reviewed by Greg Smith and Josh Williams.
Following is the proposal from ITAGAKI Takahiro:
Pgbench is a famous tool to measure postgres performance, but nowadays
it does not work well because it cannot use multiple CPUs. On the other
hand, postgres server can use CPUs very well, so the bottle-neck of
workload is *in pgbench*.
Multi-threading would be a solution. The attached patch adds -j
(number of jobs) option to pgbench. If the value N is greater than 1,
pgbench runs with N threads. Connections are equally-divided into
them (ex. -c64 -j4 => 4 threads with 16 connections each). It can
run on POSIX platforms with pthread and on Windows with win32 threads.
Here are results of multi-threaded pgbench runs on Fedora 11 with intel
core i7 (8 logical cores = 4 physical cores * HT). -j8 (8 threads) was
the best and the tps is 4.5 times of -j1, that is a traditional result.
$ pgbench -i -s10
$ pgbench -n -S -c64 -j1 => tps = 11600.158593
$ pgbench -n -S -c64 -j2 => tps = 17947.100954
$ pgbench -n -S -c64 -j4 => tps = 26571.124001
$ pgbench -n -S -c64 -j8 => tps = 52725.470403
$ pgbench -n -S -c64 -j16 => tps = 38976.675319
$ pgbench -n -S -c64 -j32 => tps = 28998.499601
$ pgbench -n -S -c64 -j64 => tps = 26701.877815
Is it acceptable to use pthread in contrib module?
If ok, I will add the patch to the next commitfest.
pgbench_history, and pgbench_tellers, rather than just accounts, branches,
history, and tellers. This is to prevent accidental conflicts with real
application tables, as has been reported to happen at least once. Also
remove the automatic "SET search_path = public" that it did at startup,
as this seems to restrict testing flexibility without actually buying much.
Per proposal by Joshua Drake and ensuing discussion.
Joshua Drake and Tom Lane
1. -i option should run vacuum analyze only on pgbench tables, not *all*
tables in database.
2. pre-run cleanup step was DELETE FROM HISTORY then VACUUM HISTORY.
This is just a slow version of TRUNCATE HISTORY.
Simon Riggs
hazards. Instead teach these programs to prompt for a password when
necessary, just like all our other programs.
I did not bother to invent -W switches for them, since the return on
investment seems so low.
couldn't possibly HAVE_GETOPT. I believe this is the most appropriate
form of the patch submitted 2007-08-07 by Hiroshi Saito, though not
having a Windows build environment I won't know for sure till I see
the buildfarm results.
Smith. Along with Japanese doc updation by Tasuo Ishii.
> This patch changes the way pgbench outputs its latency log files so that
> every transaction gets a timestamp and notes which transaction type was
> executed. It's a one-line change that just dumps some additional
> information that was already sitting in that area of code. I also made a
> couple of documentation corrections and clarifications on some of the more
> confusing features of pgbench.
>
> It's straightforward to parse log files in this format to analyze what
> happened during the test at a higher level than was possible with the
> original format. You can find some rough sample code to convert this
> latency format into CVS files and then into graphs at
> http://www.westnet.com/~gsmith/content/postgresql/pgbench.htm which I'll
> be expanding on once I get all my little patches sent in here.
Also tweak README.pgbench/README.pgbench_jis:
Remove history after pgbench was added to PostgreSQL contrib module.
Those info was not only redundant since it has already been in CVS
log, but also incomplete.
--------------------------------------------------------------------------
The attached is a patch to optimize contrib/pgbench using new 8.3 features.
- Use DROP IF EXISTS to suppress errors for initial loadings.
- Use a combination of TRUNCATE and COPY to reduce WAL on creating
the accounts table.
Also, there are some cosmetic changes.
- Change the output of -v option from "starting full vacuum..."
to "starting vacuum accounts..." in reflection of the fact.
- Shape duplicated error checks into executeStatement().
There is a big performance win in "COPY with no WAL" feature.
Thanks for the efforts!
--------------------------------------------------------------------------
pgbench calls random() later, so it should have called srandom().
On most platforms except Windows srandom() is actually identical
to srand(), so the bug only bites Windows users.
per bug report from Akio Ishida.
scenarios. With multiple clinets, only the first client got the right
scaling factor and this gave a illusion of better performance in case
of the scaling factor greater than 1.
max_stack_depth is not set to an unsafe value.
This commit also provides configure-time checking for <sys/resource.h>,
and cleans up some perhaps-unportable code associated with use of that
include file and getrlimit().
- predefined variable "tps"
The value of variable tps is taken from the scaling factor
specified by -s option.
- -D option
Variable values can be defined by -D option.
- \set command now allows arithmetic calculations.
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
Remove unportable use of tfind/tsearch in favor of bsearch. Fix up
random number generator to use random() not rand() and to actually honor
its min/max arguments properly. That wasn't so important before, but
with exposure of capability to ask for general ranges, it will be.
warnings:
- remove pointless "extern" keyword from some function definitions in
contrib/tsearch2
- use "NULL" not "0" as NULL pointer in contrib/tsearch,
contrib/tsearch2, contrib/pgbench, and contrib/vacuumlo
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON. Still TODO: provide some client-side autocommit
logic in libpq.
Create objects in public schema.
Make spacing/capitalization consistent.
Remove transaction block use for object creation.
Remove unneeded function GRANTs.
false. per Tom Lane's suggestion. See:
Subject: Suggested change to pgbench
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tatsuo Ishii <t-ishii@sra.co.jp>
Cc: pgsql-patches@postgreSQL.org
Date: Sun, 06 Oct 2002 12:37:27 -0400
for more details.
snprintf() in contrib/. I didn't touch the places where pointer
arithmatic was being used, or other areas where the fix wasn't
trivial. I would think that few, if any, of the usages of sprintf()
were actually exploitable, but it's probably better to be paranoid...
Neil Conway
> Hi Tatsuo,
>
> I've attached a patch for the version of pgbench in CVS. It includes the
> following changes:
>
> - fix some spelling mistakes, indentation stuff, etc.
>
> - minor code cleanup -- (void) args instead of (), etc.
>
> - allocate the state array dynamically, so that it is only as
> large as needed. This reduces the memory consumption of pgbench
> slightly, and makes a larger MAXCLIENTS setting possible
>
> - (the only controversial change) add an option "-l" to log
> transaction latencies to a file. The "transaction latency"
> is the time between when the BEGIN is issued and the transaction
> commits. This is written to a file, along with the client #
> and the transaction #. The data in the file can then be used
> for things like:
>
> - consistency analysis: is the TPS the same through the
> entire run of pgbench, or does it change?
>
> - more detailed stats: what is the average latency, worse-case
> latency, best-case latency?
>
> - graphs: feed the data to gnuplot, graph latency versus. time
>
> - etc.
>
> I was going to store this data in memory and write it to disk
> at the end of the pgbench run, but that isn't feasible because
> the data can be very large: for example, ~70MB if benchmarking
> 128 clients doing 100,000 transactions each.
>
> Cheers,
>
> Neil
are now separate files "postgres.h" and "postgres_fe.h", which are meant
to be the primary include files for backend .c files and frontend .c files
respectively. By default, only include files meant for frontend use are
installed into the installation include directory. There is a new make
target 'make install-all-headers' that adds the whole content of the
src/include tree to the installed fileset, for use by people who want to
develop server-side code without keeping the complete source tree on hand.
Cleaned up a whole lot of crufty and inconsistent header inclusions.
* the result is not recorded anywhere
* the result is not used anywhere
* the result is only used in some places, whereas others have been getting away with it
* the result is used improperly
Also make command line options handling a little better (e.g., --disable-locale,
while redundant, should really still *dis*able).
