Re: Poor performance on HP Package Cluster

Your HD raw IO rate seems fine, so the problem is not likely to be
with the HDs.

That consistent ~10x increase in how long it takes to do an import or
a select is noteworthy.

This "smells" like an interconnect problem. Was the Celeron locally
connected to the HDs while the new Xeons are network
connected? Getting 10's or even 100's of MBps throughput out of
local storage is much easier than it is to do over a network. 1GbE
is required if you want HDs to push 72.72MBps over a network, and not
even one 10GbE line will allow you to match local buffered IO of
1885.34MBps. What size are those network connects (Server A <->
storage, Server B <-> storage, Server A <-> Server B)?

Ron Peacetree

At 10:16 AM 9/1/2005, Ernst Einstein wrote:

>I've set up a Package Cluster ( Fail-Over Cluster ) on our two HP
>DL380 G4 with MSA Storage G2.( Xeon 3,4Ghz, 6GB Ram, 2x 36GB(at)15rpm-
>Raid1). The system is running under Suse Linux Enterprise Server.
>
>My problem is, that the performance is very low. On our old Server (
>Celeron 2Ghz with 2 GB of Ram ) an import of our Data takes about 10
>minutes. ( 1,1GB data ). One of the DL380 it takes more than 90 minutes...
>Selects response time have also been increased. Celeron 3 sec, Xeon 30-40sec.
>
>I'm trying to fix the problem for two day's now, googled a lot, but
>i don't know what to do.
>
>Top says, my CPU spends ~50% time with wait io.
>
>top - 14:07:34 up 22 min, 3 users, load average: 1.09, 1.04, 0.78
>Tasks: 74 total, 3 running, 71 sleeping, 0 stopped, 0 zombie
>Cpu(s): 50.0% us, 5.0% sy, 0.0% ni, 0.0% id, 45.0% wa, 0.0% hi, 0.0% si
>Mem: 6050356k total, 982004k used, 5068352k free, 60300k buffers
>Swap: 2097136k total, 0k used, 2097136k free, 786200k cached
>
> PID USER PR NI VIRT RES SHR S %CPU
> %MEM TIME+COMMAND
> 9939 postgres 18 0 254m 143m 140m
> R 49.3 2.4 8:35.43 postgres:postgres plate [local]
> INSERT
> 9938 postgres 16 0 13720 1440 1120
> S 4.9 0.0 0:59.08 psql -d plate -f
> dump.sql
>10738 root 15 0 3988 1120 840
>R 4.9 0.0 0:00.05 top -d
>0.2
> 1 root 16 0 640 264 216
> S 0.0 0.0 0:05.03
> init[3]
> 2 root 34 19 0 0 0
> S 0.0 0.0 0:00.00 [ksoftirqd/0]
>
>vmstat 1:
>
>ClusterNode2 root $ vmstat 1
>procs -----------memory---------- ---swap-- -----io---- --system------cpu----
> r b swpd free buff cache si so bi bo
> in cs us sy id wa
> 1 0 0 5032012 60888 821008 0 0 216 6938 1952 5049
> 40 8 15 37
> 0 1 0 5031392 60892 821632 0 0 0 8152
> 2126 5725 45 6 0 49
> 0 1 0 5030896 60900 822144 0 0 0 8124
> 2052 5731 46 6 0 47
> 0 1 0 5030400 60908 822768 0 0 0 8144
> 2124 5717 44 7 0 50
> 1 0 0 5029904 60924 823272 0 0 0 8304
> 2062 5763 43 7 0 49
>
>I've read (2004), that Xeon may have problems with content switching
>- is the problem still existing? Can I do something to minimize the
>problem?
>
>
>postgresql.conf:
>
>shared_buffers = 28672
>effective_cache_size = 400000
>random_page_cost = 2
>
>
>shmall & shmmax are set to 268435456
>
>hdparm:
>
>ClusterNode2 root $ hdparm -tT /dev/cciss/c0d0p1
>
>/dev/cciss/c0d0p1:
>Timing buffer-cache reads: 3772 MB in 2.00 seconds = 1885.34 MB/sec
>Timing buffered disk reads: 150 MB in 2.06 seconds = 72.72 MB/sec