Seagate Info. Objective. Contents. EPF File Generation for Page-on-Demand Viewing

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1 EPF File Generation for Page-on-Demand Viewing Objective Contents This white paper will explain the technical architecture of Seagate Info s page on demand viewing system, particularly describing the process of the page-on-demand cache file creation. It also includes sections pertaining to: A component architecture flow-chart diagram Performance considerations Frequently asked questions (FAQ), with answers Troubleshooting tips EPF cache directory clean up process List of questions that need to be asked with respect to any problems that may be encountered with Seagate Info utilizing page-on-demand technology This document applies to Seagate Info versions 6 and 7. INTRODUCTION...4 COMPONENT ARCHITECTURE FLOW-CHART DIAGRAM...4 OVERVIEW...7 What is Page on demand?...7 Selecting Page on demand as a report viewing option...7 Selecting the number of cache pages that will be generated when a report is run....7 Cache Options Settings...7 Scheduling with Page on Demand...8 Viewing with Page on Demand...9 Maintenance of Cache Files...9 What are the effects that the cache directory size and cache page limits have on the run time and viewer performances?...10 FREQUENTLY ASKED QUESTIONS (FAQ)...10 What is the benefit of Page on demand?...10 What are EPF files?...11 When are EPF files generated?...11 If the EPF files are generated at view-time, how does the Info Desktop setting Maximum cache pages apply? /8/2002 3:52 PM Copyright 2001 Crystal Decisions, Inc. All Rights Reserved. Page 1

2 EPF File Generation for Page-on-Demand Viewing If the EPF File is already created at run-time, does it have to be recreated at view-time? If so, why?...12 When are the EPF files deleted?...12 What happens when instances are deleted from the Info Desktop?...13 What should the size of the cache directory be?...13 What is the difference between the SI Info APS and a post SI Info APS?...13 Why are no cache pages ever created if the Cache Limits is set to "0"? Is this by design?...13 What happens in the case of Drill Down?...13 Are drill-down.epf files created during report processing or during report viewing?...14 In the cache directory, what does each file extension represent?...14 In the Info Configuration Manager, under the Info Servers tab, there are two configuration options for the Info Agent; they are: Maximum Number of Threads In the Info Agent and Maximum Job Load. How are these settings to be used?...14 What is a Thread?...15 What is Multithreaded?...16 What is thread-safe?...16 When Maximum Number of Threads in the Info Agent is set to "1" in the Info Configuration Manager, six threads appear in the Performance Monitor. Why is this?...16 How does the Info Agent open a separate thread for each request?...16 How will the Info APS manage this many threads accordingly and are there any limitations?...16 What is the role of the Info APS in the page on demand process during.epf generation?...17 Why does it take so long for the report to process at scheduling time (it is so quick to process in the Report Designer)?...17 The suggested setting for Max Number of threads for the Info Agent in SI 6 is less than 10. What types of errors will be received if this threshold is exceeded?...18 If the Info Agent is busy with another request, where is the request queued?18 Is there a message indicated on the Info Viewer if the Info Agent is busy?...18 Is there a way to send a message to effectively cancel the cache processing request [from the viewer]?...18 When does the Info Agent close a report? Does it close the report when it sends the File back to the Viewer?...18 Since the Info Agent is based on one thread per report, is it true that the number of threads must equal the number of reports one wishes to run simultaneously?...19 If there are multiple computers that can be used for caching, and one Info Agent caches pages because of the Cache Page limit setting (or because Drill Down was performed on a report), the cached pages will be stored in memory on that computer. If the same page is requested by another user, it is served to the user in a timely manner but the files do not appear to be written anywhere. If the first Info Agent ceases to function, another Info Agent will process the requests but the cache files will have to be reprocessed. Why is that?...19 Why does the Info Agent need to hang on to the report?...19 Why does the Info Agent need to hang on to the drill-down report too?...19 Why is viewing an old instance slower than viewing a new instance? When an old instance is viewed again, why is viewing it then fast?...20 Does the regeneration process take a long time?...20 How can I make sure that is what s happening?...20 What can I do to make the report regenerate faster?...20 Is there a way to check that all of the cache files were created for a particular report instance?...20 How does the cache directory size setting work and what impact is there on both run time and viewer performance? /8/2002 3:52 PM Copyright 2001 Crystal Decisions, Inc. All Rights Reserved. Page 2

3 EPF File Generation for Page-on-Demand Viewing How does the Cache page limits per report object setting work and what impact is there on both run time and viewer performance?...21 What performance issues can be expected with varying report size, number of groups, record\group selections, formulas, and table joins?...21 What clean-up operation takes place with respect to the following: a) Deleting instances, b) stopping the Info Agent and Info APS, and c) resetting the Cache Directory size?...21 Does the Info Agent have to generate all pages, before it can display a specific page?...21 What effect do Row and Column security have on the viewing of report(s) created off of Info Views?...22 A user schedules a report for which the cache page limits are set to 20 pages and another user, of the same user group, views the report and goes to page 30. Are pages 1 to 20 recreated before pages 21 to 30 or does the Info APS see that 20 pages are there and it only needs to process 21 to 30?...22 If the next viewer is of the same user group and wants to see page 33, are only pages 31 to 33 created?...22 EPF CACHE DIRECTORY CLEAN UP PROCESS...23 Normal process:...23 'Daily Cleanup process'...23 STEPS TO COMPLETE BEFORE CALLING TECHNICAL SUPPORT:...24 Information to gather about your Seagate Info Environment...24 Information Regarding Temporary Files on a Computer and which component they are from:...25 APPENDIX A: TESTING RESULTS AND MISCELLANEOUS INFORMATION...26 Object Limits:...26 Temporary files:...26 Object Limit = 0:...27 Object Limit = 1:...27 CONTACTING CRYSTAL DECISIONS FOR TECHNICAL SUPPORT /8/2002 3:52 PM Copyright 2001 Crystal Decisions, Inc. All Rights Reserved. Page 3

4 EPF File Generation for Page-on-Demand Viewing Introduction The core components of Seagate Info (SI) Page on Demand technology are the: Info Agent (also known as the Info Viewing Server in Seagate Info architecture). This executable is called Ciagnt32.exe. Report Agent (also known as the Info Report Server in SI architecture). This executable is called Rptagent.exe. Info APS (also known as the Automated Process Scheduler in SI architecture). This executable is called Aps32.exe. Viewer (this can be the Info Viewer component on the Windows Info Desktop, or any of the web-based viewers from the WebAccess Desktops). Component Architecture Flow-Chart Diagram This flow-chart diagram shows all the components involved in Seagate Info s Page-on- Demand viewing system, with the aim of providing you with a better understanding of the Page-on-Demand cache file creation process. This diagram applies to Seagate Info versions 6.x and 7.x. Aside from visually showing the technical architecture of Page-on-Demand, this diagram also shows the flow process from component to component in Seagate Info. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, Inc. All Rights Reserved. Page 4

5 RptAgent Seagate Info Process report Generate EPF file up to max cache page limit Does the report have groups? No Viewer Yes Generate ETF file as well. Save EPF/ETF to cache directory Tell the APS the name of the EPF/ETF files Send request for the right pane Does the report have groups? Yes Send request for the left pane APS Receive request from viewer Yes Is the report s EPF file cached? Yes Does the selection formulas matches? Yes Are there cache files that match the viewer s group membership? Yes Read EPF file and send result to viewer. Successfully read the EPF/ETF file Yes Extract little cache file to disk Ask Sentinel to send the little EPF file, and delete it when done. No No No No Receive output files and EPF/ETF files Tell CIAgent to open the output file, and make ready to serve. Did RptAgent generate EPF/ETF files? Find an available Info Agent Yes Forward request to Info Agent Receive EPF\ETF cache from Info Agent Add EPF/ETF files to cache Read EPF file and send result to viewer. Add EPF/ETF files to cache Generate CRH files for EPF and ETF file. Create entry in cache table Delete old EPF files until the cache directory size is under limit. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 5 Info Agent Receive request from APS Open report Is report already open? No Open report No Yes Is it a drill down request? Is the base Yes report open? No Yes Load report Expand saved data Close oldest job Is the report busy with another request? Yes Yes Is the base report busy with another request? No Reuse the same print job Put the request on the queue Clone job Make copy of data Filter out non drilldown data How many pages 1 should we generate? Max page limit Generate EPF file for the page Generate EPF file up to max cache page limit Ask Sentinel to send the file back to the Viewer, and then delete the file. Send the result back to APS

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7 Overview What is Page on demand? Page on demand technology is a means of running and viewing a report on an On- Demand basis. Report pages will be generated and served to the viewer as they are needed, instead of having the entire report served to the viewer at the time of the initial viewing request. This option serves to optimize report-viewing time. Page on demand is governed by a few configuration settings within Seagate Info. These settings allow page on demand to be selected as a viewing option and also allow users to select the number of pages that are to be generated when the report is run. Because page on demand report generation writes files to the Cache directory, the Cache options settings can also impact page on demand report generation. Selecting Page on demand as a report viewing option From the Info Desktop under the Tools > Options menu, go to the Viewing Settings section and select Page on demand from server. The checkmark should appear in the selection box if the Page on demand option is desired. Selecting the number of cache pages that will be generated when a report is run. The number of cache pages to be generated when a given report object is scheduled can be set by highlighting the report object on the Info Desktop, right clicking, and then selecting Object Limits from the drop down menu. The Set Object Limits dialogue box will appear. The last setting in this box is Set Maximum Cache Pages. There are two possible choices. The first selection, Unlimited, allows all pages of the selected report object to be created as cache pages when the report is run. The second selection, Limited To xx Pages per Instance, allows the user to limit the number of cache pages to be generated; this setting can be set to 0 or it can be set to any number of pages. The setting Set Maximum Cache Pages can also be set by highlighting a report object and selecting the Info Desktop menu item View and then selecting Instance Limits. The Set Object Limits box will appear and cache page settings can be made as described above. Please note that this is an Object level setting and cannot be modified to govern specific instances. Cache Options Settings For Seagate Info 6 users, the Cache Options are found in the Info Administrator module under the Options tab. In version 6, the two settings of concern to those using page on demand are Report Cache > Cache Directory and Limit cache directory size to xx MB. For Seagate Info 7 users, the Cache Options are found in the Info Administrator module under the Instances tab, in the section called Report Caching. In version 7, there are 4 possible global Cache options that can be set to control page on demand, which are: Location (i.e. Cache directory location), Limit cache directory size to xx MB, Unlimited cache pages, and Limit cache pages to xx per instance. Report Cache > Cache Directory 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 7

8 This setting is where the Cache directory location is set. By default, Seagate Info 6 creates a directory of \\ComputerName\Cinfo\Cache. The default in Seagate Info 7 on a new installation is: \\ComputerName\Program Files \Seagate Software\SI\Cache. This is a default setting only and can be set to a directory of the user s choosing. When using the Page on demand option, report page files (explained below) will be written to this directory. Limit cache directory size to xx MB This option allows the user to select (by clicking on a box) to limit the cache directory size to a size of their choice. Leaving the box unchecked will allow the cache directory to grow in size as required in an unlimited manner. NOTE **Important**: If a cache directory size limit is selected, it must currently be set below gigabytes. A setting of 1.5 to 1.75 Gigabytes is recommended. If the cache directory size is not limited, the Gigabyte limit does not apply. Unlimited cache pages This is a new global setting introduced in Seagate Info 7 that controls the cache pages generated for all reports (both at scheduling time and view time). Previously, in version 6, this setting was only at the Report Object level on the Info Desktop. This setting allows all pages of the selected report object to be created as cache pages when the report is scheduled to run or viewed by a different user group member at view time. Limit cache pages to xx per instance This also is a new global setting introduced in Seagate Info 7 that controls the cache pages generated for all reports (both at scheduling time and view time). Previously, in version 6, this setting was only at the Report Object level on the Info Desktop. Scheduling with Page on Demand When a report is scheduled to run, the Report Agent or Info Report Server (Rptagent.exe) opens the report and checks to see if cache pages need to be generated for Page on demand (Info Desktop Module, View > Instance Limits > Set Maximum Cache Pages). If so, the report pages are generated by the Report Agent and stored along with paging and page index information in a group of files written to the Cache directory as defined in the Info Administrator module. A complete list of the associated file extensions and a brief description of their purpose is listed below. The actual file name, or prefix, will be unique for each scheduled instance..epf : Encapsulated Page Format (.EPF) is a concatenated version of the.epf files for each page. This file stores report pages ready for viewing..etf : stores the group tree information, basically, the left-pane of the Info Viewer..crh: stores information about the cache files. You should see one for the.etf files and another one for the.epf file. This file is generated by the Info APS after it has already added reference of the.epf and the.etf into its memory. [This file is also used by the Info APS to build the cached table on startup.] 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 8

9 .rdp: stores group paging information (stores which page each group is in)..rdx : stores where each page is located within the.epf file. The report pages are stored in a file with an.epf extension (the group tree is stored in the.etf file. The list of user group ids, that the scheduler belongs to, is stored with the cache.) When the cache files are completed, the Report Agent sends the information to the Info APS for storage. When the Info APS receives cache information, it will first check if the cache directory volume is at its maximum size. In version 7, this is located as follows: Info Administrator Module Instances tab > Report Caching > Limit cache directory size to xx MB. In version 6, this is located as follows: Info Administrator Module Options tab > Cache Options > Limit cache directory size to xx MB). If it is at its maximum size, it will clear old data from the cache (based on hit count and when the page was last hit). The Info APS will also store the cache file with the user group IDs. For optimization, after the job is finished, the Info APS will send the completed job to the Info Agent to open it for viewing. Viewing with Page on Demand If a report is viewed and then another user with the same SI user group ID hits the same page, the Info APS will send back the cached page. However, if the user belongs to a different SI user group, or they hit a different page, the Info APS will send the request to an Info Agent (see next paragraph). If the user belongs to the same SI user groups, but applies a selection formula, the Info APS will send the request to an Info Agent for processing. The Info Agent will open the report if not already opened. If the report is already opened, but the report is based on an Info View (.civ file), the Info Agent will "clone" the job (for optimization). The Info Agent will generate all the pages until it hits the page requested, and all the generated pages are then handed over to the Info APS to add to its cache table. The Info APS will then perform the same steps as described above under Scheduling with Page on Demand (under the last paragraph of the section). Maintenance of Cache Files The Info Agent also has a cache table that helps it to determine which reports it should keep in memory, thereby speeding up the time it takes to load a given report into memory. The cache for page on demand works independently of instances and objects on the Info Desktop. Deleting objects\instances on the Info Desktop (which will then delete the associated.rpt from its output directory) will NOT delete all of the associated cache files from the cache directory unless an available Info Agent is running. In SI version and later, when an Info Agent is running, the deletion of an instance from the Info Desktop will delete only those cache files created when the report was scheduled. Cache files created upon the viewing of additional pages will not be deleted. In version , the cached pages remaining in the cache directory would be cleaned up 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 9

10 when the cache directory had reached its maximum (Info Administrator Module, Options tab > Cache Options > Limit Cache Directory Size to xx MB) and cache space is required by new viewing requests. Closing the Info Agent will clear the Info Agent's cache table; however, it will not affect the Info APS cache table. Closing the Info APS will not clear the cache, because on startup, the Info APS will build the cache table based on the cache directory. "Resetting" the cache size might clear the cache, if a smaller setting has been selected. If it is necessary that the cache be cleared, the Cache directory contents should be deleted directly by accessing the Cache directory through the NT or Windows Explorer. NOTE The Info Viewer has no way of determining whether or not a requested page is cached; it simply requests the page from the Info APS and waits until the Info APS replies. The Info APS can determine which pages have been cached in memory. What are the effects that the cache directory size and cache page limits have on the run time and viewer performances? Larger cache directory size (as defined via the Info Administrator Module) means more pages can be cached. This translates to a faster report viewing time because Seagate Info has to generate.epf files less often. Larger cache page limits (as defined globally via the Info Administrator Module or over-ridden at the Report Object level) mean that the report takes longer to generate at schedule time but viewing time will be shorter. The longer wait for report generation, will only be experienced by the first user of a different SI user group. For subsequent viewers (assuming the cache size is sufficient), the pages should already be in the cache. NOTE If individual users do a lot of different selections or everyone belongs to different user groups, then setting a larger cache page limit will not help much with respect to report viewing speed; in this case, new pages will be generated and previously cached pages will not be used. Frequently Asked Questions (FAQ) What is the benefit of Page on demand? Page on demand was developed in order to facilitate a more efficient way of viewing reports. When the Info Viewer is being used and there is a request to view a page of a report, only that page is sent from the Info Agent to the user's (viewer s) computer. On the other hand, if the Info Analyzer is being used to view the report, Page on demand technology is NOT utilized. If a file share exists on the directory that contains the report (.RPT) instance and a report is opened from an Info Desktop using the Info Analyzer for viewing, the report is viewed by simply mapping back to the.rpt instance in the output directory. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 10

11 If this directory is not shared, the entire report is transferred by the Info APS to the desktop computer being used for viewing. This is accomplished by transferring the.rpt file from the Info Sentinel on the Info Server to the Info Sentinel on the client computer. For large reports, this could result in a long delay before viewing can begin. This makes Page on demand a desirable alternative. What are EPF files? EPF (Encapsulated Page Format) files are used for page on demand viewing with Seagate Info. Each file contains the image of pages of a report (the actual number of pages stored might vary depending on configuration settings selected). When are EPF files generated? EPF files can be created when a report is run at schedule time. EPF files can also be created when the report is viewed with the Info Viewer. NOTE If Maximum Cache Pages is unlimited and a report with many pages is being run, processing time will be affected and will therefore take a much longer time to process at scheduling time. The report viewing time will be shorter for the SI user group members that are in the same user group as the user who scheduled. In Seagate Info version 7, the configuration setting for Maximum Cache Pages file generation can be controlled globally for all reports via the Info Administrator tool or at the Report Object level (by right-clicking on the report object and choosing Properties > Limits). In Seagate Info version 6, there is no global control of all reports cache pages. The only configuration setting control is on a report-by-report basis on the Info Desktop. This setting can be found in the menu item View > Instance Limits > Set Maximum Cache Pages when a report object is highlighted; alternatively, on the Info Desktop, right-click on the report object and choose Object Limits > Set Maximum Cache Pages. The above configuration settings, if they are set to a setting > 0, will force.epf files to be generated when the report is run. If the Maximum Cache Pages are set at 0, then no.epf file is written to the Cache directory at runtime. An.EPF file for any page viewed is subsequently written to, and then immediately deleted from, the Cache directory. If Maximum Cache Pages has been set to a setting greater than 0, an.epf file containing the pages defined in the Cache Limits configuration setting is written to the Cache directory at runtime. When pages are viewed,.epf files for those pages requested are written to the cache directory. For example, if 'Maximum Cache pages' is set to "6", an.epf file encompassing all six pages will be written to the Cache directory at runtime. As this report is viewed,.epf files will be written to the Cache directory until six pages have been viewed. At this point, there will be 7.EPF files in the Cache directory; one large.epf file containing 6 pages of information and 6 smaller.epf files, one for each of the 6 pages viewed. As further pages are viewed, an.epf file for each page is written to, and then immediately deleted from, the cache directory. If Maximum Cache Pages is set to Unlimited, then 2.EPF files will be created at runtime: one for the entire report and one for the first page of the report. An.EPF file will be written to the Cache directory for each additional page viewed until all of the 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 11

12 report pages have been viewed. If the report is viewed and then the Info Viewer is closed and reopened for viewing, an additional.epf file will be written to the Cache directory when the Info Viewer is launched. This.EPF file represents the first page of the report. If at this point additional pages are viewed, an additional.epf file (one for each page viewed) will be written to the Cache directory. NOTE If Maximum Cache Pages is unlimited and a report with many pages is being run, processing time will be affected and will therefore take a much longer time to process at scheduling time. The report viewing time will be shorter for the SI user group members that are in the same user group as the user who scheduled. If the EPF files are generated at view-time, how does the Info Desktop setting Maximum cache pages apply? Example: Suppose a user runs a report where maximum cache pages is set to 10;.EPF files will be created for the first 10 pages of the report when the report is run. When the report is viewed with the Info Viewer, the user can see pages one through ten. When the user tries to view page eleven or greater, the Info Agent will create a new.epf file for the desired page and send it to the Info Viewer. If the EPF File is already created at run-time, does it have to be recreated at view-time? If so, why? For each EPF file, the Info APS stores information about requests that could reuse that EPF file, and the general rule is when a request comes in, the Info APS tries to find an EPF file that it can reuse. If the Info APS fails to find the.epf file, it will ask the Info Agent to recreate it. To be more specific: If the Info APS fails to read the EPF file, a new one will need to be generated. If the report is based on a CIV (Info View) and the user viewing the report is a member of a different user group(s) than the user who created the EPF files, the EPF files are created fresh and existing ones from previous viewing are not used. NOTE The existence of Info View row and column security does not affect the.epf algorithm. EPF files generated when a user drills down on a hidden section on a report are subject to the above behavior. These files CANNOT be generated during report processing. If the viewing request introduces a new selection formula, a new EPF file is created. When are the EPF files deleted? After the Info APS has retrieved the EPF files from the Info Agent, it tallies the total size of the cache directory. If the cache directory exceeds the maximum size (as was set in the Info Administrator), the least used EPF files are removed from the directory until the size is within the designated limit. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 12

13 What happens when instances are deleted from the Info Desktop? In SI versions and , deleting instances from the Info Desktop will only delete report output files (.RPT) and does NOT delete the associated cache files (i.e..epf) for that instance. (Unless an Info Agent is running, in which case the original cached files are deleted upon the deletion of a report instance.) What should the size of the cache directory be? If a limit has been set on cache pages via the Info Administrator tool for the configuration setting: Limit cache directory size to xx MB, the size of the cache directory in Seagate Info is limited to approximately 2 gigabytes. As a result, it is recommended that the cache directory size be limited to 1.5 to 1.75 gigabytes (GB). If a report generates a 2- gigabyte cache file, a problem will occur. NOTE This limit only applies to Seagate Info version 6 and does not apply to Seagate Info 7 (or other future releases). If the above setting is set to Unlimited (no limit has been set), the above 2 GB cache directory size limit does not apply. What is the difference between the SI Info APS and a post SI Info APS? In Seagate Info , when the Info APS reads from its own cache, it extracts a relatively small EPF file from the large EPF file and asks the Info Sentinel to send the file. The Info APS will clean up the small EPF files every 5 minutes. However, if the Info APS is shut down, the last 5 minutes worth of small EPF files are not deleted; so, those small EPF files are actually written permanently to the hard drive. In post-si , the Info APS will delete the files on exit, and it will ask the Info Sentinel to delete the files when it is done with them. When the report instance is being deleted (SI ), the cache files are only deleted if there is an available Info Agent running. In post Seagate Info , the Info APS tries to delete them itself first. Why are no cache pages ever created if the Cache Limits is set to "0"? Is this by design? If the Report Cache Page Limit is set to "0", cache pages are actually created in the Cache directory and then deleted. The process is very quick; so, you will not see any files physically appearing and disappearing in that directory. This is true both at scheduling time and at view time. What happens in the case of Drill Down? If the Cache Page Limits are set to 1, one cached page will be available for drilling down upon request. If the Cache Page Limits are set to Unlimited, all of the pages available for drill-down are cached. This is normal behavior. If the Cache Page Limits 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 13

14 are set to 1 and a drill down of a large size is attempted, users might experience some delay in viewing the requested Drill Down pages (as only one drill down page will be generated per request). Are drill-down.epf files created during report processing or during report viewing? Drill down EPF files are NOT created during report processing (regardless of the EPF configuration settings). They are created at report viewing time; as a result, the drilldown operations in the Info Viewer will create a NEW.EPF file the first time the drilldown is attempted. Currently, when drill down is initially selected, the request is sent to the Info Agent to generate all the pages on the drilldown report (up to the number of pages specified in the Cache Page limit). An enhancement request (which has been forwarded to our developers) is to return the first drilldown page to the viewer and then generate the rest of the requested pages in the background (to be served to the viewer as they are requested). This would return the first drilldown page to the viewer more quickly than is now the case. In the cache directory, what does each file extension represent?.epf : Encapsulated Page Format (.EPF) is a concatenated version of the.epf files for each page. This file stores report pages ready for viewing..etf : stores the group tree information, basically, the left-pane of the Info Viewer..crh: stores information about the cache files. You should see one for the.etf files and another one for the.epf file. This file is generated by the Info APS after it has already added reference of the.epf and the.etf into its memory. [This file is also used by the Info APS to build the cached table on startup.].rdp: stores group paging information (stores which page each group is in)..rdx : stores where each page is located within the.epf file. In the Info Configuration Manager, under the Info Servers tab, there are two configuration options for the Info Agent; they are: Maximum Number of Threads In the Info Agent and Maximum Job Load. How are these settings to be used? NOTE Seagate Info 6 has two configuration options: Maximum Number of Threads in the Info Agent and Maximum Job Load. However, Seagate Info 7 only has 1 configuration option for the Info Agent called Maximum Info Agent Job Load. The threads are handled internally by the Seagate Info 7 product. This question is best answered by first framing the answer with some technical background. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 14

15 When a report has been requested, the Info Agent uses the Seagate Info Print Engine (CIPE) to generate the.epf or.htm files. The Print Engine is actually the Cipe32.dll. It is the print engine s function to open and close the report file upon request. If, for example, two requests for the same report have been made, that report (.RPT) would normally have to be opened and closed for each view request. The saved data in.rpt files is compressed; in order to open the.rpt, the data must be decompressed. Depending on the size of the data, the act of decompressing the data could take a relatively long time. The ratio of compression is 1:10 to 1:15; therefore, it could take a while for a report to open. If the.rpt is to be opened and closed for each view request, the second request cannot be served until the.rpt is closed for the first request and the.rpt is re-opened for the second request. In a multi-user environment, constantly opening and closing the report could take what might prove to be an inordinate amount of time. If the.rpt file could be left open while other view requests are made, the time between the closing and opening of the report for each request would be saved. This would make the response time for each view request shorter. Each opened report takes up lots of disk space; so, leaving all of the reports opened will eventually impact system resources. Some balance must therefore be achieved between: a) the number of reports it is desirable to have open at one time and b) the available system resources and disk space. Maximum Job Load specifies the number of jobs that can be opened by the Info Agent. Jobs are kept open to improve the performance of page-on-demand report viewing from the Info Desktop or WebAccess desktops. The Maximum Job Load tells the Info Agent how many reports should be left opened. The higher the number, the less likely the Info Agent will have to open a.rpt file (it speeds up viewing requests on the same report). This means more disk space is required. Maximum Number of Threads in the Info Agent controls how many things the Info Agent can do (i.e. number of reports that it can process) at the same time. If it is "1", it means that the Info Agent won't start the next request until the first one is done. Having a higher number means that the Info Agent might start another request sooner. The actual tangible benefit (with respect to processing speed) of tweaking this option may not be noticeable. Even though the setting for the Maximum Number of threads can be increased, processing is still spread over the same number of CPUs. If this setting is increased, the wait time for all the requests will be averaged out. In addition, the greater the number of threads that are running, the greater the memory and disk space usage will be. What is a Thread? A thread is the most basic unit of code that can be executed. A thread can be thought of as a lightweight version of a program. The way in which an Operating System (OS) handles multiple programs in order to make them run at the same time (sometimes referred to as multitasking) is very much the way an (OS) handles threads. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 15

16 What is Multithreaded? Multithreaded means that an application\library can perform more than one task at the same time (i.e. it has more than one thread). In the case of Seagate Info, the following components are all multithreaded: Info APS, Info Agent, Report Agent and the Print Engine (CIPE). What is thread-safe? The concept of Thread-Safe can be approached by looking at an independent component such as a library (e.g..dll), which might be utilized during the execution of several different threads. Thread-safe means the library will not be affected by what might be happening with respect to the execution of any one particular thread. If one thread fails for some reason, that failure will not be carried over to any of the other threads in a thread safe environment. The Seagate Info Print Engine (CIPE) is threadsafe. When Maximum Number of Threads in the Info Agent is set to "1" in the Info Configuration Manager, six threads appear in the Performance Monitor. Why is this? The default setting of 1 under Maximum Number of Threads in the Info Agent in Seagate Info 6 controls how many worker threads are in the Info Agent. All the other threads are there to help the worker threads. Because the worker threads are the ones that are actually responsible for generating the.epf files, they are often referred to singularly as threads in the Info Agent. When a thread is being executed, it executes as part of a bundle of threads. This bundle can be viewed as consisting of a main or worker thread and a number of supporting threads which perform administrative tasks while the worker threads are busy processing. The Info Agent only has a limited number of worker threads, created on start-up. They are all stored in a "pool of free threads". This pool of Free Threads is created based on the Maximum Number of Threads in the Info Agent setting (which is found in the Info Configuration Manager under the Info Servers Tab). How does the Info Agent open a separate thread for each request? The Info Agent doesn't open a "separate thread for each request". It will find an available thread from its pool of free threads and assign the request (and the report file) to the thread. Moreover, for the lifetime of the Info Agent, all requests for that same report will ALWAYS go to the same thread. How will the Info APS manage this many threads accordingly and are there any limitations? The Info APS only manages Info Agents. When there is a request, the Info APS finds the Info Agents and forwards the request. The Info Agent manages the working threads and simply keeps track of whether the threads are free or active. The threads are relatively inexpensive to manage with respect 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 16

17 to resource overhead. In addition to threads, the Info Agent also keeps track of the number of reports that are opened. The maximum number can be set in the Info Configuration Manager > Info Server tab, under Maximum Job Load. What is the role of the Info APS in the page on demand process during.epf generation? The Info APS acts as the front line for any EPF request. When the Info Viewer receives a request for an EPF, it directs the request to the Info APS. The Info APS will look at its own cache, and if it cannot find the file, it will ask the Info Agent to generate it. When the Info Agent finishes generating the EPF, it will reply to the Info APS. The Info APS will store the file and then send the requested cached page back to the viewer. If the Info APS already has the report pages cached, it will send the page requested to the viewer directly. Why does it take so long for the report to process at scheduling time (it is so quick to process in the Report Designer)? At scheduling time, the procedure that is followed is: Resolve\Read the location of the original report object to open the report file. Connect to the database and retrieve the data from the database. Export the data to the.rpt file Generate the page-on-demand cache files for page-on-demand viewing (based on the Cache Page Limits setting defined globally or for the report object). This can take some time depending on the complexity of the report, levels of drill down, selection formulas, etc. NOTE The final step in the schedule process (above) usually takes the longest to complete. To exactly compare benchmarking times of running a report in the Report Designer versus at scheduling time, follow these steps below. Benchmarking in the Report Designer: 1. Start timing. 2. Right-click on the report object on the Info Desktop and choose Design. This will open the Report in the Report Designer. 3. Refresh the report by clicking on the lightning bolt button. Page to the last page in the report, as this will ensure that all data is in fact retrieved; in addition, this will ensure that any subreports that exist in the report are in fact executed. 4. Under the File menu, turn on the option for Save Data with Report. 5. Click on File > Save. 6. Stop the Time. Benchmarking at Schedule Time: 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 17

18 7. Right-click on the report object on the Info Desktop and choose Properties > Limits in Seagate Info 7. (For version 6 users, choose the option Object Limits. Ensure that the Cache Pages limit is set to "0" for this report. 8. Right-click on the report object on the Info Desktop and choose Schedule. Fill in the required information and when ready click on the Schedule button. 9. Start timing when the report begins to process. (This is accomplished by examining when the scheduled report instance status changes to Processing on the Info Desktop.) 10. Stop the time when the instance status changes to Success. NOTE Ensure that for this benchmarking that only 1 concurrent report is allowed to process at a time. This setting is found in the Info Administrator > Info Servers > Maximum Load. The suggested setting for Max Number of threads for the Info Agent in SI 6 is less than 10. What types of errors will be received if this threshold is exceeded? There will definitely be degradation of performance. In addition, Windows NT has an upper limit for the number of opened handles allowed. As more threads are opening reports, more handles are opened; eventually Windows NT will complain and an error will be returned. The error returned depends on which handle cannot be opened. If the Info Agent is busy with another request, where is the request queued? The requests are queued on the Info Agent. Is there a message indicated on the Info Viewer if the Info Agent is busy? No. Currently, the Info Viewer will wait until the Info Agent replies. Is there a way to send a message to effectively cancel the cache processing request [from the viewer]? In Seagate Info version 6, no. This had been sent as an enhancement request to the development team. The SI Enhancement Track ID is This has been addressed in version 7 of Seagate Info. An architectural change has been made to the product to allow for this. Now, the job results are cached. When does the Info Agent close a report? Does it close the report when it sends the File back to the Viewer? The Info Agent does not close the report after it handles the request. When it opens a new report, if the number of opened reports exceeds the number set in the Info 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 18

19 Configuration Manager > Info Server Tab > Maximum Job Load, then the least used report job is closed. Since the Info Agent is based on one thread per report, is it true that the number of threads must equal the number of reports one wishes to run simultaneously? No. The 1 thread per report does not imply 1 report per thread. A thread can open more than 1 report; for example, if you have 10 threads, you can have more than 10 reports open at the same time. If there are multiple computers that can be used for caching, and one Info Agent caches pages because of the Cache Page limit setting (or because Drill Down was performed on a report), the cached pages will be stored in memory on that computer. If the same page is requested by another user, it is served to the user in a timely manner but the files do not appear to be written anywhere. If the first Info Agent ceases to function, another Info Agent will process the requests but the cache files will have to be reprocessed. Why is that? There are actually two levels of caching: EPF caching and Report print job caching. EPF Caching When the Info Agent is finished creating the EPF files, they are handed over to the Info APS. Once the Info APS has the EPF files, it makes no difference to those simply viewing the report whether or not the Info Agent is active. Report File Caching After the Info Agent is finished with EPF generation, the Info Agent hangs on to the report and the drill-down report. This saves the Info Agent having to re-load everything again in the event that the user wants to do more processing. Why does the Info Agent need to hang on to the report? Saved data is stored in the.rpt file in compressed form. In order to open the report, the saved data needs to be expanded. The saved data from each opened report must be loaded into memory. If the size of the data is large, it could take a long time to decompress. The compression ratio is about 1:15. Why does the Info Agent need to hang on to the drill-down report too? When drilling-down, a record-selection is being performed on the saved data and as a result, new pages will be created. The Info Agent then makes a copy of the result set. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 19

20 Why is viewing an old instance slower than viewing a new instance? When an old instance is viewed again, why is viewing it then fast? The EPF files for the old instance have been deleted to make room for the new instance. Once the old instance is viewed again, the EPF files have been regenerated and so viewing performance is fast again. Does the regeneration process take a long time? For the Info Agent to generate the report, the right side should be relatively fast, however, generation of the group tree requires running through the entire report. The length of time it takes the Info Agent to regenerate the report depends largely on the report size and complexity; the more groups in the report the longer it will take to generate. How can I make sure that is what s happening? Check to see if the Info Agent is actually loading the old instance output file. Right click on the report instance in the Info Desktop and take note of its instance name (i.e. ~cixxx.rpt). Double-click on the Info Agent icon in your task bar. Is this the name of the instance that the Info Agent has open? NOTE If the Info Agent is running as an NT service, the above verification process will not be an option as NT Services do not generate the GUI interface that NT Processes do). What can I do to make the report regenerate faster? Increase cache size. Increase available system resources (faster and more powerful computer with a large hard drive). Is there a way to check that all of the cache files were created for a particular report instance? Unfortunately, the answer is no. The.rdp,.rdx, and the.epf files have the same file name. The.etf and.crh files have their own unique names. How does the cache directory size setting work and what impact is there on both run time and viewer performance? After the Info APS gets the EPF files from the Info Agent, it tallies the total size of the cache directory. If the cache directory exceeds the maximum size in the Info Administrator, the least used EPF files are removed from the directory until the size is within the limit. For run time: There is no impact. For view time: With a larger cache directory size, more EPF files can be accommodated, which means more pages can be cached and viewing will be faster. A smaller cache size 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 20

21 means that fewer pages can be cached and at some point, requested pages will have to be generated thereby making the viewing time longer. How does the Cache page limits per report object setting work and what impact is there on both run time and viewer performance? Larger cache page limits means it takes longer to generate, but it will seem faster for the viewers. What performance issues can be expected with varying report size, number of groups, record\group selections, formulas, and table joins? The general rule is the larger the report; the slower it gets, because of the time it takes to open the report. More groups in the report also translate into longer processing times. Increasing the complexity of the record\group selections will increase the processing time. Keep in mind that the saved data is not indexed. If the selection is complex, then the Seagate Info Print Engine has to go through every record and see if each record should be included. If this is compounded by the report being large, the processing time will be longer. What clean-up operation takes place with respect to the following: a) Deleting instances, b) stopping the Info Agent and Info APS, and c) resetting the Cache Directory size? Deleting instances will delete the output file. In version , the.epf files are not deleted when the instance is deleted unless an Info Agent is available and running. In version and later, the Info APS will attempt to delete the.epf files when the instance is deleted. If the.epf file is not otherwise in use, deletion of the.epf file will be successful. When the Info Agent is stopped, all the open jobs will be closed. All the temporary files created by the Info Agent will be removed, but the EPF files will not be removed. When the Info APS is stopped, nothing is deleted. When the Info APS starts up, it will read the cache directory, and extract the EPF file cache from there. When the cache size is reset, subsequent changes in the cache directory will be adjusted for by the Info APS. Does the Info Agent have to generate all pages, before it can display a specific page? The pages are not really completely generated; in order to know what a specific page is to be comprised of, the end of each page must be determined. Some processing for each page must be performed but just enough to know what a specific page should consist of. 7/8/2002 3:52 PM Copyright 2001 Crystal Decisions, All Rights Reserved. Page 21