life in the fast lane
TRANSCRIPT
Life In The Fast Lane Full Speed XPages
March , 21. – 22. 2013
Faculty Club, Leuven, Belgium
Ulrich Krause, BCC Unternehmensberatung GmbH
Matthew Fyleman, We4IT
Lotus Notes/Domino Developer since 1993
Senior Developer at We4IT GmbH
Recently focused entirely on XPages development
Working on We4IT's XPages framework
Also on Offline capabilities for We4IT’s mobile framework
About: Matthew Fyleman
Lotus Notes/Domino Developer since 1993
Senior Software Architect at BCC
OpenNTF Contributor
OpenNTF Board of Directors
IBM Champion 2011/2012/2013
Blog http://www.eknori.de
Notes Forum (http://www.atnotes.de)
About: Ulrich Krause
Performance, what factors affect it?
Java vs. JavaScript
Looping through Documents, ViewNavigator vs. GetNextDocument
Stringbuilder vs. Concat (+)
JSF Lifecycle Listener
Partial Update / Partial Execute
Variable Resolver
Tools
Agenda
XPages Request
The hardware used has a significant influence on performance. There are 3 key elements: • CPU
• Main Memory
• Hard Disk
Hardware
CPU • Cores / Clock / Cache
• Poor response time
Main Memory • Limit defined by the operating system
• Scalability
Weak CPU AND Low Memory • Poor overall performance
• Poor response times
• Server "hangs"
Hardware
Latency • Time taken for data transmission between multiple computers on a
network
Bandwidth • Rate of transmission of data
Greater Bandwidth + Lower Latency -------------------------------- = Better Connection
Network
Hardware
How many data requests / responses are transmitted
How much data is transferred (size)
Caching of resources
How much CSJS runs
Size / complexity of the CSS
Complexity of the site structure
Client & Browser
Browser / HTTP server • Network latency – distance/time to server. Bandwidth – size of files.
• Browser limits on concurrent downloads; <= IE7 allows 2 downloads, IE8 allows 6
HTTP Server / App Server • HTTP Server JVM memory allocation (heap size) & garbage collector
• CPU time, competition between threads, gives slower response times
• Threads, limited to 40 by default, configurable in Domino Administrator
App Server / Domino context • Read design elements from the NSF (XPage .class files, form structure, etc)
• Backend API calls may be expensive, especially for large data sets.
• Design elements may be network requests.
Limiting factors on performance
Servlet / Lifecycle • Restore control tree – file system read. Control tree locking – no
concurrent access.
• Rendered re-evaluated for every control for most phases
Browser/Client JavaScript/Dojo • Inline JavaScript blocks insertion of later HTML elements into the DOM
tree
• Dojo does AJAX requests for .js files for dojo modules that are not loaded
Limiting factors on performance
notes.ini • HTTPJVMMaxHeapSizeSet=1
• HTTPJVMMaxHeapSize=256M
• Should be set to ¼ of the available RAM
Domino Administrator • HTTP server "Enable logging to" disabled
• HTTP server thread count – defaults to 40
Remember, enabling the debugger affects performance • JavaEnableDebug=1
• JavaDebugOptions=transport=dt_socket,server=y,suspend=n,address=8000
• JavascriptEnableDebug=1
General Performance Options
xsp.persistence.mode=
Defines the persistence mode for the JSF pages • file: All the pages are persisted on disk
• fileex: All the pages are persisted on disk except the current one, which stays in memory
• <else>: All the pages stay in memory (tree mode)
Reducing Memory Utilization
Simple actions vs links or button with window.location JS
Reduce server phase processing • Use partial update where possible
• Use partial execute where possible
• Use disableValidators & immediate event
Minimize work in rendered / visible computations • Use variable resolver
Repeats & Views • Use viewEntry.getColumnValue instead of viewEntry.getDocument.getColumn
• Use Domino View data source dataCache property where possible
XPages Design Optimizations
Load-time vs Runtime • Using loaded vs rendered
• ExtLib Dynamic Content
– allows partial re-loading so more use of load-time optimizations
Loading resources in the browser • CSS & browser JS
– extract to separate files. Minify & compress files
• Images
– use correct size & format. Use CSS Image Sprites as possible
XPages Design Optimizations
Groups many DOJO, CSS / JS files into a single file • Less requests from the browser to the server
• Performance improvements on networks with high latency
• Enhanced performance parsing CSS / JS
• Fewer connections to the server
JavaScript/CSS Aggregation
On the Server: xsp.properties:
xsp.resources.aggregate=true
JavaScript/CSS Aggregation
XPagesPreload=1
New Feature in Notes / Domino 8.5.3
Server and Client
Java classes from the XPages runtime plug-ins • loaded from a fixed list of runtime classes ( 435 in ND 8.5.3 )
• com.ibm.xsp.core, common utility, JS wrapper, FSF runtime classes
Java classes referenced in *-faces.config.xml • XPages control renderer, data sources, complex types
XPages Pre-Load
• XPagesPreloadDB=Server!!Db.nsf/XPage.xsp, myLocalDb.nsf • Works at the application level
• The application is loaded on the client / server startup into memory. This happens even when the application is first opened in the browser
• For each entry in the notes.ini variable, an XPage URL is generated and sent to the server
• The application is loaded, and the HTML generated
• The XPages runtime discards the HTML, but retains the application in memory
XPages Pre-Load
applicationScope • Are visible for all users of one application. Expires some time after the last user
used an applicationScope variable. That means applicationScope variables are NOT persistent forever.
sessionScope • Is valid through the session of the current user. A user session expires after
some time of inactivity. Uses don't have access to the sessionScope variables of other users.
viewScope • Is visible for views on the current page only. Useful for transporting a search
query to a view.
requestScope • Is valid through one request of the current user. That includes refreshing of a
page.
Scoped Variables
Caching with Application Scope
JSF Lifecycle
XPages Lifecycle Listener
What happens in each phase of the JSF lifecycle?
Ulrich Krause: http://openntf.org/XSnippets.nsf/snippet.xsp?id=a-simple-lifecyclelistener-
XPages Masterclass
http://www.openntf.org/internal/home.nsf/project.xsp?action=openDocument&name=XPages%20Masterclass
#
• Executed every time the page is rendered
• Use for values that are likely to change
$ • Executed when the page is first loaded
• Use for values that don't change
When to Execute - # vs $
dataContexts can be thought of as global variables
dataContext's value can be computed dynamically or on page load • So you can use ${javascript:@Today()} and run it once rather than running
a function each time.
dataContexts can be scoped to any level that datasources can • XPage, Custom Control or Panel
• you can set a dataContext in a panel in a repeat control, to avoid multiple references to a NotesDocument's item
dataContexts are referenced using EL • So at no point in the references do you run SSJS, so it's not having to go
through the SSJS parser
DataContext
Issue with data context variables if they are bound dynamically. • They will be recomputed again and again, even when in Partial Execution
mode and if they are not in use (http://hasselba.ch/blog/?p=1112)
DataContext - Pitfall
DataContext - Pitfall
Reduced control processing in the render response phase • Means less work on the server
– render response is the most intensive phase
Smaller response from server. • means reduced network usage
Better browser experience • rest of the page is still visible while waiting for a response
• inserting small sections into the page is much faster than reloading a full page.
Partial Refresh / Update (Pro)
Dependancy outside of the partial update area • Other areas of the control tree are not processed,so any SSJS scripts in those
other controls will not be run.
• Enabling Partial Update where it was previously full update may lead to functional problems
Only one area may be partial updated by default • In CSJS you can schedule later partial updates of related areas, but any
concurrent requests will wait for exclusive access to the server-side control tree before processing on the server
Partial Refresh / Update (Cons)
http://www.timtripcony.com/blog.nsf/d6plinks/TTRY-84B6VP
Reduced control processing in the 3 data-processing phases • Means less work on the server, faster response times
Dependancy on Edit Box values outside of the exec area • Submitted values from Edit Boxes and/or other input controls in other areas of
the control tree are not processed, so any control values and document fields in those other areas will not be updated. Enabling Partial Exec where it was previously full execution may lead to functional problems where values are out-of date in the onclick script or in the redisplayed page.
onclick Event Handler must be in the exec area • The applyRequestValues phase prepares for the invokeApplication phase.The
onclick simple action or SSJS script won't occur if outside the partial exec area
Partial Execution
execMode only added in 8.5.1 (not in 8.5.0)
execId slightly difficult to select in Designer • Select your button, in the Outline view, toggle open the button, select the child
Event Handler control, then set the execId property on the Event Handler.
• [Better UI proposed in Notes/Domino Next – in the Events tab]
Partial Execution
disableValidators • JSF life cycle through all phases (1-6)
• But requests will not validate the data
• Converters continue to work.
• Items in documents will be updated
• Sven Hasselbach - "Disable all validators at once" (http://hasselba.ch/blog/?p=1106)
• Immediate • JSF Lifecycle processes only phases (1, 2, 6)
• No data processing
• Items in documents are not updated
• Onclick event handler scripts and render response calculations are performed
disableValidators / immediate
Most properties, like CSS “style” are only computed in the renderResponse
Edit Box and input “value” properties are used in Data Processing phases & renderResponse
Data Source properties are computed during renderResponse & results are cached for the next request's Data Processing & invokeApplication phases
Minimize work in rendered / visible computation
The rendered property is computed in all 5 lifecycle phases
Avoid re-computing values in every rendered property
• @DbLookup, @DbColumn, getDocumentByKey
• In the rendered property, save the computed boolean to a viewScope variable
Minimize work in rendered / visible computation
Loaded • is only computed once in the createView phase
• not re-computed in the 5 usual phases
• false means the control is not created. So it can never be rendered.
• true means the control is added to the control tree.
• You can still compute rendered when loaded evaluates to true.
Compute the loaded property on conditions • where you could compute the rendered property and save it to the view
scope
• it would never need to be recomputed for the rest of the interaction with this page
Using loaded vs rendered
Use correct file type depending on content • JPEG for complexed detailed images
• PNG/GIF for simple images, fonts, transparencies
• Use the HTML <img> tag “width” and “height” attributes
• For faster HTML layout in the browser
• Size the image to size you intend to use
• Resizing using html attributes height and width will delay the rendering of your page
• Images larger than necessary will waste bandwidth
Images
Use CSS Image Sprites • If you have multiple small images, make a single larger image containing
the smaller images
• And use CSS to display just the relevant subset image at a location in the page
• For semantically significant sprites, provide an accessibility “title” attribut (as sprites don't use the IMG “alt” attribute, but you still want to assist blind users)
• There's no specific XPages support for sprites, but they're used in the XPages OneIU themes
CSS Image Sprites
CSS Image Sprite Sample
http://www.w3schools.com/css/tryit.asp?filename=trycss_sprites_img
XPages based Application • Runs on the Domino server or the Notes client
• An NSF needs to be installed on the Domino server/Notes client
• A profiler jar file should be added to the JVM launch options
Measures the CPU performance and the memory allocation
Available from OpenNTF.org • Free open source project
• Search for “XPages Toolbox”
Extended in 8.5.2 to support Backend classes profiling
XPages Toolbox
http://www.openntf.org/internal/home.nsf/project.xsp?action=openDocument&name=XPages%20Toolbox
XPages Toolbox
Generate a heap dump of the JVM running in the HTTP task • A button in the XPages profiler generates the heap dump
• From the Domino console
• tell http xsp heapdump (triggers com.ibm.jvm.Dump.HeapDump())
• tell http xsp javadump (triggers com.ibm.jvm.Dump.JavaDump())
Analyze the heap dump using the Eclipse memory analyzer • http://www.eclipse.org/mat/
• http://www.ibm.com/developerworks/java/jdk/tools/dtfj.html
XPages Toolbox
Heapdump / Javadump Analyzer
Print statements • In rendered/visible computations to see how often executed
– print("panel2 evaluating rendered property");
• In the XPages root control events:
– before/afterPageLoad, afterRestoreView, before/afterRenderResponse.
• Custom control root events:
– before/afterPageLoad.
• In the document data source events:
– queryNewDocument, postSaveDocument, etc.
Task Manager and/or Process Explorer • Shows CPU usage & process memory usage as it happens
• Heap memory usage will be a subset of process memory, but heap dumps are only a snapshot
More Tools
Browser developer tools • for watching network transactions, partial updates, response times
• BROWSER: Firebug, Developer Tools
• XPiNC: FirebugLite from ExtLib
Java / Javascript Debugging • Degrades performance but can inspect objects, step into code.
• Use the Eclipse Java debugger.
• In Domino\notes.ini add these 2 options:
• JavaEnableDebug=1
• JavaDebugOptions=transport=dt_socket,server=y,suspend=n,address=8000
More Tools
Demo
Get all „Contacts“ into a NotesDocumentCollection, loop the collection and build the JSON by reading the values from items in the document
XAgent – SSJS
XAgent – SSJS
Get all „Contacts“ into a NotesDocumentCollection, loop the collection and build the JSON by reading the values from items in the document. Also UNID is stored in document
XAgent – SSJS – UNID from Item
XAgent – SSJS – UNID from Item
Get all „Contacts“ into a NotesDocumentCollection, loop the collection and get the JSON from an item on the document. The JSON is calculated on document save
XAgent – SSJS - SingleItem
XAgent – SSJS - SingleItem
loop thru a view and get the JSON from a view column.
XAgent – SSJS – ViewNavigator
XAgent – SSJS – ViewNavigator
Concatenation of Strings is very easy in Java - all you need is a '+‘
Each time you append something via '+' (String.concat()) a new String is created, the old stuff is copied, the new stuff is appended, and the old String is thrown away. The bigger the String gets the longer it takes - there is more to copy and more garbage is produced.
Accordingly to Arno Unkrig the optimal strategy is to use String.concat() for 2 or 3 operands, and StringBuilder for 4 or more operands
StringBuilder vs String.concat
String text=
"line 1\n"+
"line 2\n"+
"line 3";
System.out.println("x:"+x+" y:"+y);
When to use StringBuilder over '+' (String.concat()) ? • use StringBuilder whenever you assemble a String in a loop
• Just keep in mind that '+' isn't always a good idea
StringBuilder vs String.concat
http://kaioa.com/node/59
loop thru a view and get the JSON from a view column. Use a StringBuilder to concat the JSON
XAgent – SSJS – ViewNavigator + StringBuilder
XAgent – SSJS – ViewNavigator + StringBuilder
loop thru a view and get the JSON from a view column. Use a StringBuilder to concat the JSON + use Java instead of SSJS
XAgent – Java
XAgent – Java
Single Document Containing References to all your CSS Resources • resource sections reference the CSS files used
• control section define what CSS classes are applied to specific controls
XML Based and Easy To Learn • creating a new theme document prefills sample content
Can Extend Other Themes • <theme extends="webstandard">
• will automatically include all the resource and control definitions from that theme
• built-in themes to extend
• webstandard, notes, oneUI
Themes
Create your own themes from scratch.
Creating a theme that extends from the webstandard or another supplied theme will include extra stylesheets and styles that you might not need.
Be prepared to spend more time writing css though
Themes
Global Application / Configuration properties
Load Resources from Theme
