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> 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
188 lines
4.9 KiB
Plaintext
188 lines
4.9 KiB
Plaintext
pgbench README 2002/07/20 Tatsuo Ishii (t-ishii@sra.co.jp)
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o What is pgbench?
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pgbench is a simple program to run a benchmark test sort of
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"TPC-B". pgbench is a client application of PostgreSQL and runs
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with PostgreSQL only. It performs lots of small and simple
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transactions including select/update/insert operations then
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calculates number of transactions successfully completed within a
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second (transactions per second, tps). Targeting data includes a
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table with at least 100k tuples.
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Example outputs from pgbench look like:
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number of clients: 4
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number of transactions per client: 100
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number of processed transactions: 400/400
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tps = 19.875015(including connections establishing)
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tps = 20.098827(excluding connections establishing)
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Similar program called "JDBCBench" already exists, but it requires
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Java that may not be available on every platform. Moreover some
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people concerned about the overhead of Java that might lead
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inaccurate results. So I decided to write in pure C, and named
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it "pgbench."
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o features of pgbench
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- pgbench is written in C using libpq only. So it is very portable
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and easy to install.
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- pgbench can simulate concurrent connections using asynchronous
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capability of libpq. No threading is required.
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o How to install pgbench
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(1) Configure and build the standard Postgres distribution.
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You can get away with just running configure at the top level
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and doing "make all" in src/interfaces/libpq.
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(2) Run make in this directory.
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You will see an executable file "pgbench". You can run it here,
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or install it with the standard Postgres programs by doing
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"make install".
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o How to use pgbench?
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(1) Initialize database by:
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pgbench -i <dbname>
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where <dbname> is the name of database. pgbench uses four tables
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accounts, branches, history and tellers. These tables will be
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destroyed. Be very careful if you have tables having same
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names. Default test data contains:
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table # of tuples
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-------------------------
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branches 1
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tellers 10
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accounts 100000
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history 0
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You can increase the number of tuples by using -s option. See
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below.
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(2) Run the benchmark test
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pgbench <dbname>
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The default configuration is:
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number of clients: 1
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number of transactions per client: 10
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o options
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pgbench has number of options.
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-h hostname
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hostname where the backend is running. If this option
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is omitted, pgbench will connect to the localhost via
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Unix domain socket.
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-p port
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the port number that the backend is accepting. default is
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libpq's default, usually 5432.
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-c number_of_clients
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Number of clients simulated. default is 1.
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-t number_of_transactions
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Number of transactions each client runs. default is 10.
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-s scaling_factor
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this should be used with -i (initialize) option.
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number of tuples generated will be multiple of the
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scaling factor. For example, -s 100 will imply 10M
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(10,000,000) tuples in the accounts table.
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default is 1.
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-U login
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Specify db user's login name if it is different from
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the Unix login name.
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-P password
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Specify the db password. CAUTION: using this option
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might be a security hole since ps command will
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show the password. Use this for TESTING PURPOSE ONLY.
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-n
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No vacuuming and cleaning the history table prior to the
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test is performed.
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-v
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Do vacuuming before testing. This will take some time.
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With neither -n nor -v, pgbench will vacuum tellers and
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branches tables only.
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-S
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Perform select only transactions instead of TPC-B.
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-C
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Establish connection for each transaction, rather than
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doing it just once at beginning of pgbench in the normal
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mode. This is useful to measure the connection overhead.
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-l
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Write the time taken by each transaction to a logfile,
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with the name "pgbench_log.xxx", where xxx is the PID
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of the pgbench process. The format of the log is:
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client_id transaction_no time
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where time is measured in microseconds.
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-d
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debug option.
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o What is the "transaction" actually performed in pgbench?
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(1) begin;
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(2) update accounts set abalance = abalance + :delta where aid = :aid;
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(3) select abalance from accounts where aid = :aid;
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(4) update tellers set tbalance = tbalance + :delta where tid = :tid;
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(5) update branches set bbalance = bbalance + :delta where bid = :bid;
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(6) insert into history(tid,bid,aid,delta) values(:tid,:bid,:aid,:delta);
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(7) end;
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o License?
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Basically it is same as BSD license. See pgbench.c for more details.
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o History
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2002/07/20
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* patch contributed by Neil Conway.
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* code/document clean up and add -l option.
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2002/02/24
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* do not CHECKPOINT anymore while initializing benchmark
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* database. Add -N option.
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2001/10/24
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* "time"->"mtime"
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2001/09/09
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* Add -U, -P, -C options
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2000/1/15 pgbench-1.2 contributed to PostgreSQL
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* Add -v option
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1999/09/29 pgbench-1.1 released
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* Apply cygwin patches contributed by Yutaka Tanida
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* More robust when backends die
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* Add -S option (select only)
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1999/09/04 pgbench-1.0 released
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