Re: [HACKERS] review: pgbench progress report improvements
2013/9/13 Fabien COELHO coe...@cri.ensmp.fr Hello, About patch eols: postgresql patch -p1 ../pgbench-measurements-v2.**patch patching file contrib/pgbench/pgbench.c patching file doc/src/sgml/pgbench.sgml it can depends on o.s. I did tests on Fedora 14. and for patching without warning I had to use dos2unix tool. Hmmm. I use a Linux Ubuntu laptop, so generating DOS end of lines is unlikely if it is not there at the beginning. Running dos2unix on the patch file locally does not seem to change anything. So I assume that the patch encoding was changed somewhere along the path you used to get it. It is possible - but, this is only minor issue Pavel -- Fabien.
Re: [HACKERS] review: pgbench progress report improvements
2013/9/12 Fabien COELHO coe...@cri.ensmp.fr Hello Pavel, Thanks for your review. * patched with minor warning * compilable cleanly * zero impact on PostgreSQL server functionality * it does what was in proposal ** change 5sec progress as default (instead no progress) ** finalise a rate limit support - fixes a latency calculation Just a point about the motivation: the rationale for having a continuous progress report is that benchmarking is subject to possibly long warmup times, and thus a test may have to run for hours so as to be significant. I find running a command for hours without any hint about what is going on quite annoying. * code is clean * documentation is included * there is no voices against this patch and this patch increases a pgbench usability/ I have only one question. When I tested this patch with throttling I got a very similar values of lag. Yep. That is just good! What is sense, or what is semantic of this value? The lag measures the stochastic processus health. Actually, it measures how far behind schedule the clients are when performing throttled transactions. If it was to increase, that would mean that something is amiss, possibly not enough client threads or other issues. If it is small, then all is well. It is not detailed documented. It is documented in the section about the --rate option, see http://www.postgresql.org/**docs/devel/static/pgbench.htmlhttp://www.postgresql.org/docs/devel/static/pgbench.html ok, I see it now. So this patch is ready for commit Regards Pavel Should be printed this value in this form on every row? We can print some warning when lag is higher than latency instead? Hmmm... what is important is when the lag changes values. Generally one would indeed expect that to be smaller than the latency, but that is not really possible when transaction are very fast, say under -S with read-only queries that hit the memory cache. Also the problem with printing warnings is that it changes the output format, but it seems to me more useful to print the value, so that it can be processed automatically and simply. Also, from a remote client perspective, say a web application, the overall latency is the lag plus the transaction latency: you first wait to get through the database (lag), and then you can perform your transaction (latency). Or we can use this value, but it should be better documented, please. Is the documentation pointed above enough? -- Fabien.
Re: [HACKERS] review: pgbench progress report improvements
Hello, About patch eols: postgresql patch -p1 ../pgbench-measurements-v2.patch patching file contrib/pgbench/pgbench.c patching file doc/src/sgml/pgbench.sgml it can depends on o.s. I did tests on Fedora 14. and for patching without warning I had to use dos2unix tool. Hmmm. I use a Linux Ubuntu laptop, so generating DOS end of lines is unlikely if it is not there at the beginning. Running dos2unix on the patch file locally does not seem to change anything. So I assume that the patch encoding was changed somewhere along the path you used to get it. -- Fabien. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] review: pgbench progress report improvements
Hello Pavel, Thanks for your review. * patched with minor warning * compilable cleanly * zero impact on PostgreSQL server functionality * it does what was in proposal ** change 5sec progress as default (instead no progress) ** finalise a rate limit support - fixes a latency calculation Just a point about the motivation: the rationale for having a continuous progress report is that benchmarking is subject to possibly long warmup times, and thus a test may have to run for hours so as to be significant. I find running a command for hours without any hint about what is going on quite annoying. * code is clean * documentation is included * there is no voices against this patch and this patch increases a pgbench usability/ I have only one question. When I tested this patch with throttling I got a very similar values of lag. Yep. That is just good! What is sense, or what is semantic of this value? The lag measures the stochastic processus health. Actually, it measures how far behind schedule the clients are when performing throttled transactions. If it was to increase, that would mean that something is amiss, possibly not enough client threads or other issues. If it is small, then all is well. It is not detailed documented. It is documented in the section about the --rate option, see http://www.postgresql.org/docs/devel/static/pgbench.html Should be printed this value in this form on every row? We can print some warning when lag is higher than latency instead? Hmmm... what is important is when the lag changes values. Generally one would indeed expect that to be smaller than the latency, but that is not really possible when transaction are very fast, say under -S with read-only queries that hit the memory cache. Also the problem with printing warnings is that it changes the output format, but it seems to me more useful to print the value, so that it can be processed automatically and simply. Also, from a remote client perspective, say a web application, the overall latency is the lag plus the transaction latency: you first wait to get through the database (lag), and then you can perform your transaction (latency). Or we can use this value, but it should be better documented, please. Is the documentation pointed above enough? -- Fabien. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] review: pgbench progress report improvements
* patched with minor warning some minor issue: patch warning make[1]: Leaving directory `/home/pavel/src/postgresql/config' [pavel@localhost postgresql]$ patch -p1 pgbench-measurements-v2.patch (Stripping trailing CRs from patch; use --binary to disable.) patching file contrib/pgbench/pgbench.c (Stripping trailing CRs from patch; use --binary to disable.) patching file doc/src/sgml/pgbench.sgml I cannot reproduce these warnings: postgresql git branch test postgresql git checkout test Switched to branch 'test' postgresql patch -p1 ../pgbench-measurements-v2.patch patching file contrib/pgbench/pgbench.c patching file doc/src/sgml/pgbench.sgml Some details: postgresql patch --version patch 2.6.1 [...] postgresql sha1sum ../pgbench-measurements-v2.patch f095557ceae1409d2339f9d29d332cefa96e2153 [...] -- Fabien. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] review: pgbench progress report improvements
Dne 12. 9. 2013 17:34 Fabien COELHO coe...@cri.ensmp.fr napsal(a): * patched with minor warning some minor issue: patch warning make[1]: Leaving directory `/home/pavel/src/postgresql/config' [pavel@localhost postgresql]$ patch -p1 pgbench-measurements-v2.patch (Stripping trailing CRs from patch; use --binary to disable.) patching file contrib/pgbench/pgbench.c (Stripping trailing CRs from patch; use --binary to disable.) patching file doc/src/sgml/pgbench.sgml I cannot reproduce these warnings: postgresql git branch test postgresql git checkout test Switched to branch 'test' postgresql patch -p1 ../pgbench-measurements-v2.patch patching file contrib/pgbench/pgbench.c patching file doc/src/sgml/pgbench.sgml it can depends on o.s. I did tests on Fedora 14. and for patching without warning I had to use dos2unix tool. Some details: postgresql patch --version patch 2.6.1 [...] postgresql sha1sum ../pgbench-measurements-v2.patch f095557ceae1409d2339f9d29d332cefa96e2153 [...] -- Fabien.
[HACKERS] review: pgbench progress report improvements
Hello * patched with minor warning * compilable cleanly * zero impact on PostgreSQL server functionality * it does what was in proposal ** change 5sec progress as default (instead no progress) ** finalise a rate limit support - fixes a latency calculation * code is clean * documentation is included * there is no voices against this patch and this patch increases a pgbench usability/ I have only one question. When I tested this patch with throttling I got a very similar values of lag. [pavel@localhost ~]$ /usr/local/pgsql/bin/pgbench -T100 -j4 -c32 postgres -R 60 starting vacuum...end. progress: 5.0 s, 61.3 tps, 15.796 +- 11.287 ms lat, 0.118 ms lag progress: 10.0 s, 60.8 tps, 16.527 +- 12.965 ms lat, 0.120 ms lag [pavel@localhost ~]$ /usr/local/pgsql/bin/pgbench -T100 -j4 -c32 postgres -R 80 starting vacuum...end. progress: 5.0 s, 78.8 tps, 17.009 +- 11.666 ms lat, 0.163 ms lag progress: 10.1 s, 74.3 tps, 33.510 +- 55.456 ms lat, 0.092 ms lag [pavel@localhost ~]$ /usr/local/pgsql/bin/pgbench -T100 -j4 -c32 postgres -R 40 starting vacuum...end. progress: 5.2 s, 39.4 tps, 13.580 +- 10.283 ms lat, 0.182 ms lag progress: 10.1 s, 49.3 tps, 13.192 +- 6.772 ms lat, 0.135 ms lag What is sense, or what is semantic of this value? It is not detailed documented. Should be printed this value in this form on every row? We can print some warning when lag is higher than latency instead? Or we can use this value, but it should be better documented, please. Regards Pavel Stehule some minor issue: patch warning make[1]: Leaving directory `/home/pavel/src/postgresql/config' [pavel@localhost postgresql]$ patch -p1 pgbench-measurements-v2.patch (Stripping trailing CRs from patch; use --binary to disable.) patching file contrib/pgbench/pgbench.c (Stripping trailing CRs from patch; use --binary to disable.) patching file doc/src/sgml/pgbench.sgml
