Sv: Sv: Re: Latest advice on SSD?

På onsdag 09. mai 2018 kl. 22:00:16, skrev Andreas Joseph Krogh <
andreas(at)visena(dot)com <mailto:andreas(at)visena(dot)com>>:
På tirsdag 10. april 2018 kl. 19:41:59, skrev Craig James <
cjames(at)emolecules(dot)com <mailto:cjames(at)emolecules(dot)com>>:
    On Tue, Apr 10, 2018 at 12:21 AM, Andreas Joseph Krogh <andreas(at)visena(dot)com
<mailto:andreas(at)visena(dot)com>> wrote: På tirsdag 10. april 2018 kl. 04:36:27,
skrev Craig James <cjames(at)emolecules(dot)com <mailto:cjames(at)emolecules(dot)com>>:
One of our four "big iron" (spinning disks) servers went belly up today.
(Thanks, Postgres and pgbackrest! Easy recovery.) We're planning to move to a
cloud service at the end of the year, so bad timing on this. We didn't want to
buy any more hardware, but now it looks like we have to. 
I followed the discussions about SSD drives when they were first becoming
mainstream; at that time, the Intel devices were king. Can anyone recommend
what's a good SSD configuration these days? I don't think we want to buy a new
server with spinning disks.
 
We're replacing:
  8 core (Intel)
  48GB memory
  12-drive 7200 RPM 500GB
     RAID1 (2 disks, OS and WAL log)
     RAID10 (8 disks, postgres data dir)
     2 spares
  Ubuntu 16.04
  Postgres 9.6
 
The current system peaks at about 7000 TPS from pgbench.

 
With what arguments (also initialization)?
 
 
pgbench -i -s 100 -U test
pgbench -U test -c ... -t ...

 
-c  -t     TPS
5   20000  5202
10  10000  7916
20  5000   7924
30  3333   7270
40  2500   5020
50  2000   6417

 
FWIW; We're testing
this: https://www.supermicro.nl/products/system/1U/1029/SYS-1029U-TN10RT.cfm
with 4 x Micron NVMe 9200 PRO NVMe 3.84TB U.2 in RAID-10:
 
$ pgbench -s 100 -c 64 -t 10000 pgbench
scale option ignored, using count from pgbench_branches table (100)
starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 100
query mode: simple
number of clients: 64
number of threads: 1
number of transactions per client: 10000
number of transactions actually processed: 640000/640000
latency average = 2.867 ms
tps = 22320.942063 (including connections establishing)
tps = 22326.370955 (excluding connections establishing)
 
Sorry, wrong disks; this is correct:
 
48 clients:
pgbench -s 100 -c 48 -t 10000 pgbench 
scale option ignored, using count from pgbench_branches table (100)
starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 100
query mode: simple
number of clients: 48
number of threads: 1
number of transactions per client: 10000
number of transactions actually processed: 480000/480000
latency average = 1.608 ms
tps = 29846.511054 (including connections establishing)
tps = 29859.483666 (excluding connections establishing)
 
 
64 clients:
pgbench -s 100 -c 64 -t 10000 pgbench 
scale option ignored, using count from pgbench_branches table (100)
starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 100
query mode: simple
number of clients: 64
number of threads: 1
number of transactions per client: 10000
number of transactions actually processed: 640000/640000
latency average = 2.279 ms
tps = 28077.261708 (including connections establishing)
tps = 28085.730160 (excluding connections establishing)

 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andreas(at)visena(dot)com <mailto:andreas(at)visena(dot)com>
www.visena.com <https://www.visena.com>
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