From 8099a579c80b6190ee3bb0dc7edbd318c6a041a4 Mon Sep 17 00:00:00 2001 From: "Paul Buetow (pluto.buetow.org)" Date: Sat, 28 Sep 2013 17:33:55 +0200 Subject: fix --- sload.buetow.org/content/home.xml | 100 +++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 50 deletions(-) diff --git a/sload.buetow.org/content/home.xml b/sload.buetow.org/content/home.xml index 24c99ae..705ae0a 100644 --- a/sload.buetow.org/content/home.xml +++ b/sload.buetow.org/content/home.xml @@ -1,54 +1,54 @@ - SLoad - Calculating server CPU loads - - - In order to learn functional programming and to calculate server loads at work I programmed in my spare time this small tool using the purely functional programming language - Haskell! - SLoad is an abbreviation for serverload. SLoad uses basic parameters (current CPU peak, current requests per second) for approximating the need of additional servers. - - In order to get started check it out from the Subversion repository. You also need to install GHC (the Haskell compiler). - -pbuetow@earth:~/svn/sload/trunk$ make -ghc SLoad.hs -o sload - - Lets imagine you own an apache server cluster which consists of 12 physical servers. The current maximum CPU usage (CPU peak) is 70%. A single server of the cluster handles at the moment 323 requests per seconds (request peak). And you want to know "does my farm handle 5000000 more requests per day?": - -pbuetow@earth:~/svn/sload/trunk$ ./sload --name=serverfarm.example.net --servers=12 \ - --cpuPeak=70 --peak=323 --requests=5000000 -Requests : 5000000.0 -Percentage of req. to use: 100.0 -Approximated peak: 277.77777 requests per second (Peak = 2 * (5000000.0/(60 * 60 * 10))) -serverfarm.example.net (12.0 Servers): - currentPeakPerServer: 323.0 - currentCpuPeakPerServer: 70.0 - currentPeakPerFarm: 3876.0 - possiblePeakPerFarm: 5038.8 - possibleAddPeak (possiblePeakPerFarm - currentPeakPerFarm): 1162.7998 - addPeakPerServer: 23.148148 - addPeakPerFarm: 277.77777 - leftPeak (possibleAddPeak - addPeakPerFarm): 885.02203 - currentCpuPerPeak (currentCpuPeakPerServer / currentPeakPerServer): 0.21671827 - neededCpuPeakPerServer (currentCpuPeakPerServer + addPeakPerServer * currentCpuPerPeak): \ - 75.016624 - - The approximated peak is being calculated using 2 * (requestsPerDay/10h). This formular has been well-tried and tested. It is not proven that this formular is always right, but it is more a 'worst case' approach. Which is ok for calculating server loads as long as you don't do a 'best case' calculation which may lead to a server overload. The value of neededCpuPeakPerServer shows if the cluster will handle the additional amount of requests. If neededCpuPeakPerSerer is less than 85 it should be ok. A value between 85 and 100 may be critical. A value more than 100 shows that there is definitive not enough power behind your cluster. - - - Requests: Requests per day your server should handle additionally to the current server load. You want to find out if your server cluster will handle this. - Percentage of req. to use: If you use 50, only half of "Requests" will be used in the following calculations.. - currentPeakPerServer: Requests per seconds a single server of the cluster handles (peak) - currentCpuPeakPerServer: The maximum (peak) CPU load of one of your servers. - currentPeakPerFarm: currentPeakPerServer * number of servers in the cluster. - possiblePeakPerFarm: How many requests per seconds your farm may handle (depending on the CPU % which is left) - possibleAddPeak: How many requests per seconds your farm may handle additionally to the CPU usage (depending on the CPU % which is left) - addPeakPerServer: How many requests per seconds a single server of your cluster may handle additionally. - addPeakPerFarm: addPeakPerServer * number of servers in the cluster. - leftPeak: How many requests per second can be handled more even after adding "Requests" to the cluster. - currentCpuPerPeak: How many CPU % is needed for a single request. - neededCpuPeakPerServer: How many CPU % (peak) is needed for a single server of the cluster after adding "Requests". - - + SLoad + Calculating server CPU loads + + + In order to learn functional programming and to calculate server loads at work I programmed in my spare time this small tool using the purely functional programming language + Haskell! + SLoad is an abbreviation for serverload. SLoad uses basic parameters (current CPU peak, current requests per second) for approximating the need of additional servers. + + In order to get started check it out from the Subversion repository. You also need to install GHC (the Haskell compiler). + + pbuetow@earth:~/svn/sload/trunk$ make + ghc SLoad.hs -o sload + + Lets imagine you own an apache server cluster which consists of 12 physical servers. The current maximum CPU usage (CPU peak) is 70%. A single server of the cluster handles at the moment 323 requests per seconds (request peak). And you want to know "does my farm handle 5000000 more requests per day?": + + pbuetow@earth:~/svn/sload/trunk$ ./sload --name=serverfarm.example.net --servers=12 \ + --cpuPeak=70 --peak=323 --requests=5000000 + Requests : 5000000.0 + Percentage of req. to use: 100.0 + Approximated peak: 277.77777 requests per second (Peak = 2 * (5000000.0/(60 * 60 * 10))) + serverfarm.example.net (12.0 Servers): + currentPeakPerServer: 323.0 + currentCpuPeakPerServer: 70.0 + currentPeakPerFarm: 3876.0 + possiblePeakPerFarm: 5038.8 + possibleAddPeak (possiblePeakPerFarm - currentPeakPerFarm): 1162.7998 + addPeakPerServer: 23.148148 + addPeakPerFarm: 277.77777 + leftPeak (possibleAddPeak - addPeakPerFarm): 885.02203 + currentCpuPerPeak (currentCpuPeakPerServer / currentPeakPerServer): 0.21671827 + neededCpuPeakPerServer (currentCpuPeakPerServer + addPeakPerServer * currentCpuPerPeak): \ + 75.016624 + + The approximated peak is being calculated using 2 * (requestsPerDay/10h). This formular has been well-tried and tested. It is not proven that this formular is always right, but it is more a 'worst case' approach. Which is ok for calculating server loads as long as you don't do a 'best case' calculation which may lead to a server overload. The value of neededCpuPeakPerServer shows if the cluster will handle the additional amount of requests. If neededCpuPeakPerSerer is less than 85 it should be ok. A value between 85 and 100 may be critical. A value more than 100 shows that there is definitive not enough power behind your cluster. + + + Requests: Requests per day your server should handle additionally to the current server load. You want to find out if your server cluster will handle this. + Percentage of req. to use: If you use 50, only half of "Requests" will be used in the following calculations.. + currentPeakPerServer: Requests per seconds a single server of the cluster handles (peak) + currentCpuPeakPerServer: The maximum (peak) CPU load of one of your servers. + currentPeakPerFarm: currentPeakPerServer * number of servers in the cluster. + possiblePeakPerFarm: How many requests per seconds your farm may handle (depending on the CPU % which is left) + possibleAddPeak: How many requests per seconds your farm may handle additionally to the CPU usage (depending on the CPU % which is left) + addPeakPerServer: How many requests per seconds a single server of your cluster may handle additionally. + addPeakPerFarm: addPeakPerServer * number of servers in the cluster. + leftPeak: How many requests per second can be handled more even after adding "Requests" to the cluster. + currentCpuPerPeak: How many CPU % is needed for a single request. + neededCpuPeakPerServer: How many CPU % (peak) is needed for a single server of the cluster after adding "Requests". + + -- cgit v1.2.3