Using the custom logic sample application

After you have enabled the custom logic policies, you can use the sample application. The following steps involve the use of several DB2 Everyplace applications and tools:

• IBM Sync
• DB2eCLP

Procedure

The file paths used in this example are Windows specific and the variable %DSYINSTDIR% is the directory where DB2 Everyplace is installed. For UNIX, replace %DSYINSTDIR% with $DSYINSTDIR.

• Use IBM Sync to refresh the initial data on your device (user=nurse1, password=nurse1)
• Use DB2eCLP to view the data in your VNMEDICALRECORD table. The schema of this table is:
  • RecordID integer primary key
  • Date_C date
  • Time_C time
  • PatientID char(9) NOT NULL
  • BloodPressure char(7)
  • PulseRate smallint
  • Temperature decimal(4,1)
  • Weight decimal(5,2)
  • Comment varchar(100)
• Use DB2eCLP to insert a medical record
  • CLP:> insert into vnmedicalrecord values (1000, current date, current time, '900000001', '140/85', 80, 100.01, 145.50, 'CL statistic');
• Use IBM Sync to synchronize the vnmedicalrecord medical records with the data source
  • During synchronization, DB2 Everyplace custom logic writes the log messages to STDOUT if you are using BeforeTableSyncIn, TableSyncIn and AfterTableSyncIn policies. STDOUT is recorded in the file %DSYINSTDIR%\Server\logs\DB2eServer\native_stdout.log (search for the strings "TableSyncInPolicy", "BeforeTableSyncInPolicy", "AfterTableSyncInPolicy").
  • Replication occurs periodically every 60 seconds. During replication, custom logic writes the log messages to STDOUT if you are using Before Database Replicate, Before Table Replicate, Table Replicate, After Table Replicate and After Database Replicate policies.
• Use DB2eCLP to insert a medical record
  • CLP:> insert into vnmedicalrecord values (-1001, current date, current time, '900000001', '140/85', 80, 100.01, 145.50, 'CL primary key change');
• Use DB2eCLP to review this newly created record. Note the primary key value is -1001.
• Use IBM Sync to synchronize this medical record with the data source. Several operations take place:
  • During synchronization, custom logic writes the log messages to the STDOUT showing that it has mapped the primary value -1001 to 1001.
  • When synchronization stops, use DB2eCLP to view the newly created medical record. Note that the primary key value has been changed to 1001. Here is the reference to the sample Custom Logic code which performs this change:

    %DSYINSTDIR%\Server\sample\src\com\ibm\mobileservices\sample
        \VNurseCL\VNurseTableSyncInPolicy.java
    

  • Wait for the periodic replication. During the replication, custom logic writes the log messages to the STDOUT informing that the new record with the new primary key value 1001 is replicate to the source.
  • When the replication ended, verify that the source contains the new record with the primary key value 1001.
• To see how you can use custom logic for conflict resolution, you must change periodic replication to replication on demand:
  • Start the Mobile Devices Administration Center.
  • Edit the Visiting Nurse subscription (JDBCSUB1)
  • In the Advanced Replication Subscription, select Define subscription and then Timing. Change 60 to 0.
• Insert a medical record in the VNURSE data source as follows:
  • insert into dsysample.vnmedicalrecord (1002, current date, current time, '900000001', '140/85', 80, 100.01, 145.50, 'CL conflict source data');
• Use DB2eCLP to insert a medical record
  • CLP:> insert into vnmedicalrecord values (1002, current date, current time, '900000001', '140/85', 80, 100.01, 145.50, 'CL conflict resolution - winner').
• Use IBM Sync to synchronize this medical record with the data source.
• Perform a manual replication
  • Locate and invoke, %DSYINSTDIR%\Server\bin\dsyreplicate.bat M_VN2.
  • During the replication, the Custom Logic writes to the STDOUT informing that it detects there is a conflict and takes the decision to pick the winner from the user (instead of the default rule where the winner is from the source). Here is the reference to the sample Custom Logic code which performs this change

    %DSYINSTDIR%\Server\sample\src\com\ibm\mobileservices
    \sample\VNurseCL\VNurseTableReplicatePolicy.java
    

    . Use IBM Sync to synchronize again the result of the conflict resolution.

• Use IBM Sync to synchronize against the result of the conflict resolution.
  • Since both source and device inserted a conflicting record (with the same primary key 1002), the Custom Logic policy resolves the conflict by selecting the winner from the device "nurse1". This overrided the default conflict resolution algorithm which always selects the record from the data source as the winner. Here is the reference to the sample Custom Logic which performs this conflict resolution.
  • On the device, use DB2eCLP to see that the winner is the record inserted from the device
  • On the source, verify that the winner is the record inserted from the device.

Související úlohy

• Enabling the sample application for custom logic
• Developing custom logic

Related concepts

• Custom logic