em 404 new mobilink technology jim graham director of engineering ianywhere solutions...

EM 404 New MobiLink Technology

Jim GrahamDirector of EngineeringiAnywhere [email protected]

Outline

• Quick MobiLink review

• 8.0 New feature highlights

• MobiLink futures

MobiLink

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C om m unication Infrastructure( In ternet / D ia l-up / W ire less )

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MobiLink Design Goals

• Heterogeneous consolidated database

• Scalable and robust (tens of thousands)

• Manageable in large deployments

• Support handheld and wireless devices

• Flexible

How Synchronization Works

• 1. Upload• ASA or UltraLite keep track of all changes since

previous synchronization

• All changes are sent in a single upload stream

• MobiLink applies changes in a single transaction

• 2. Download• Scripts in the consolidated database determine changes

that need to be downloaded

• All changes are sent in a single download stream

• 3. Acknowledge download

MobiLink Synchronization

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MobiLink Scripts

• begin_connection

• for each synchronization:• begin_synchronization

• receive and apply upload stream

• prepare and send download stream

• end_synchronization

• end_connection

• Scripts define actions performed at the consolidated database at each stage or event during synchronization

8.0 New Feature Highlights

• Last download timestamp

• Statement-based uploads

• Java synchronization logic

• Better remote ASA terminology

• Selective uploads (priority synchronization)

• Improved reporting

7.0 Download Cursor

• The download_cursor script is used to insert or update rows in the remote database

SELECT emp_id, emp_fname, emp_lname FROM employee WHERE last_modified > @LastDownload

• The download_deletes_cursor script is used to delete rows from the remote database

SELECT emp_id FROM employee WHERE last_modified > @LastDownload AND status = ‘INACTIVE’

8.0 Last Download Timestamp

• The download_cursor script is used to insert or update rows in the remote database

SELECT emp_id, emp_fname, emp_lname FROM employee WHERE last_modified > ?

• The download_deletes_cursor script is used to delete rows from the remote database

SELECT emp_id FROM employee WHERE last_modified > ? AND status = ‘INACTIVE’

Last Download Benefits

• Last download time automatically stored in remote ASA or UltraLite database and provided to scripts during subsequent upload

• Less reliance on RDBMS functionality• Performance

• Usability

• No longer need download ack• Immediate commit of download transaction

The upload_cursor Script

• The upload_cursor script is used to insert, update, or delete rows in the consolidated database

• This is the primary script for uploading changes

• Example:

SELECT emp_id, emp_fname, emp_lname FROM employee WHERE emp_id = ?

Statement-based Upload Scripts

• The upload_insert script is used to insert rows

DELETE FROM employee WHERE emp_id = ?

INSERT INTO employee (emp_id, emp_fname, emp_lname) VALUES ( ?, ?, ? )

• The upload_update script is used to update rows

UPDATE employee SET emp_fname = ?, emp_lname = ? WHERE emp_id = ?

• The upload_delete script is used to delete rows

Statement-based Conflicts

• The upload_fetch cursor for conflict detection

• The insert_old_row script is used to insert the row from the remote database before the update

• The insert_new_row script is used to insert the row from the remote database after the update

• The resolve_conflict script is used to resolve the conflict

Statement-based Benefits

• More understandable

• Array operations improve performance• Single statement with multiple parameter sets

• Stronger ODBC support

Java Synchronization Logic

• Synchronization scripts written in Java rather than the native language of the consolidated database

• Single Java class defines the synchronization logic for a complete synchronization

• One public method for each event (Java method replaces SQL script)

• Java methods are passed the same parameters as SQL scripts (table, user, last download)

• Different classes can be used for different versions

Java Synchronization Logic

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Java Details

• MobiLink Java API support classes

• Write your Java class and compile it

• Make your Java class available to MobiLink

• MobiLink runs Java synchronization logic in the standard Sun VM (JRE 1.3 installed)

• One instance of your class is instantiated for each MobiLink connection to the consolidated database

• One public method of your class is called for each event in the synchronization process

• Methods can return SQL strings

Java Example

public class SalesSync { private DBConnectionContect _cc; public SalesSync( DBConnectionContext cc ) { _cc = cc; } public String EmpDownload( String user, Timestamp ts ) { String sql = “SELECT emp_id, emp_fname, emp_lname ” + “FROM employee WHERE last_modified >= ‘” + ts + “’”; return sql; }}

Java Example

• javac -classpath c:\sa\java\mlscript.jar;.; Sales.java

• call ml_add_java_table_script( “Sales 1.0”, “employee”, “download_cursor”, “SalesSync.EmpDownload” )

• dbmlsrv8 -c “dsn=cons” -o out.txt -sl java {-classpath .;}

Java Flexibility

• MobiLink JDBC bridge allows access to the database connection MobiLink is using to synchronize data

• Ability to create additional connections to the consolidated database or to another database

• Java instance variables share data across events

• Java static variables share data across connections

• java.lang.system.out.println to MobiLink output log

• Full power of standard Java VM

• Can mix Java and SQL synchronization logic

Java Benefits

• Works around limitations in native procedural languages of RDBMS

• Allows synchronization logic to be more portable across multiple RDBMS products

• Well known mainstream language that is well suited to procedural logic

• Re-use business logic

• Better debugging tools available

7.0 ASA Client Terminology

• Reference database

• Synchronization template

• Synchronization site

• mlxtract.exe

• Synchronization definition

8.0 ASA Client Terminology

• Publication

• Synchronization user

• Synchronization subscription

CREATE PUBLICATION SalesSync ( TABLE employee );CREATE SYNCHRONIZATION USER sally TYPE ‘tcpip’ ADDRESS ‘host=SalesServer’;CREATE SYNCHRONIZATION SUBSCRIPTION TO SalesSync FOR sally;

New Terminology Benefits

• Simpler, easier to understand

• Closer to SQL Remote

• Groundwork for other new features• Multiple publications and subscriptions per user

• Selective uploads

• Use MobiLink to populate data

• Still a bit backwards

Selective Upload

• Multiple publications and subscriptions

• Publications can overlap

• ASA or UltraLite can synchronize one or more publications at the same time

• Articles in publications can identify a subset of the rows in a table using a WHERE clause

• ASA publications can identify a subset of the columns in tables (all publications must have same column list)

• UltraLite does not support column subsets

High Priority Synchronization

CREATE PUBLICATION SalesSyncHigh ( TABLE “order” WHERE priority = ‘high’, TABLE order_item i WHERE ‘high’ = (SELECT priority FROM “order” o WHERE o.id = i.id ) );CREATE PUBLICATION SalesSync ( TABLE employee, TABLE “order”, TABLE order_item );

Selective Upload Scenarios

• High priority wireless synchronization with lower priority cradle or LAN synchronization

• Nightly synchronization with more frequent synchronization throughout the day

• Request-based downloads

• Multiple applications using a common database

Selective Upload & Last Download

• Downloads have always been selective

• Separate last download timestamp kept for each publication in remote database• Each synchronization, MobiLink uses the earliest last

download time for all publications being synchronized

• Could mean redundant download

Improved Reporting

• New statistics events to record upload and download statistics (rows, errors, warnings, bytes)

• Upload dbmlsync output log following an error

• More detailed information following an error

More 8.0 New Features

• Automatic script generation

• sa_migrate

• Limit worker threads applying upload streams

• Database connection timeout

MobiLink Futures

• Message-based communication

• Java synchronization logic to non-relational enterprise application servers

• MobiLink monitor console

Resources Available

• Other TechWave sessions

• MySybase: Mobile & Wireless Developer• newsgroups, white papers, technotes, FAQs

• samples, patches

• Award winning technical support

• Training and assistance during the initial phases of your synchronization projects

iAnywhere Solutions Highlights

• Ask the Experts - about Mobile & Wireless Solutions-Mezzanine Level Room 15B Mon./Tues. 11:30 am - 3:30 pm; Wed. 11:30 - 1:30;Thurs. 9 am - 12 noon-Exhibit Hall - Demo Center (truck) exhibit hall hours

• SIG (Special Interest Group)- Tuesday 5:30pm Mobile & Wireless SDCC, Upper level, Room 11

• Keynote - Enabling m-Business SolutionsWednesday 1:30 pm - 3:00 pm

• iAnywhere Solutions Developer Community-Excellent resource for commonly asked questions, newsgroups, bugfixes, newsletters, event listings - visit www.ianywhere.com/developer

em 404 new mobilink technology jim graham director of engineering ianywhere solutions...

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