'concurrency' error from service when trying to save a second task - concurrency

Question

I'm trying to save two tasks to the same user story. The first request always succeeds, but the second service request always gets this message back in the response:
Concurrency conflict: [Object has been modified since being read for
update in this context] - ConcurrencyConflictException : Modified
since read on update : Object Class : com.f4tech.slm.domain.UserStory
: ObjectID :
I am using the JavaScript SDK to create the task. I do this twice:
Rally.data.ModelFactory.getModel({
type : 'Task',
success : function(task) {
var record = Ext.create(task, {
Name : taskName,
State : 'Defined',
TaskIndex : 1,
WorkProduct : workProductId,
Owner : userIdsTeam[owner],
SyncDevelopmentTasktoAccuRev : accuSync,
Estimate: hours,
TargetDeployment: targetDeployment,
context: {
project:'/project/' + currentProjectId,
projectScopeDown: true
},
});
record.save({
callback : afterSaveNewTaskCallback
});
}
});
Is there anything I can do to get rid of this error and successfully save two tasks?

Answer 1

In addition to Kyle's answer, you can also use the Rally.data.BulkRecordUpdater to have the creates/updates queued for you. http://developer.rallydev.com/apps/2.0p5/doc/#!/api/Rally.data.BulkRecordUpdater

Answer 2

Since your tasks are both attached to the same underlying user story the creates are both trying to lock on it to set the association and that's why the second one fails. You'll need to chain the callbacks together:
Rally.data.ModelFactory.getModel({
type : 'Task',
success : function(taskModel) {
//Create first task
var task1 = Ext.create(taskModel, {
//...fields...
});
task1.save({
callback: function() {
//Create second task
var task2 = Ext.create(taskModel, {
//...fields...
});
task2.save({
callback: afterSaveNewTaskCallback
});
}
});
}
});