P.S. to clarify, your application is running within that process, which is why a memory like makes it grow
On Thu, 29 Aug 2019 at 8:50 am, Nigel B. Peck <nigelbp...@gmail.com> wrote: > > It stops when you change to 1 because it kills the child process after > every single request! Try upgrading Apache to a recent version if you’re > concerned about that, but this is not likely at all to because of Apache. > Perhaps others with more experience have thoughts on this situation? > > On Thu, 29 Aug 2019 at 3:52 am, Arnav Garg <arnav.g...@india.nec.com> > wrote: > >> Hi Nigel Sir, >> >> >> >> Thanks for your continuous support and prompt reply. I had one more query >> as follows: >> >> >> >> >> I’m not suggesting it’s a memory leak in Apache, rather in the >> application(s) that you’re running on Apache. >> >> >> >> After my investigation and your suggestion, I had tuned my apache-server >> with MaxConnectionPerChild to a value “1” and things started to change. The >> memory consumption did not rise in comparison with other values. Also, I >> tried with MaxConnectionPerChild to “100”, but the results were same as >> MaxConnectionPerChild set to “0” i.e. high memory consumption within few >> seconds. So I couldn’t understand why memory leak is related to our >> application(CKAN) & not apache, as memory consumption changes with this >> parameter(i.e. MaxConnectionPerChild). >> >> >> >> So, if you can please suggest/clarify as to, why do you think my >> “application”- CKAN(an open data portal) is having a problem? I think >> memory leak is from Apache side. >> >> >> >> Thanks & regards, >> >> Arnav >> >> >> >> >> >> >> >> *From:* Arnav Garg [mailto:arnav.g...@india.nec.com] >> *Sent:* Wednesday, August 28, 2019 12:00 PM >> *To:* users@httpd.apache.org >> *Subject:* RE: [users@httpd] Apache process crashes, utilizing high >> memory >> >> >> >> Hi Nigel, >> >> >> >> Thanks for your prompt reply, I had one more doubt: >> >> >> >> While keeping the value of MaxConnectionPerChild to 1, my memory >> consumption do not increase as rapidly as it was earlier when it was set to >> 0. >> >> >> >> Here are the statistics: >> >> >> >> *My initial memory was : * >> >> *USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND* >> >> ckan-ap+ 12793 0.2 0.0 304068 6096 ? Sl 06:35 0:00 >> ckan_default -k start >> >> ckan-ap+ 12794 0.2 0.0 304068 6104 ? Sl 06:35 0:00 >> ckan_default -k start >> >> ckan-ap+ 12795 0.0 0.0 304076 6104 ? Sl 06:35 0:00 >> ckan_default -k start >> >> ckan-ap+ 12796 0.0 0.0 304068 6104 ? Sl 06:35 0:00 >> ckan_default -k start >> >> >> >> After firing 105 requests/per sec for 5 times with a Thread delay of 360 >> milliseconds using Jmeter. >> >> >> >> *The memory after firing the requests* >> >> >> >> *Case 1: **When I used to have MaxConnectionPerChild “0”:* >> >> >> >> The output observed using *“top”* command: >> >> >> >> *USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND* >> >> ckan-ap+ 12793 14.4 1.5 1444920 124880 ? Sl 06:35 0:13 >> ckan_default -k start >> >> ckan-ap+ 12794 14.0 1.4 1441080 119300 ? Sl 06:35 0:13 >> ckan_default -k start >> >> ckan-ap+ 12795 14.8 1.5 1442120 120724 ? Sl 06:35 0:14 >> ckan_default -k start >> >> ckan-ap+ 12796 14.5 1.5 1442616 120904 ? Sl 06:35 0:13 >> ckan_default -k start >> >> >> >> *Case 2: **When MaxConnection PerChild was set to “1”.* >> >> >> >> *USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND* >> >> ckan-ap+ 13448 13.6 1.3 *845368* 108904 ? Sl 06:39 0:11 >> ckan_default -k start >> >> ckan-ap+ 13449 11.6 1.3 *845376* 104560 ? Sl 06:39 0:09 >> ckan_default -k start >> >> ckan-ap+ 13450 11.7 1.2 *844608* 102696 ? Sl 06:39 0:09 >> ckan_default -k start >> >> ckan-ap+ 13451 11.8 1.2 *844344* 102392 ? Sl 06:39 0:09 >> ckan_default -k start >> >> >> >> The value highlighted in yellow remains almost the same or nearby when >> the performance testing was done for 2 hours. >> >> >> >> *Case 3: **When MaxConnectionPerChild was set to “100”.* >> >> Output: same as Case 1. >> >> >> >> *Doubt:* >> >> if you can please let us know on the performance or any side effects if I >> keep the value of MaxConnectionPerChild as 0 , 1 and 100? >> >> >> >> Thanks & Regards >> >> Arnav >> >> >> >> >> I’m suggesting 100 because it seems you have a memory leak, so looking >> to make sure they are restarted before that takes up too much memory. The >> cost is the overhead of spawning a new process every X number of >> connections. >> >> >> >> >> If you set it higher then your memory leak will have more effect. >> >> >> >> Will there be any performance impact >> >> >> >> >> >> *From:* Nigel B. Peck [mailto:nigelbp...@gmail.com <nigelbp...@gmail.com>] >> >> *Sent:* Thursday, August 22, 2019 11:10 AM >> *To:* users@httpd.apache.org >> *Subject:* Re: [users@httpd] Apache process crashes, utilizing high >> memory >> >> >> >> On Thu, 22 Aug 2019 at 12:02 am, Arnav Garg <arnav.g...@india.nec.com> >> wrote: >> >> Hi Nigel, >> >> >> >> Thanks for your prompt reply. >> >> Can you please help me in clarifying some of my doubts? >> >> 1. What is the significance of setting MaxConnectionsPerChild to a >> value between 1-100 ? >> >> 2. What are the possible reasons for not setting >> MaxConnectionsPerChild to a high value, greater than 100 ? >> >> It specifies the number of connections that a child process will serve >> before being closed and a new one spawned. Having it as 0 means there’s no >> limit so they just keep running. >> >> >> >> I’m suggesting 100 because it seems you have a memory leak, so looking to >> make sure they are restarted before that takes up too much memory. The cost >> is the overhead of spawning a new process every X number of connections. >> >> >> >> If you set it higher then your memory leak will have more effect. >> >> >> >> Best thing is to set it and then monitor and load test the server to get >> data to guide decisions on what works for your situation. And identify and >> fix the memory leak :) >> >> >> >> Hope that helps. >> >> >> >> Nigel >> >> >> >> Web Technologies and Linux Admin Mentor >> >> https://codementor.io/nigelbpeck >> >> >> >> >> >> >> ------------------------------ >> >> The contents of this e-mail and any attachment(s) are confidential and >> intended for the named recipient(s) only. It shall not attach any liability >> on the originator or NECTI or its affiliates. Any views or opinions >> presented in this email are solely those of the author and may not >> necessarily reflect the opinions of NECTI or its affiliates. Any form of >> reproduction, dissemination, copying, disclosure, modification, >> distribution and / or publication of this message without the prior written >> consent of the author of this e-mail is strictly prohibited. If you have >> received this email in error please delete it and notify the sender >> immediately. >> ------------------------------ >> The contents of this e-mail and any attachment(s) are confidential and >> intended for the named recipient(s) only. It shall not attach any liability >> on the originator or NECTI or its affiliates. Any views or opinions >> presented in this email are solely those of the author and may not >> necessarily reflect the opinions of NECTI or its affiliates. Any form of >> reproduction, dissemination, copying, disclosure, modification, >> distribution and / or publication of this message without the prior written >> consent of the author of this e-mail is strictly prohibited. If you have >> received this email in error please delete it and notify the sender >> immediately. >> >
