© 2009 IBM Corporation Confidential ® 1 IBM P8 CE 4.x Storage Overview Bob Kreuch, CEMP/CFS Development Team February 3, 2009

© 2009 IBM Corporation Confidential

®

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IBM P8 CE 4.x Storage Overview

Bob Kreuch, CEMP/CFS Development TeamFebruary 3, 2009


Information Management software | Enterprise Content Management

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Outline

1. Document & Content Object Overview

2. Storage Areas

Database, File System, Fixed

3. Storage Policies

4. Storage Area Resource Status

5. Fixed Storage Devices

Image Services, Centera, SnapLock, IICE



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Section 1 – Document/Content Model Overview

ContentTransfer objects

contain content that is

managed by CEMP

Documentobject ContentElements

(set of obejcts)

ContentTransferobject

ContentReferenceobject

ContentReference objects contain

a reference to content (for example,

an HTTP address) that is not

managed by CEMP

Each Document (or Annotation)

contains a set of zero or more

ContentElement objects



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Document Object

Properties

Content

Object Store Database Tables

Storage Area

Document [or Annotation] object

contains properties and content

Document

Property values

are stored in

the Object Store

database tables

Content is stored

in a Storage Area



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Content Elements

Properties

Content

Object Store Database Tables

Storage Area

All content for a given

Document is stored in a

single Storage Area

Document

Content Element 0

Content Element 1

Content Element 2

Most applications (like

Workplace) only support a

single [ContentTransfer]

content element

The content is exposed

to applications as a set of

(zero or more) Content

Element objects



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Document Version Series

Properties

Content

Document

A reservation object is a

new document object,

created from the previous

version of the document

Version 1

Properties

Content

Reservation

Reserved

Checkout

Properties

Content

Document

Version 2

Checkin

When a reservation is

checked in, it becomes the

next version of the

document (the reservation

is transformed, a new

object is not created)



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Immutable Content Element

A Content Element is immutable in that once the content is committed to CEMP, the content cannot be altered (it can only be deleted). This applies to the content of Documents in the checked-in state and in the reservation state, and to the content of Annotations.

Content is always stored precisely as it is received from the client (byte for byte), CEMP does not alter the content, add formatting or header data, etc.



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Immutable Content Element Set

The Content Element set for a given Document in the checked-in state is immutable, no new elements can be added to the set, and no existing element can be removed from the set.

The Content Element set for a Document in the reservation state is mutable. Existing elements can be removed from the set, and new elements can be appended to the set (but a new element cannot replace an existing element – a new element is appended to the end of the set using a new sequence number). Annotations follow the same rules as a Document in the reservation state, since they do not support versioning.



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Section 2 – Storage Areas

CEMP Supports Three Types of Content Storage Areas

• Database [DatabaseStorageArea]

• File System [FileStorageArea]

• Fixed (External) [FixedStorageArea]

• Native Content

• Federated Content



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Database Storage Area

Each Object Store has a built in Database Storage Area, which is automatically created when the Object Store is created.

PROS:

Easy to use, no configuration is necessary, security issues are handled by security on the Object Store database. Backed-up as part of the Object Store Database backup. Excellent performance for small to medium sized content.

CONS:

May not be a suitable storage mechanism for large volumes of immutable content (or very large content elements).



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Database Storage Area – Content Element Database Row

CONTENT table ELEMENT_ID EXTENSION CONTENT CONTENT_SIZE CREATE_DATE

Content Element RowObject Store Database

Content data bytes

(blob column)

{bc2d1fc8-d78e-4e48-bc7b-7ef96d1e97b8}0

Optional file extension of the

source file (for example, ‘pdf’ for

a file named ‘mydocument.pdf’)

Unique ID of the element,

Document object_id + element

sequence number

Size of the

content data in

number of bytes



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Database Storage Area – Document with Three Elements

CONTENT table

ELEMENT_ID EXTENSION CONTENT CONTENT_SIZE CREATE_DATE

Content Element Row (element 0)

Object Store Database










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File System Storage Area

A file system based storage area uses a standard NTFS or UNIX file system to store content (CIFS and NFS protocols are supported).

PROS:

Supports large content and very large volumes of content - any number of areas may be created for an Object Store, content may be randomly distributed across the areas during creation.

CONS:

Must be managed independently from the database (security configuration, space management, backup and restore, etc.).



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File System Storage Area – Directory Structure

Storage Area Root Folder

Inbound Content

Stakefilefn_stakefile.xml

FN0 FN1 FN22

FN0 FN1 FN22

FN0 FN1 FN22

ContentFile

The root folder is created by a system

administrator

The stakefile provides verification that a storage area is really the correct area

The inbound folder provides temporary storage for content while it is uploaded

to the area

Content that has been ‘finalized’ is stored under the content folder hierarchy

An area has either two (small) or

three (large) levels of subfolders

(used to distribute the content across

the file system namespace)

Content is stored in a file, under the lowest level of the subfolder hierarchy (each content element is stored in a separate file)

Content is not stored in the upper levels of the subfolder hierarchy



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File System Storage Area – Content Element File

FN0(Lowest Level Subfolder)

Content Element File

FN{E15E8CAB-3A03-427E-AAF7-610F3BBA63C5}{35A02CFA-C069-4038-ABB3-A70F981A56EB}-0.html

Filename Prefix

(always ‘FN’)

Object Id of the

Document or

[Annotation] object

Object Id of the

Storage Area

Content Element

sequence number

Filename

extension



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File System Storage Area – Document with Three Elements

FN0(Lowest Level Subfolder)

Content Element File (element 0)








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File System Storage Area – Remote File System

File System Storage Area

CEMP Server

CEMP Server CEMP Server

The computer that hosts the storage area is remote from the CEMP Server, to avoid data loss (during content upload), it must have a UPS power backup or support some form of file write through



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Unix File System Based Area – NFS Export


The root folder is

exported via NFS

CEMP Server Instance 1


The root folder is

mounted using NFS

on each CEMP

server system

CEMP servers

access the file

storage area over

the network



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Unix File System Based Area – Security

CEMP Server Instance

(Deployment)

J2EE Application Server

UNIX CEMP User Account

The CEMP server runs under the context of a UNIX

user account (call it the CEMP user account)

Create Folder Folder ‘Inbound’

The permissions on the folder being created are determined by the creation mask (a.k.a. umask) of the user account that CEMP is running under (the CEMP user account)

CEMP user umask: u=rwx,g=rwx,o=

Resulting Permissions:USER: read/write/execute

GROUP: read/write/executeOTHERS: no access



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NTFS Based Area – CIFS Share


The root folder is shared

as a CIFS shared folder

(optionally, a DFS link

may be used to provide

name transparency)



The root folder, and all

subfolders and files, are

accessed via a UNC

path (mapping the

shared folder is optional)

CEMP servers

access the file

storage area over

the network



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NTFS Based Area – Security

CEMP Server Instance

(Deployment)

J2EE Application Server

Windows CEMP User Account

The CEMP server runs

under the context of a

Windows user account (call

it the CEMP user account)

Create Folder Folder ‘Inbound’

The permissions applied to folders and files is based on inheritance from the root folder. Once the root folder is created with the proper permissions and inheritance settings, all other folders and files the correct values.

* The CEMP user account is granted full control, either directly or via group membership.* Other administrative users may be granted full control.* Unwanted inherited/inheritable permissions are removed.



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Fixed Storage Area

A fixed storage area is a CEMP concept used to write content to and retrieve content from an external repository. A fixed storage area consists of four major components, 1) an external repository, 2) a CEMP fixed content device object, 3) a CEMP fixed storage area, and 4) a CEMP fixed content provider implementation.

PROS & CONS:

It’s assumed that a customer has a business case for using an external repository, and that the business case is the overriding factor in the decision to use the external repository (the pros & cons of using the external repository end up being a moot point).



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Fixed Storage Area – Supported External Repositories

• IBM FileNet Image Services

• Network Appliance SnapLock

• EMC Centera

• IBM IICE (Content Services, CM8)



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Fixed Storage Area Components

CEMP Fixed Device

Object

External Repository(a.k.a. Fixed Device)

The CEMP Fixed Device object contains configuration data that

is used by the Fixed Content Provider to connect to and

update the External Repository

Fixed Content Provider

CEMP Server

Fixed Storage Area(a.k.a. Staging Area)

The Fixed Content Provider software uses the client API of the external repository to create, retrieve, and delete external content

An external repository is accessed through the CEMP API as a Fixed Storage Area – the repository cannot be accessed without a corresponding Fixed Storage Area

External Repository Client API



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Fixed Storage Area – Back it Up!

A Fixed Storage has an associated ‘staging area’ that is really a File Storage Area, which needs to be

administered as a storage area (configured as a shared network

resource, data must be backed up, must have a UPS power backup, etc.)

Fixed Storage Area(a.k.a. Staging Area)

Content is first uploaded to the inbound folder of the Fixed Storage Area, then finalized to the content folder – after it’s finalized, it will be written (a.k.a. migrated) to the external repository

The staging area provides storage for content of documents that are queued for migration, that are in the reservation state (including annotations), and for new versions of federated content of non-writable external repositories



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Fixed Storage Area – Referral Blob Creation



During migration to the external repository, the Fixed Content

Provider receives a reference to the content (for example, a Image

Services docid) Content Reference

DocVersion row

referral_blob column

Referral Blob

The Fixed Content Provider generates a referral blob from

the content reference data

The referral blob is stored as a column of the document row, in the DOCVERSION table


The Fixed Content Provider migrates content to the external

repository (copy & delete source)

1

2

3 4



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Fixed Storage Area – Retrieval using Referral Blob



The Fixed Content Provider obtains the referral blob data from the

DocVersion row, then uses the data to retrieve the content,

streaming the data to the client

DocVersion row


CEMPClient




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Fixed Storage Area – Referral Blob Format

Provider Id & Software Version

Checksum

Type Flags

Content Id (GUID of the Document)

Common Referral Header

Image Services DocId

Content Element (IS Page) Count

Content Element Sequence Number

Image Services Page Number

RepositorySpecific

DataContent Element to IS Page Mapping (one entry for each content element)



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Fixed Storage Area – Federated Content


CEMP Server

The CEMP import agent creates federated content,

using the CEMP API

DocVersion row


Referral Blob

The content to be federated already exists in the external repository

The referral blob can be used to retrieve, delete, or lock down the external content

CEMP Import Agent

Content

The CEMP server computes the referral blob, based on data received from the application, and inserts the blob into the DocVersion row



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Fixed Storage Area – Creating Federated Content

x-FileNetFCS:?docid=2005083&pagenum=1&mode=3

Fixed header, indicates federated content.

External document identity

Content element identity

CEMP APIContentTransfer.setCaptureSource()



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Section 3 – Storage Policies

Storage Policy

Storage Area A

Storage Area B

Storage Area C

A Storage Policy can point to multiple Storage Areas,

using a selection filter (SQL statement syntax)

An open Storage Area is randomly selected for content storage (the content is only stored in a single area)



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Determining the Storage Area for a Document

DocumentClass

Default Storage Area

Default Storage Policy

DocumentInstance

Storage Area

Storage Policy

A Document Class has a default storage area and a default storage policy (one or the other is required)

CEMP Client API

First Document in the Version Series

The storage area and policy is normally inherited

from the document class, but can be set directly via

the CEMP client API

Setting the area/policy is optional in the API



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Storage Area/Policy Order of Precedence

The Storage Area or Policy applied to the first document of a version series is selected in the following order (the first value that is set will be used):

1) Storage Area set directly on the Document via the API.

2) Storage Policy set directly on the Document via the API.

3) Default Storage Area on the Document class.

4) Default Storage Policy on the Document class.



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Selecting a Storage Area Based on a Policy

DocumentInstance

Storage Area

Storage Policy

First Document in the Version Series

A Storage Area is randomly selected from the Storage Policy, and set as the StorageArea property on the Document

Storage Area Selection



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Determining the Storage Area for a Reservation

DocumentInstance

Storage Area

Storage Policy

DocumentInstance

Storage Area

Storage Policy

A reservation inherits the storage area and policy of the

previous version of the document (the storage area will

always set on the previous version, the policy may or may

not be set)

CEMP Client API

Reservation based on version 1 of the

Document

Given that the area takes precedence over the

policy, the policy is normally ignored when creating a reservation

The area may be set via the API when the reservation is created (to force content for the new version of the document to be stored in a specific storage area).

Version 1 Reservation



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What if the Previous Storage Area is Full/Closed?

DocumentInstance

Storage Area

Storage Policy

DocumentInstance

Storage Area

Storage PolicyCEMP Client API

Reservation based on version 1 of the

Document

If the storage area of the previous document is no longer open, the storage

policy will be used to select a different storage area

Version 1 Reservation

Storage Area Selection

A Storage Area is randomly selected from the Storage Policy, and set as the StorageArea property on the Document

Note that if the storage policy doesn’t include an area that can be used for new content, creation of the reservation will fail



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Section 4 – Storage Area Resource Status

All Storage Areas have an associated Resource Status value that controls which content operations are allowed for the area, as seen in the table below.

Resource Status

Create New Content

Append Content

Delete Content

Retrieve Content

OPEN Yes Yes Yes Yes

CLOSED No No Yes Yes

STANDBY No Yes Yes Yes

FULL No No Yes Yes

Note that ‘Append Content’ means ‘add new content to an existing document that’s in the reservation state’.



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Automatic Resource Status State Transitions

CEMP supports three types of automatic resource status transitions (the server automatically changes the resource status for an area).

From Status

To Status

Comments

OPEN FULL Occurs when adding a content element detects that the size/count exceeds the maximum allowed.

OPEN CLOSED Occurs when adding a content element detects that the closure date is in the past.

STANDBY OPEN Occurs when adding a content element detects that there are no OPEN areas in the storage policy, but there is a standby area in the policy.



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Storage Area Counters and Limits

The following Storage Area properties are used to determine when to automatically transition the resource state of an area.

Property Name Description

ContentElementCount Number of content elements currently in the area.

ContentElementKBytes Total k-bytes currently used by all content elements in the area.

MaximumContentElements Maximum number of content elements allowed before the area is marked full.

MaximumSizeKBytes Maximum k-bytes (all content elements) allowed before the area is marked full.

ClosureDate Date when the area is to be marked closed.



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Manual Resource Status State Change

The Resource Status may be manually changed, according to the following rules:

The resource status may be changed to CLOSED, FULL, or STANDBY without restriction, the counters/limits/closure date do not restrict changing ‘to’ any of those states.

A manual status change to OPEN (including from open to open) is allowed only if the size/count is below the limits and the closure date is in the future (or isn’t being used).



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Section 5 – Fixed Storage Devices



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Image Services Content Storage

CEMP Document

Content Element 0

Content Element 1

Doc ID

Element 0=Page 1

Element 1=Page 2

Referral Blob

Doc ID

Page 1 Content

Image Services Document

All content for a single CEMP document is stored

as a single Image Services document, identified by an

IS Doc ID

The content of each element is stored as a separate page of the IS document

Page 2 Content



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SnapLock Content Storage

CEMP Document

Content Element 0

Content Element 1

File ID

Element 0 = File 1

Element 1 = File 2

Referral Blob

A GUID is generated for each CEMP document, that

GUID is used to form the unique file name of the

SnapLock file

The content of each element is stored as a separate file within the folder hierarchy

S0

Content File 2Content File 1

A SnapLock fixed device is a folder hierarchy on a

SnapLock volume



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Centera Content Storage

CEMP Document

Content Element 0

Content Element 1

C-Clip ID

Element 0 = Tag A

Element 1 = Tag B

Referral Blob

C-Clip ID

C-Clip Name

Tags

Content Blob A Content Blob B

Centera Object

All content for a single CEMP document is stored as a single Centera object,

identified by a C-Clip ID

The content of each element is stored as a separate content blob of a tag of the C-Clip