Orion... should we believe what we see?
- From: "Tornblad, John" <JTornblad@xxxxxxxxxx>
- To: "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 25 Feb 2013 00:34:16 +0000
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 @ 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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