A client released a new version of their website onto 20 AWS m1.medium instances (current site at peak load runs approximately 60 m1.medium webservers).
It was clearly an unsuccessful release, but what was surprising was the system did not actually crash, it was effectively a meltdown, but servers were still operational with load averages > 100. I was impressed with the ability for Linux to still (just) function.
parallel-ssh -o StrictHostKeyChecking=no -o ConnectTimeout=5 -i -h <servers> uptime 18:01:00 up 18:44, 0 users, load average: 104.26, 110.03, 113.12 18:01:00 up 18:56, 1 user, load average: 62.33, 87.75, 90.40 18:01:03 up 18:44, 0 users, load average: 105.28, 115.33, 115.61 18:01:03 up 18:44, 0 users, load average: 149.35, 155.74, 133.68 18:01:03 up 18:51, 0 users, load average: 124.63, 121.31, 115.91 18:01:03 up 18:44, 0 users, load average: 118.99, 109.92, 110.60 18:01:04 up 18:44, 0 users, load average: 121.73, 118.40, 113.50 18:01:04 up 18:44, 0 users, load average: 113.89, 120.56, 114.64 18:01:05 up 18:44, 0 users, load average: 119.30, 119.71, 115.65 18:01:05 up 18:44, 0 users, load average: 126.33, 120.33, 119.02 18:01:05 up 18:44, 0 users, load average: 117.47, 113.01, 112.84 18:01:05 up 18:44, 0 users, load average: 172.21, 158.62, 135.19 18:01:05 up 18:44, 0 users, load average: 115.81, 114.96, 116.18 18:01:05 up 18:44, 0 users, load average: 122.25, 115.32, 115.27 18:01:05 up 18:44, 0 users, load average: 164.13, 168.04, 153.03 18:01:05 up 18:44, 0 users, load average: 123.80, 114.94, 110.29 18:01:06 up 18:44, 0 users, load average: 173.64, 173.80, 158.76 18:01:06 up 18:44, 0 users, load average: 132.52, 140.94, 135.43 18:01:06 up 18:44, 0 users, load average: 166.17, 151.68, 135.23 18:01:06 up 18:44, 0 users, load average: 170.14, 164.03, 145.31
The AWS m1.medium is a single CPU instance.
$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz stepping : 7 cpu MHz : 1800.000 cache size : 20480 KB fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae cx8 cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm up rep_good aperfmperf unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 x2apic popcnt aes hypervisor lahf_lm arat epb xsaveopt pln pts dts bogomips : 3600.00 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: