Re: Informix FAQ

Art, newratios.ksh reports on one of the instances: Metric Ratio Report For 2K Cache Bufwaits Ratio: 0.140000% Buffer Turnover Rate: 363.58/hr Reset Time: 2010-01-14 00:04:59 Time elapsed: 9 Std. 56 Min. 03 Sek. (Modified the script a bit, so you can see these values). We have only 2K Buffers. The BTR would imply an turnaround of the buffers all 10 seconds. onstat -p shows: IBM Informix Dynamic Server Version 11.50.FC5W4 -- On-Line -- Up 26 days 21:46:18 -- 6269952 Kbytes Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 179093619 338619630 20158565492 99.11 11559700 26071392 6594149951 99.82 You see, bufwrits are 6594149951 and pagewrits only 6594149951. The ratios pagwrits/bufwrits is 0.004 or 0.4 %. Is the following conclusion true: If the ratio pagwrits/bufwrits is (very) low, then the significance of BTR isn't (very) high. BTW: We have 2,100,000 Buffers and we hve not too strong complaints. TIA, Reinhard. -----Original Message----- From: informix-list-bounces@iiug.org [mailto:informix-list-bounces@iiug.org]On Behalf Of Art Kagel Sent: Thursday, January 14, 2010 3:12 AM To: fandelau Cc: informix-list@iiug.org Subject: Re: Informix FAQ Hi Ramon, OK, I'll take a look at the script again over the weekend and let you know what's what. Thanks for trying it out and for the feedback. Art Art S. Kagel Advanced DataTools ( www.advancedatatools.com <http://www.advancedatatools.com>; ) IIUG Board of Directors ( art@iiug.org <mailto:art@iiug.org> ) See you at the 2010 IIUG Informix Conference April 25-28, 2010 Overland Park (Kansas City), KS www.iiug.org/conf <http://www.iiug.org/conf>; Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Advanced DataTools, the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Wed, Jan 13, 2010 at 8:45 PM, fandelau < fandelau@gmail.com <mailto:fandelau@gmail.com> > wrote: On Jan 7, 7:43 am, Art Kagel < art.ka...@gmail.com <mailto:art.ka...@gmail.com> > wrote: > <SNIP> > However, it is still a VERY useful metric. I have determined by observation > of many servers that if the BTR is ~10 or under the server is likely happy > and users are not complaining about performance. If the BTR is in higher > double digits some users will be experiencing slow performance or > intermittent responsiveness problems. If BTR is in the upper double or > triple digits then your phone is likely ringing with complaints or soon will > be. <SNIP> Art, I just downloaded the newratios tool from the IIUG, and I'm a bit perplexed by the results. I'm running IDS 11.10.FC3 on SunOS 5.10, and I have dbspaces with 2k (rootdbs and physlogdbs) and 16k (all others) pages respectively. This is what I'm getting in my biggest and supposedly busiest instance... please notice the BTR and UBTR: ReadAhead Utilization: 99.990000% Bufwaits Ratio: 1.650000% Buffer Turnover Rate: 1147.76/hr Used Buffer Turnover Rate: 43.15/hr ... and my phone is not ringing off the hook... ;o) I tried to follow the logic of your stored procedure and I noticed that the first foreach gets data from the sysprofile, which needless to say doesn't differentiate buffer sizes. Then, there is a select statement to get buffers from the sysconfig, which gets me the 2k buffers ONLY, after which we get the up time from the sysshmvals tables. Then the values are calulated based off of those values. The very last foreach tries to get columns that are not present in the sysbufpool table... and I know that the values that it tries to retrieve are used in the BTR and UBTR calculations. Perhaps I downloaded an old copy of newratios, but I think that there must be something wrong with the stored proc for it to return a BTR of over 1000 per hour. Please let me know what am I doing wrong. Thanks! Ramon _______________________________________________ Informix-list mailing list Informix-list@iiug.org <mailto:Informix-list@iiug.org> http://www.iiug.org/mailman/listinfo/informix-list <http://www.iiug.org/mailman/listinfo/informix-list>;