Need some help analyzing some benchmarks - Mailing list pgsql-performance
| From | Benjamin Krajmalnik |
|---|---|
| Subject | Need some help analyzing some benchmarks |
| Date | |
| Msg-id | F4E6A2751A2823418A21D4A160B689887B0E77@fletch.stackdump.local Whole thread Raw |
| Responses |
Re: Need some help analyzing some benchmarks
|
| List | pgsql-performance |
Before I deploy some new servers, I figured I would do some benchmarking.
Server is a Dual E5620, 96GB RAM, 16 x 450GB SAS(15K) drives.
Controller is an Areca 1680 with 2GB RAM and battery backup.
So far I have only run bonie++ since each cycle is quite long (writing 192GB).
My data partition is 12 drives in RAID 1+0 (2.7TB) running UFS2. Vfs.read_max has been set to 32, and no other tuning has been done.
Files system is not mounted with noatime at this point.
Below are the results:
db1# bonnie++ -d /usr/local/pgsql -c 4 -n 2:10000000:1000000:64 -u pgsql
Version 1.96 ------Sequential Output------ --Sequential Input- --Random-
Concurrency 4 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
db1.stackdump. 192G 860 99 213731 52 28518 45 1079 70 155479 34 49.9 12
Latency 10008us 2385ms 1190ms 457ms 2152ms 231ms
Version 1.96 ------Sequential Create------ --------Random Create--------
db1.stackdump.local -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
2:10000000:1000000/64 49 33 128 96 277 97 57 39 130 90 275 97
Latency 660ms 13954us 13003us 904ms 334ms 13365us
Not having anything to compare it to, I do not know if these are decent numbers or not – they are definitely slower than a similar setup which was posted recently using XFS on Linux, but I have not found anything in FreeBSD using UFS2 to compare it to. What strikes me in particular is that the write performance is higher than the read performance – I would have intuitively expected it to be the other way around.
My log partition is a RAID1, same drives. Performance follows:
Version 1.96 ------Sequential Output------ --Sequential Input- --Random-
Concurrency 4 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
db1.stackdump. 192G 861 99 117023 28 20142 43 359 23 109719 24 419.5 12
Latency 9890us 13227ms 8944ms 3623ms 2236ms 252ms
Version 1.96 ------Sequential Create------ --------Random Create--------
db1.stackdump.local -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
2:10000000:1000000/64 24 16 121 93 276 97 22 15 134 93 275 97
Latency 4070ms 14029us 13079us 15016ms 573ms 13369us
After seeing these results, I decided to download the areca cli and check the actual setup
Info from the RAID controller follows:
CLI> sys info
The System Information
===========================================
Main Processor : 1200MHz
CPU ICache Size : 32KB
CPU DCache Size : 32KB
CPU SCache Size : 512KB
System Memory : 2048MB/533MHz/ECC
Firmware Version : V1.48 2010-10-21
BOOT ROM Version : V1.48 2010-01-04
Serial Number : Y051CABVAR600825
Controller Name : ARC-1680
Current IP Address : 192.168.1.100
CLI> rsf info raid=2
Raid Set Information
===========================================
Raid Set Name : Raid Set # 001
Member Disks : 12
Total Raw Capacity : 5400.0GB
Free Raw Capacity : 0.0GB
Min Member Disk Size : 450.0GB
Raid Set State : Normal
CLI> vsf info vol=2
Volume Set Information
===========================================
Volume Set Name : ARC-1680-VOL#001
Raid Set Name : Raid Set # 001
Volume Capacity : 2700.0GB
SCSI Ch/Id/Lun : 00/00/01
Raid Level : Raid1+0
Stripe Size : 8K
Member Disks : 12
Cache Mode : Write Back
Tagged Queuing : Enabled
Volume State : Normal
===========================================
Having done this, I noticed that the stripe size is configured to 8K.
I am thinking the problem may be due to the stripe size. I had asked the vendor to set up the file system for these two arrays with 8K blocks, and I believe they may have misunderstood my request and set the stripe size to 8K. I assume increasing the stripe size will improve the performance.
What stripe sizes are you typically using? I was planning on setting it up with a 64K stripe size.
TIA,
Benjamin
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