Response Time Analysis of Web Templates

Transcription

1 Response Time Analysis of Web Templates Prerequisites To generate trace files that are required for the detailed performance analysis you need to download and unpack the file IEMon.zip. This file can be found at Performance. Frontend Response Time Analysis For the frontend response time analysis the IEMon.exe tool is used. This tool is a simplified Web browser with enhanced HTTP protocol logging facilities. While executing an HTTP request the tool logs all outgoing and incoming protocol messages and other browser events, together with a millisecond based time stamp, into a log file. From this log it is possible to extract the time between sending an HTTP request and receiving the HTML response, and the time required by the browser to render this HTML response. Both times together are perceived as response time by the end user. Backend Response Time Analysis For the backend response time analysis we rely on the contents of ABAP runtime traces. In the context of Web reporting, the ABAP trace needs to be activated whenever a HTTP request arrives at the corresponding service handler. This is done within transaction SICF (see detailed description below). As ABAP tracing always has significant impact on the response time, we recommend creating the frontend log file and the ABAP trace files in separate executions of the query. Generation of Trace files Installation of IEMon.exe In order to use the IEMon.exe analysis tool, unpack the archive IEMon.exe into a separate directory. IEMon.exe can be executed without any further installation steps. Usage of IEMon.exe IEMon.exe is a simple Web browser with enhanced protocol logging facilities. You can enter any URL in the address bar and press the Navigate button to load and display the Web page. IEMon creates a log file iemon.txt in the TEMP directory %TEMP which contains information about various browser events. To display the progress of the protocol logging, activate the check box Display Progress. With the Open Log File button you can conveniently load the log file into notepad.

2 Contents of Log File The log file contains information about various browser events. Below is an extract of a sample log file: 11:57: x Before Navigate: :57: > Download Begin 11:57: <- Download Complete 11:57: > Download Begin 11:57: Status Text Change: Opening page bi at 11:57: Progress Change READYSTATE_LOADING :57: Progress Change READYSTATE_LOADING :57: Progress Change READYSTATE_LOADING :57: Status Text Change: 11:57: Title: SAP 11:57: * Navigate Complete: 11:57: Title: SAP - mysap Business Intelligence Home 11:57: Status Text Change: Opening page bi at 11:57: Progress Change READYSTATE_INTERACTIVE :57: Progress Change READYSTATE_INTERACTIVE :57: Status Text Change: Done 11:57: Progress Change READYSTATE_INTERACTIVE :57: Progress Change READYSTATE_INTERACTIVE :57: <- Download Complete 11:57: Progress Change READYSTATE_COMPLETE :57: # Document complete: 11:57: Web document is finished downloading For our response time analysis we need to look at only three types of events: Before Navigate: The HTTP request is being sent to the Web server. Navigate Complete: The Web server responds with an HTML stream. Document Complete: The browser has finished rendering the Web page. In our example above, the HTTP request was sent at 11:57: and the response arrived at 11:57: This is equivalent to a load time of 581 ms. Between 11:57: and 11:57: the browser was rendering the HTML code, so the rendering time was 951 ms. The total query response time sums up to ms.

3 If IEMon.exe is used to trace Web pages in a portal environment, multiple URLs are called and logged in the trace file. For these cases, the three events carry the corresponding URL, so the proper log file entries have to be matched according to those URLs. Important note: we recommend deleting the contents of the log file before starting a new analysis. This also applies for queries with multiple navigation steps. You should start a new trace before immediately before each navigation step. To get rid of old trace information, open the log file of IEMon by pressing the Open Log File button, mark all its contents, delete it, and save the file to it s original location (Temp directory). After the query has executed, open the log file again, and store it into a trace file directory. You can find further information on IEMon.zip. in the file ReadMe.html which is included in the archive. Analysis of Log File In order to make the output of IEMon more readable, you can use the program analyze_iemon.exe to format the IEMon log file. This program scans the IEMon log file and extracts those records which identify the load and rendering times. The output produced by analyze_iemon.exe can be written into a.csv (comma separated values) file and conveniently be opened with Microsoft Excel. Given the above example, you could call analyze_iemon.exe with the path to the IEMon log file as command line parameter, redirecting the output to a.csv file: analyze_iemon.exe iemon.txt > example.csv The contents of the.csv file can be displayed in Excel: Start time rel. start Load time Render time Total time URL 11:57: http:// The column rel. start describes the relative start time in ms from the first URL in the list (if several URLs are called). Load time and Render time denote times as described above. The column Total time contains the total response time of an URL as perceived by the end user. Activation of the ABAP trace for Web services While IEMon.exe only logs information about the frontend response time, our Web query analysis also looks into the details of the query execution within the Web Application Server. Detailed information is obtained from an ABAP trace which needs to be activated when the HTTP request is being processed by WAS. You need to activate the ABAP tracing in transaction SICF on node /sap/bw. Expand the default_host tree and mark the bw entry as shown in the screen shot below. Then select Edit Runtime Analysis Activate. Note: On systems with multiple application servers make sure to activate the trace on the server that will handle the HTTP request. Make sure that you activate the check box Only calls from SAPGUI-IP. With this check box enabled, only those requests coming from the TCP/IP connection which hosts the SAPGUI will cause a trace file to be created. If you do not check this box, the system traces all other incoming HTTP requests as well, which may have a negative impact on the overall system performance. Incoming http requests will only be traced after a new connection has

4 been established. If you have an open Web browser (or IEMon) please shut the browser down and restart it before you start tracing the ABAP calls. An incoming HTTP request causes a trace file to be generated. This trace file can be analyzed with transaction SE30. If multiple HTTP requests are processed (e.g. a selection screen, or multiple Web queries from a Web template) each request generates an individual trace file. Note: On systems with multiple application servers make sure to call transaction SE30 on the server that has handled the HTTP request and produced the trace file. Open transaction SE30, select Other file, specify the user SAPSYS and choose the proper trace file from the list. To find all relevant trace files, we recommend deleting all previous trace files before executing the Web query analysis. Double click the trace file to get an overview screen, then press the Hit List button (F5) to see the detailed trace information. Download this trace information into a local file onto your PC (System List Save Local File) as unconverted file.

5 List of files required for Detailed Web Query Analysis The trace files of IEMon and the ABAP traces can be further analyzed by SAP. For a detailed Web query analysis the following files are required: Iemon.txt: output of IEMon.exe (remember to delete the contents of the file before navigating to the Web page) trace1.txt, tracen.txt: Downloaded ABAP trace files (one for each query processed by WAS) If requested by SAP, please provide all trace files described above, using separate directories for different query executions.