After upgrading RHEVM from 3.0 to 3.1, CPU utilization is very high and postgresql and engine-service processes are consuming a lot of CPU

Issue

• Most CPU time is spent in userspace:

00:00:01        CPU      %usr     %nice      %sys   %iowait    %steal      %irq     %soft    %guest     %idle
00:10:01        all     42.15      0.00     13.18      0.02      0.00      0.00      0.13      0.00     44.52
00:10:01          0     46.16      0.00     14.58      0.04      0.00      0.00      0.18      0.00     39.05
00:10:01          1     44.90      0.00     15.16      0.07      0.00      0.00      0.22      0.00     39.65
00:10:01          2     46.03      0.00     14.93      0.02      0.00      0.00      0.16      0.00     38.86

• And postgresql and engine-service are consuming a lot of CPU:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
ovirt     2564 36.5  7.7 10460316 1913308 ?    Ssl  May14 962:42 engine-service -server
postgres  3591 39.4  0.3 266244 87016 ?        Ss   01:00 210:17 postgres: engine engine 127.0.0.1(41104) idle
postgres  5863 37.4  0.3 265220 81100 ?        Rs   May15 305:31 postgres: engine engine 127.0.0.1(37670) SELECT
postgres  6706 34.5  0.3 271964 91284 ?        Rs   May15 600:07 postgres: engine engine 127.0.0.1(59339) SELECT
postgres  7114 35.0  0.3 267820 89144 ?        Ss   May15 436:30 postgres: engine engine 127.0.0.1(58659) idle
postgres  7216 31.7  0.3 266092 86808 ?        Ss   06:07  71:53 postgres: engine engine 127.0.0.1(50341) idle
postgres  7217 39.1  0.3 267192 87456 ?        Ss   06:07  88:39 postgres: engine engine 127.0.0.1(50342) idle