Hi,
I know, this is the Trafodion user DL not a CentOS 7.x DL, but given an OS changes major versions months if not years before the next level software starts to use it, I assume Trafodion users will come looking here once CentOS 7.x is a supported version. I have had access to some prototype code that is running on CentOS 7.2. One very obvious visual change is how core assignment/usage has changed. Unfortunately it's harder to explain than it is for me to see. The internal tool I'm using shows the CPU usage of each core, for each node in the cluster. top also has a way that you can break down CPU usage per core, but even how you do that has changed a bit from 6.5 to 7.2. Having watched many Trafodion on CentOS 6.x workloads over the years every pattern is possible, but typically what you see is a downward sloping curve or straight line. That is, CPU0's usage is higher than CPU1's, which is higher than CPU2's, etc. Of course on a very busy CPU all the cores might show similar usage and in some cases there would be one or more cores that might be significantly higher than a lower numbered core. On CentOS 7.2 the pattern seems significantly different, though the throughput has been equal or better. One case I've seen multiple times on an HT-enabled node with 32 cores: 0-15 show a pattern where the even numbers cores are higher than the odd numbered cores but each set is similar in usage. Then cores 16-31 do the same, but the overall usage of each of those cores is lower than the 0-15 core. An example is below but of course it's a point in time view. As far as I know the higher level software has not changed so this would seem to be an OS-level change. The usage values from top and the internal tool agree so they seem correct. So that would imply how tasks are assigned to the cores has changed. I'm sure there is a CentOS 7 blog entry that explains this but I've not gone looking. But if anyone understands this apparent change in behavior please share so when Trafodion does support the newer OS version other users will understand the new behavior. Thanks, Dennis %Cpu0 : 51.9 us, 19.3 sy, 0.0 ni, 24.1 id, 0.0 wa, 0.0 hi, 4.7 si, 0.0 st %Cpu1 : 36.1 us, 7.8 sy, 0.0 ni, 54.1 id, 0.3 wa, 0.0 hi, 1.7 si, 0.0 st %Cpu2 : 53.8 us, 17.8 sy, 0.0 ni, 25.0 id, 0.0 wa, 0.0 hi, 3.4 si, 0.0 st %Cpu3 : 33.7 us, 9.2 sy, 0.0 ni, 55.8 id, 0.0 wa, 0.0 hi, 1.4 si, 0.0 st %Cpu4 : 52.8 us, 17.6 sy, 0.0 ni, 25.2 id, 0.0 wa, 0.0 hi, 4.5 si, 0.0 st %Cpu5 : 32.0 us, 10.7 sy, 0.0 ni, 56.0 id, 0.0 wa, 0.0 hi, 1.4 si, 0.0 st %Cpu6 : 51.9 us, 18.0 sy, 0.0 ni, 23.2 id, 0.0 wa, 0.0 hi, 6.9 si, 0.0 st %Cpu7 : 33.4 us, 9.0 sy, 0.0 ni, 56.2 id, 0.0 wa, 0.0 hi, 1.4 si, 0.0 st %Cpu8 : 51.6 us, 18.0 sy, 0.0 ni, 24.2 id, 0.0 wa, 0.0 hi, 6.2 si, 0.0 st %Cpu9 : 32.1 us, 11.0 sy, 0.0 ni, 55.9 id, 0.0 wa, 0.0 hi, 1.0 si, 0.0 st %Cpu10 : 53.2 us, 18.0 sy, 0.0 ni, 23.7 id, 0.0 wa, 0.0 hi, 5.1 si, 0.0 st %Cpu11 : 33.7 us, 10.4 sy, 0.0 ni, 54.9 id, 0.0 wa, 0.0 hi, 1.0 si, 0.0 st %Cpu12 : 52.1 us, 17.5 sy, 0.0 ni, 24.1 id, 0.0 wa, 0.0 hi, 6.3 si, 0.0 st %Cpu13 : 34.1 us, 9.5 sy, 0.0 ni, 55.1 id, 0.0 wa, 0.0 hi, 1.4 si, 0.0 st %Cpu14 : 50.3 us, 18.6 sy, 0.0 ni, 25.2 id, 0.0 wa, 0.0 hi, 5.9 si, 0.0 st %Cpu15 : 34.8 us, 9.5 sy, 0.0 ni, 54.7 id, 0.0 wa, 0.0 hi, 1.0 si, 0.0 st %Cpu16 : 45.0 us, 15.6 sy, 0.0 ni, 35.6 id, 0.0 wa, 0.0 hi, 3.8 si, 0.0 st %Cpu17 : 15.5 us, 4.7 sy, 0.0 ni, 79.4 id, 0.0 wa, 0.0 hi, 0.3 si, 0.0 st %Cpu18 : 44.7 us, 16.5 sy, 0.0 ni, 30.6 id, 0.0 wa, 0.0 hi, 8.1 si, 0.0 st %Cpu19 : 15.7 us, 4.7 sy, 0.0 ni, 78.6 id, 0.3 wa, 0.0 hi, 0.7 si, 0.0 st %Cpu20 : 41.4 us, 16.5 sy, 0.0 ni, 36.8 id, 0.0 wa, 0.0 hi, 5.3 si, 0.0 st %Cpu21 : 16.7 us, 5.1 sy, 0.0 ni, 77.5 id, 0.0 wa, 0.0 hi, 0.7 si, 0.0 st %Cpu22 : 42.9 us, 15.9 sy, 0.0 ni, 35.3 id, 0.0 wa, 0.0 hi, 5.9 si, 0.0 st %Cpu23 : 14.9 us, 5.8 sy, 0.0 ni, 79.0 id, 0.0 wa, 0.0 hi, 0.3 si, 0.0 st %Cpu24 : 45.1 us, 17.8 sy, 0.0 ni, 29.0 id, 0.0 wa, 0.0 hi, 8.0 si, 0.0 st %Cpu25 : 15.3 us, 5.0 sy, 0.0 ni, 79.3 id, 0.0 wa, 0.0 hi, 0.3 si, 0.0 st %Cpu26 : 39.8 us, 15.1 sy, 0.0 ni, 38.7 id, 0.0 wa, 0.0 hi, 6.3 si, 0.0 st %Cpu27 : 16.9 us, 5.4 sy, 0.0 ni, 77.0 id, 0.0 wa, 0.0 hi, 0.7 si, 0.0 st %Cpu28 : 45.1 us, 15.6 sy, 0.0 ni, 35.1 id, 0.0 wa, 0.0 hi, 4.2 si, 0.0 st %Cpu29 : 14.8 us, 5.7 sy, 0.0 ni, 78.2 id, 0.7 wa, 0.0 hi, 0.7 si, 0.0 st %Cpu30 : 40.9 us, 16.4 sy, 0.0 ni, 36.7 id, 0.0 wa, 0.0 hi, 6.0 si, 0.0 st %Cpu31 : 13.9 us, 5.1 sy, 0.0 ni, 80.7 id, 0.0 wa, 0.0 hi, 0.3 si, 0.0 st
