Orion... should we believe what we see?
Date: Mon, 25 Feb 2013 00:34:16 +0000
Message-ID: <8A354F8DD7A2CF489BC375F536A4BF4514B1D6_at_zbnaaeex012.na.webmd.net>
We are seeing wildy varying performance in an Orion run meant to simulate a DW workload (large sequential 1MB reads).
The output below seems to be "red flags" all over:
a) Wildly varying results, even counterintuitive results (more concurrent reads = less throughput) b) Latency on the first test (1 concurrent read at a time) showed 34 IOs at a 1-2 sec latency c) In other tests, smaller reads (128KB) seem to perform better but have only yielded a maximum of ~1300 MB/sec
Trying to employ some "USE" (utilization/saturation/errors) methodology but this is time consuming. There is some skepticism of Orion's reliability in our shop. Problem statement: we believe this frame should be producing closer to 2300 MB/sec bandwidth on large sequential IOs.
Any comments regarding weirdness (or normality?) of these results, steps to take next, observations would be greatly appreciated.
Orion's documentation is a little scant and not many (any?) metalink notes regarding effectively using it. I've listened to Alex Gorbachev talk about Orion a couple of times but need more input on what to do or think when "things don't go right".
-john
$ORACLE_HOME/bin/orion -testname test -run advanced -matrix col -num_small 0 -write 0 -type seq -num_streamIO 1 -cache_size 3072 -verbose -num_disks 180 -size_large 1024 -simulate raid0 -stripe 128
Large/Small, 0 1, 43.50 2, 197.40 3, 37.75 4, 568.16 5, 24.11 6, 25.17 7, 67.05 8, 100.88 9, 63.42 10, 64.42 11, 402.35 12, 364.49 13, 76.10 14, 158.64 15, 252.41 16, 591.30 17, 574.85 18, 330.49 19, 176.74 20, 46.64 21, 118.67 22, 144.45 23, 508.20 24, 177.40 25, 185.84 26, 524.93 27, 127.82 28, 53.91 29, 80.99 30, 92.30 60, 555.11 90, 988.31 120, 1019.90 150, 1117.30 180, 1130.85 210, 1119.28 240, 1132.22 270, 1123.01 300, 1146.14 330, 1119.74 360, 1124.75 Latency Histogram for large IOs _at_ Small=0 and Large=1 Latency: # of IOs (read) # of IOs (write) 0 - 1 us: 0 0 2 - 4 us: 0 0 4 - 8 us: 0 0 8 - 16 us: 0 0 16 - 32 us: 0 0 32 - 64 us: 0 0 64 - 128 us: 0 0 128 - 256 us: 0 0 256 - 512 us: 0 0 512 - 1024 us: 0 0 1024 - 2048 us: 2515 0 2048 - 4096 us: 45 0 4096 - 8192 us: 11 0 8192 - 16384 us: 20 0 16384 - 32768 us: 20 0 32768 - 65536 us: 1 0 65536 - 131072 us: 0 0 131072 - 262144 us: 0 0 262144 - 524288 us: 0 0 524288 - 1048576 us: 2 0 1048576 - 2097152 us: 34 0 2097152 - 4194304 us: 0 0 4194304 - 8388608 us: 0 0 8388608 - 16777216 us: 0 0 16777216 - 33554432 us: 0 0 33554432 - 67108864 us: 0 0 67108864 - 134217728 us: 0 0 134217728 - 268435456 us: 0 0
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Received on Mon Feb 25 2013 - 01:34:16 CET