex, it produces the following running times consistently: Blazegraph version: 2.0.1 Using Java Heap Mem Configurations tried: (Xms4g, Xmx8g) Concurrency Level | Approx avg. execution time ------------------|--------------------------- 1 | 3.5 3 | 5.0 5 | 5.5 9 | 8 10 | 9 Using Analytic Mode Mem Configurations tried: (Xms2g, Xmx2g, -XX:MaxDirectMemorySize=6g), (Xms4g, Xmx4g, -XX:MaxDirectMemorySize=4g) Concurrency Level | Approx avg. execution time ------------------|--------------------------- 1 | 3.09 3 | 5.95 5 | 10.58 9 | 19.24 10 | 22.87 On levels of concurrency > 3, queries are highly penalized on performance, being at least 2x slower. I know that there may be an overhead on performance for BG doing it's own memory management, but 2x slower queries on relatively low levels of concurrency seems like a bit too high. So, the questions are: Is the previous outcome something expected or an exception?, if it's an exception I could follow up with a bug report. What can be expected on the performance of concurrent queries while on analytic mode? |