Using Geodatabase Replication To Manage Distributed Data David Best Redwood National Park Craig Dalby Pacific West Regional Office 2008 GIS & Data Management

Using Geodatabase Replication To Manage Distributed Data

David BestRedwood National Park

Craig DalbyPacific West Regional Office

2008 GIS & Data Management Conference

National Park ServiceU.S. Department of the Interior

Redwood National ParkPacific West Region

The “Problem”

• A great challenge is how parks will obtain and edit national GIS datasets.

• Options include moving data (and applications) to national servers, or…

• Keeping data local, and pushing changes to national datasets




Centralized Data

• Field (remote) users give up local applications and local data in favor of Remote Desktop/Citrix, or…

• Repeatedly download and upload data between local servers and national servers

Few organizations have the network bandwidth to accommodate local applications directly editing remote data




Typical NPS Environment

• For most parks there is a dramatic performance improvement when working with local data.

• Local data makes it easier to customize user interfaces, more efficiently access other data stored on park servers, and integrate data of park-only interest.




Geodatabase Replication• It is inconvenient to move data back and

forth from the edit (local server) and integrated (national server) environments.

• ArcGIS 9.2 introduced new technology for this problem: Distributed Geodatabase.

• Allows versioned SDE geodatabases to be deployed at multiple locations.

• Changes are synchronized with replica versions using either one-way or two-way replication.




Benefits• A park can house and maintain data for

a specific geographic area, gaining the performance of “local” data.

• Seamlessly, these data contribute to national datasets.

• Changes made at either the parent (EGIS) or park (child) can be replicated to the other.

• This allows parks and programs to retain stewardship responsibilities, while ensuring an authoritative national versions are maintained.




Need to Evaluate• Geodatabase Replication is new –

want to test stability and reliability • NPS computing environment is

diverse – want to test suitability in small parks with no IT support and large parks with dedicated GIS specialists and servers




PWRO Project Funds

• Participating Parks:Redwood Lassen Volcanic

Lava Beds Oregon Caves

Sequoia-Kings Pacific West RO

• Had to overcome reluctance. Difficult for a park to see benefit.

• Common question: what am I going to have to do?




Objectives

• Collect and enter building footprints• Develop methods and procedures to install and

configure two-way replication• Implement two-way replication and train park

staff• Evaluate performance and make

recommendations for EGIS use.

Can an out-of-the box standardized ArcSDE deployment be seamlessly and consistently deployed to park offices?







General Steps

1. Install SQL Server

2. Install SDE

3. Perform SDE post-install

4. Configure using Access Database

5. Create Replica on child

6. Schedule Synchronization

Configure Two-way Replication

• MS Access database with embedded VB code is used to automate:

– Record information about location, IP addresses, server name, database locations

– Create new Active Directory groups for administration, editing, and viewing park-based EGIS data

– Create folders/shares for administrative files– Create SDE connection files– Enable SQL backup– Implement SQL database roles and AD

security










1




2

OTHER PARKSLassen Volcanic

PWRO

Lava Beds

Redwood

EGIS

Database Produces Consistent Share Name with AD Security





3

Create database EGIS(SDE created by SDE install)

Create logins for•Administrators•Editors•Viewers

Set permissionsfor SDE and EGIS databases

Create Database Roles:•Editors•Viewers

Connects to EGIS database as the LABE SDE user on the park’s SDE server

Connects to parks version on the EGIS database as the LABE SDE user on the EGIS serverEGIS

EGIS Database Park Version as park SDE use

PARK EGIS Database Default Version as park SDE user



4




SDE Connection Files Can Be Read By ArcCatalog



Right-click to view“ConnectionProperties”



Connection Properties



5



6



7

Lassen Volcanic

PWRO

Lava Beds

OTHER PARKS

Automated Backup of SQL Databases Are Consistent





8




Python Script for Synchronization




Create Replica on Child

• In most cases an EGIS responsibility• Data is mainly “pulled” instead of

“pushed”.• No need to disclose EGIS security to

parks. • ArcMap provides spatial filter to limit

replica to park’s geographic area (not available in ArcCatalog)

• Filters are great way to eliminate versions and posting



Activate Distributed Geodatabase Toolbar

Load data that will participate in replica into map

Specify Type of Replica

Specify Connection and Replica Name

REPLICA OWNER PARENT CHILD

Use to limit geographic area where synchronization occurs. Useful for avoiding SDE versions

Use for trusted editors and offices with oversight responsibility

Specify Spatial Extent




Managing Replication• Synchronization can be manual or automated.• Synchronization begins for each park as a

separate task within “Schedule Tasks.”• The task is a batch (.bat) file that calls the

python script created earlier.

FROM “EGIS” TO:




Monitoring ReplicationRight click SDE database Distributed Geodatabase Manage

Replicas

Viewing the Replication Log

Replication Manager

Replication Log

Results and Recommendations

• Complete install about 3 hrs/server• Get Administrator access• Other Flavors of SQL/SDE probably not

worth coast savings• SQL backup very easy and reliable• SDE Service needs monitoring• Two-way replication avoids permission

management with versions• Replica design should be updatable• Infrastructure mostly adequate




Results and Recommendations

• Have not trained park users, but do not expect difficulties.

• Unforeseen benefit may be rapid-deployment of region or network-based integrated datasets.

• Datastore should consider one-way “data subscription” service for national datasets not edited by parks.

• Annotation is an easy and very useful national test dataset.




Next Steps

• Complete Klamath Network Parks.• Encourage frequent park editing.• Review by EGIS Team.• Add new theme.• Move parent to RIMD.• Work on VPN solution.• ELA for SQL Server.• New participants?




Documents

Using Geodatabase Replication To Manage Distributed Data David Best Redwood National Park Craig Dalby Pacific West Regional Office 2008 GIS & Data Management