master: Use difference between racks to calculate distance #523
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Hi, |
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Looking at the review, would it make sense to convert the return value to uint32_t to give a wider range of distances (while obviously adding in the overflow checks as well)? |
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Yes, I think it makes sense, especially that this distance value is stored as uint32_t anyway |
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Ok, I've updated it and I think I've got the overflow checks right. |
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Thanks for linking #269 and happy to see the code work. |
This commit fixes high cpu usage in fs_periodic_file_test. Fixes lizardfs#547 Change-Id: Ia93173dd0f358f3ff606c7ebb5848f2b786b2158
This commit adds missing initialization of load_factor member to avoid valgrind warnings. Change-Id: Ifca5ad0afd781c6fc23090206750a6fe66573f10
Currently distance is calculated as 0 (same machine), 1 (same rack) and 2 (different racks). This doesn't allow any way of saying that rack 1 is closer to rack 2 than it is to rack 42. This patch changes the topology distance calculation by having different racks represented by the difference between the racks + 1 (since a distance of 1 means they're on the same rack). Rack 2 now has a distance of 2 from rack 1 (abs(2-1)+1=2) and a distance of 41 from rack 42 (abs(2-42)+1=41), which means clients on rack 2 will far prefer chunk servers on rack 1. Signed-off-by: Jonathan Dieter <jdieter@lesbg.com>
We use 64-bit version of std::min to make sure we don't overflow, but make sure it's <= max for uint32_t, then cast to uint32_t. Signed-off-by: Jonathan Dieter <jdieter@lesbg.com>
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Hi, The feature would be quite appreciated here. Do you have any plan to commit this patch any time soon? Thanks! |
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Currently distance is calculated as 0 (same machine), 1 (same rack) and 2
(different racks). This doesn't allow any way of saying that rack 1 is
closer to rack 2 than it is to rack 42.
This patch changes the topology distance calculation by having different
racks represented by the difference between the racks + 1 (since a
distance of 1 means they're on the same rack).
Rack 2 now has a distance of 2 from rack 1 (abs(2-1)+1=2) and a distance
of 41 from rack 42 (abs(2-42)+1=41), which means clients on rack 2 will
prefer chunk servers on rack 1.
The implementation idea came from #269 (comment)
I've built and tested this patch on our local 3.10.6 cluster, and it functions as advertised.
Signed-off-by: Jonathan Dieter jdieter@lesbg.com