Differences between version 39 and revision by previous author of PgBench.
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| Newer page: | version 39 | Last edited on Tuesday, June 20, 2006 12:25:14 am | by GuyThornley | Revert |
| Older page: | version 17 | Last edited on Thursday, June 15, 2006 8:22:56 pm | by AristotlePagaltzis | Revert |
@@ -1,5 +1,5 @@
-This is a scratch pad for some [PostgreSQL] benchmarks. The contributed utility <tt>pgbench</tt> is used for the testing.
+This is a scratch pad for some [PostgreSQL] 8.0
benchmarks. The contributed utility <tt>pgbench</tt> is used for the testing.
For most of the testing, important parts of the [PostgreSQL] configuration used are:
<verbatim>
shared_buffers = 23987
@@ -18,13 +18,15 @@
default_with_oids = off
stats_start_collector = false
</verbatim>
-Exceptions will be listed
as the tests are performed.
+Exceptions are noted
as the tests are performed.
-The <tt>pgbench</tt> test database was created with the <tt>-s100
</tt> scale factor option. This results in a fresh database of about 1.4GB. Consecutive runs
of <tt>pgbench</tt> grow the database, however
. All
test runs were executed with the <tt>-c100</tt> option for 100 connections. The transactions per connection
was adjusted as needed
to give
a stable test result, without obvious effects of caching. Typical settings were
<tt>-t100</tt> to <tt>-t1000
</tt>.
+The <tt>pgbench</tt> test database was created with the <tt>-s600
</tt> scale factor option. This results in a fresh database of about 8.6GiB, along with
1.3GiB
of WAL
. The
test database
was then backed up
to a <tt>.tar.gz
</tt> file so it could easily be restored between test runs
.
-The <tt>pgbench</tt> client was actually run over a 100Mbit, full-duplex network connection from a client machine for most
of the testing. Running <tt>pgbench</tt> remotely has not measurably degraded the performance. The client machine is a dual 3.06GHz Xeon running Linux 2.4.27.
+Each test was executed 5 times in sequence, and the median result is reported. All tests were executed with the <tt>-c100</tt> option for 100 connections. The transaction count per connection was adjusted as necessary so that each single test would span several minutes. Typical settings were <tt>-t500</tt> to <tt>-t1000</tt>.
+
+
The <tt>pgbench</tt> client was actually run over a 100Mbit, full-duplex network connection from a client machine for all
of the testing. Running <tt>pgbench</tt> remotely has not measurably degraded the performance. The client machine is a dual 3.06GHz Xeon running Linux 2.4.27. [SSL] encryption was disabled
.
The base hardware:
* [HP] DL380 G4
@@ -36,122 +38,139 @@
The base software:
* LinuxKernel 2.4.27 from [Debian]’s <tt>kernel-image-2.4.27-2-686-smp</tt> [Package]
-* Using [Ext3] with <tt>ordered</tt> data mode
+* Using [Ext3] with 128MB journal and
<tt>ordered</tt> data mode
On with the testing!
-!! Results
+__Update__: On Tue Jun 20 2006, all results were replaced with updated results. The previous test results were invalid and incomparable, due to inconsistencies and errors in the testing process.
+
+
!! Results: 4-disk configurations
* Data array: RAID5, 4x 72GB 10k RPM%%%
WAL array: On data array%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
- number of transactions per client: 100
- number of transactions actually processed: 10000
/10000
- tps = 132
.257337
(including connections establishing)
- tps = 141
.908320
(excluding connections establishing)
+ number of transactions per client: 500
+ number of transactions actually processed: 50000
/50000
+ tps = 124
.728272
(including connections establishing)
+ tps = 124
.885813
(excluding connections establishing)
</pre>
* Data array: RAID5, 4x 72GB 10k RPM%%%
WAL array: On data array%%%
Other notes: <tt>commit_delay</tt> disabled%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
- number of transactions per client: 100
- number of transactions actually processed: 10000
/10000
- tps = 135
.567199
(including connections establishing)
- tps = 146
.354640
(excluding connections establishing)
+ number of transactions per client: 500
+ number of transactions actually processed: 50000
/50000
+ tps = 129
.347747
(including connections establishing)
+ tps = 129
.517978
(excluding connections establishing)
</pre>
* Data array: RAID5, 4x 72GB 10k RPM%%%
WAL array: On data array%%%
Other notes: battery-backed write cache disabled%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
- number of transactions per client: 50
- number of transactions actually processed: 5000
/5000
- tps = 76
.678506
(including connections establishing)
- tps = 83
.263195
(excluding connections establishing)
+ number of transactions per client: 500
+ number of transactions actually processed: 50000
/50000
+ tps = 114
.885220
(including connections establishing)
+ tps = 115
.020971
(excluding connections establishing)
</pre>
* Data array: RAID5, 4x 72GB 10k RPM%%%
WAL array: On data array%%%
+ Other notes: Battery-backed write cache and <tt>commit_delay</tt> disabled%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
- number of transactions per client: 50
- number of transactions actually processed: 5000
/5000
- tps = 50
.434271
(including connections establishing)
- tps = 53
.195151
(excluding connections establishing)
+ number of transactions per client: 500
+ number of transactions actually processed: 50000
/50000
+ tps = 80
.177806
(including connections establishing)
+ tps = 80
.244181
(excluding connections establishing)
</pre>
* Data array: RAID1, 2x 72GB 10k RPM%%%
WAL array: RAID1, 2x 72GB 10k RPM%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
number of transactions per client: 1000
number of transactions actually processed: 100000/100000
- tps = 217
.737758
(including connections establishing)
- tps = 220
.277597
(excluding connections establishing)
+ tps = 131
.213838
(including connections establishing)
+ tps = 131
.309052
(excluding connections establishing)
</pre>
* Data array: RAID1+0, 4x 72GB 15k RPM%%%
- WAL array: RAID1, 2x 72GB 10k RPM
%%%
+ WAL array: On data array
%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
- number of transactions per client: 2000
- number of transactions actually processed: 200000
/200000
- tps = 409
.561669
(including connections establishing)
- tps = 414
.078634
(excluding connections establishing)
+ number of transactions per client: 1000
+ number of transactions actually processed: 100000
/100000
+ tps = 284
.662951
(including connections establishing)
+ tps = 285
.127666
(excluding connections establishing)
</pre>
-* Data array: RAID1+
, 4x 72GB 15k RPM%%%
+* Data array: RAID5
, 4x 72GB 15k RPM%%%
WAL array: On data array%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
number of transactions per client: 1000
number of transactions actually processed: 100000/100000
- tps = 325
.140579
(including connections establishing)
- tps = 330
.843403
(excluding connections establishing)
+ tps = 189
.203382
(including connections establishing)
+ tps = 189
.379783
(excluding connections establishing)
</pre>
-* Data array: RAID5
, 4x 72GB 15k RPM%%%
+* Data array: RAID1, 2x 72GB 15k RPM%%%
+ WAL array: RAID1, 2x 72GB 15k RPM%%%
+
+ <pre>
+ scaling factor: 600
+ number of clients: 100
+ number of transactions per client: 1000
+ number of transactions actually processed: 100000/100000
+ tps = 171.537230 (including connections establishing)
+ tps = 171.680858 (excluding connections establishing)
+ </pre>
+
+!! Results: 6-disk configurations
+
+* Data array: RAID1+
, 4x 72GB 15k RPM%%%
WAL array: RAID1, 2x 72GB 10k RPM%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
number of transactions per client: 1000
number of transactions actually processed: 100000/100000
- tps = 236
.721312
(including connections establishing)
- tps = 239
.738377
(excluding connections establishing)
+ tps = 340
.756686
(including connections establishing)
+ tps = 341
.404543
(excluding connections establishing)
</pre>
* Data array: RAID5, 4x 72GB 15k RPM%%%
- WAL array: On data array
%%%
+ WAL array: RAID1, 2x 72GB 10k RPM
%%%
<pre>
- scaling factor: 100
+ scaling factor: 600
number of clients: 100
number of transactions per client: 1000
number of transactions actually processed: 100000/100000
- tps = 192
.430583
(including connections establishing)
- tps = 194
.404205
(excluding connections establishing)
+ tps = 212
.377629
(including connections establishing)
+ tps = 212
.615105
(excluding connections establishing)
</pre>
* Data array: %%%
WAL array: %%%
@@ -161,11 +180,10 @@
</pre>
!!! Other observations
-* The test database started at 1.4GB, and got to at least 14GB during testing. Has this growth affected results?
* The WAL consumes large amounts of [Kernel] page cache. When moving the WAL between devices, when the old files are unlinked, 1/2 of the page cache is freed. Since the WAL is never read and written only once, this is as waste!
* The battery-backed write cache makes write performance very erratic.
-* The [HP] ~SmartArray hardware (or perhaps driver) tends to block reads while there are cached writes occuring. Large read latencies (seconds) results
. I have not yet found a way to tune this.
+* The [HP] ~SmartArray hardware (or perhaps driver) tends to block reads while there are cached writes occuring. Large read latencies (whole
seconds) result
. I have not yet found a way to tune this.
----
Part of CategoryDiskNotes
