Bulk API 2.0 and Bulk API Developer Guide

Introduction to Bulk API 2.0 and Bulk API
Bulk API 2.0
Bulk API
How Bulk API Works
Quick Start: Bulk API
Bulk API Ingest
Plan Bulk Data Loads
Install cURL
Walkthrough Sending HTTP Requests with cURL
Step 1: Log In Using the SOAP API
Step 2: Create a Job
Step 3: Add a Batch to the Job
Step 4: Close the Job
Step 5: Check Batch Status
Step 6: Retrieve Batch Results
Prepare Data Files
Load Binary Attachments
Request Basics
Work with Batches
Bulk API Query
Headers
Limits
Bulk API Reference
Sample Client Application Using Java
Map Data Fields
Bulk API End-of-Life Policy
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Step 1: Log In Using the SOAP API

The Bulk API doesn't provide a login operation, so you must use SOAP API to log in.
To establish a session, you need to use SOAP API’s login() function as described in the SOAP API Developer Guide:

The login() function returns an XML response that includes <sessionId> and <serverUrl> elements. Note the values of the <sessionId> element and the first part of the host name (instance), such as yourInstance-api, from the <serverUrl> element. Use these values in subsequent requests to the Bulk API.