Persistent Session Storage Henceforth referred to as PSS :) - - - PowerPoint PPT Presentation

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Feb 05, 2023 113 likes •592 views

MONTREAL JUNE 30, JULY 1ST AND 2ND 2012 Persistent Session Storage Henceforth referred to as PSS :) - Ramsey Gurley Demo MONTREAL JUNE 30, JULY 1ST AND 2ND 2012 What does this mean? Robust, scalable, front end apps using component actions.

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MONTREAL JUNE 30, JULY 1ST AND 2ND 2012

Persistent Session Storage

Henceforth referred to as PSS :)

Ramsey Gurley

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Demo

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MONTREAL JUNE 30, JULY 1ST AND 2ND 2012

Robust, scalable, front end apps using component actions.

What does this mean?

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Advantages of PSS

Memory consumption
Long sessions
Distribution

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Memory Consumption

Sessions storage handled by EOF
Session memory freed after each request
Drastically improves stateful performance under load

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Long Sessions

WOSessionTimeOut=0
Bookmarkable component actions

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Distribution

WOSession’s setDistributionEnabled()
Restart instances anytime
Improved scaling

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How do I enable PSS?

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Demo

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Steps to enable PSS

Add ERPersistentSessionStorage framework
Set up the connection dictionary for the model
Generate the schema from the model (Enable migrations)

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MONTREAL JUNE 30, JULY 1ST AND 2ND 2012

How now brown cow?

Why has no one done this before now?

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Serialization Bug

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EOGenericRecord

Serialize EO
Serializes EC
Deserialize EO
Deserialize EC
Populate EO

EO EC

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Workaround?

Serialize EC first!
Fails :(

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EOGenericRecord

Serialize EO
Serializes related
Deserialize EO
Deserialize related
Populate EO

EO EO

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What happens?

EOCustomObject classDescription
EOGenericRecord serializes classDescription
Deserialize EOCustomObject sets values
Dictionary not created until EOGenericRecord sets

classDescription

NullPointerException

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Serialization Bug Fix

Re-implement core classes
EOCustomObject
EOGenericRecord

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Other WO Serialization Erros

WODisplayGroup
D2WPage

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Serialization

Classpath order - ERD2W & ERPSS
General rule - Wonder first

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PSS Requirements

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PSS Requirements

Serializable components and classes
Serializable session
No memory leaks

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Serializable Classes

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serialVersionUID

/** * Do I need to update serialVersionUID? See section 5.6 <cite>Type Changes * Affecting Serialization</cite> on page 51 of the <a * href="http://java.sun.com/j2se/1.4/pdf/serial-spec.pdf">Java Object * Serialization Spec</a> */ private static final long serialVersionUID = 1L;

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Update serialVersionUID?

Change class hierarchy
Delete fields
Make non-static into static
Make non-transient into transient
Change type of a primitive field

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Serializable Session

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Serializable Session

Serializable instance variables
Serializable object store contents

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No Memory Leaks

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Helpful Tools

FindBugs
jvisualvm
jMeter

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Find Serialization Errors

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FindBugs

http://findbugs.cs.umd.edu/eclipse/

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FindBugs

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Serialization Debug Property

sun.io.serialization.extendedDebugInfo=true

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Serialization Debug Property

Caused by: java.io.NotSerializableException: er.extensions.localization.ERXLocalizer

field (class "er.modern.directtoweb.components.ERMDBatchSizeControl", name: "_localizer", ...
object (class "er.modern.directtoweb.components.ERMDBatchSizeControl",...
element of array (index: 5)
array (class "[Ljava.lang.Object;", size: 7)
field (class "com.webobjects.foundation.NSDictionary", name: "objects", type: "class [Ljava.lang.Object;")
custom writeObject data (class "com.webobjects.foundation.NSDictionary")
object (class "com.webobjects.foundation.NSMutableDictionary", ...
custom writeObject data (class "com.webobjects.appserver.WOComponent")
object (class "er.modern.look.pages.ERMODListPage", ...
field (class "com.webobjects.appserver._private.WOTransactionRecord", name: ...
object (class "com.webobjects.appserver._private.WOTransactionRecord", ...
element of array (index: 1)
array (class "[Ljava.lang.Object;", size: 2)
field (class "com.webobjects.foundation.NSDictionary", name: "objects", type: "class [Ljava.lang.Object;")
custom writeObject data (class "com.webobjects.foundation.NSDictionary")
object (class "com.webobjects.foundation.NSMutableDictionary",
field (class "com.webobjects.appserver.WOSession", name: "_contextRecords", ...
root object (class "wowodc.modernpss.Session", ...

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Other Serialization Issues

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D2WContext

D2WContext is not serializable
ERD2WContext is serializable
Use ERD2WContext factory

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ERD2WContext

Does not serialize entire context
frame
task
entity
propertyKey
pageConfiguration
object

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ERXEC

calls dispose() during writeObject()

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Find Memory Leaks

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jvisualvm

Installed with Java 1.6+
Just type ‘jvisualvm’ into Terminal.app to launch
View CPU and memory usage

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No Memory Leak

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Memory Leak

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Analyzing Memory

Heap Dump
Object Query Language (OQL)
http://visualvm.java.net/oqlhelp.html

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Load Testing With JMeter

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JMeter

http://jmeter.apache.org/

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Finding a Memory Leak Demo

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Persistent Session Storage

Demo

What does this mean?

Advantages of PSS

Memory Consumption

Long Sessions

Distribution

How do I enable PSS?

Demo

Steps to enable PSS

How now brown cow?

Serialization Bug

EOGenericRecord

Workaround?

EOGenericRecord

What happens?

Serialization Bug Fix

Other WO Serialization Erros

Serialization

PSS Requirements

PSS Requirements

Serializable Classes

serialVersionUID

Update serialVersionUID?

Serializable Session

Serializable Session

No Memory Leaks

Helpful Tools

Find Serialization Errors

FindBugs

FindBugs

Serialization Debug Property

Serialization Debug Property

Other Serialization Issues

D2WContext

ERD2WContext

ERXEC

Find Memory Leaks

jvisualvm

No Memory Leak

Memory Leak

Analyzing Memory

Load Testing With JMeter

JMeter

Finding a Memory Leak Demo

Q & A