- What's New
- Function Overview
- Service Overview
- Getting Started
-
User Guide
- Permissions Management
- Supported Data Sources
- Creating and Managing a CDM Cluster
-
Creating a Link in a CDM Cluster
- Creating a Link Between CDM and a Data Source
-
Configuring Link Parameters
- OBS Link Parameters
- PostgreSQL/SQLServer Link Parameters
- GaussDB(DWS) Link Parameters
- RDS for MySQL/MySQL Database Link Parameters
- Oracle Database Link Parameters
- DLI Link Parameters
- Hive Link Parameters
- HBase Link Parameters
- HDFS Link Parameters
- FTP/SFTP Link Parameters
- Redis Link Parameters
- DDS Link Parameters
- CloudTable Link Parameters
- MongoDB Link Parameters
- Cassandra Link Parameters
- DIS Link Parameters
- Kafka Link Parameters
- DMS Kafka Link Parameters
- CSS Link Parameters
- Elasticsearch Link Parameters
- Dameng Database Link Parameters
- SAP HANA Link Parameters
- Shard Link Parameters
- MRS Hudi Link Parameters
- MRS ClickHouse Link Parameters
- ShenTong Database Link Parameters
- LogHub (SLS) Link Parameters
- Doris Link Parameters
- YASHAN Link Parameters
- Uploading a CDM Link Driver
- Creating a Hadoop Cluster Configuration
-
Creating a Job in a CDM Cluster
- Table/File Migration Jobs
- Creating an Entire Database Migration Job
-
Configuring CDM Source Job Parameters
- From OBS
- From HDFS
- From HBase/CloudTable
- From Hive
- From DLI
- From FTP/SFTP
- From HTTP
- From PostgreSQL/SQL Server
- From DWS
- From SAP HANA
- From MySQL
- From Oracle
- From a Database Shard
- From MongoDB/DDS
- From Redis
- From DIS
- From Kafka/DMS Kafka
- From Elasticsearch or CSS
- From MRS Hudi
- From MRS ClickHouse
- From a Dameng Database
- From LogHub (SLS)
- From a ShenTong Database
- From Doris
- From YASHAN
- Configuring CDM Destination Job Parameters
- Configuring CDM Job Field Mapping
- Configuring a Scheduled CDM Job
- Managing CDM Job Configuration
- Managing a CDM Job
- Managing CDM Jobs
- Viewing Traces
-
Key Operation Guide
- Incremental Migration
- Using Macro Variables of Date and Time
- Migration in Transaction Mode
- Encryption and Decryption During File Migration
- MD5 Verification
- Configuring Field Converters
- Adding Fields
- Migrating Files with Specified Names
- Regular Expressions for Separating Semi-structured Text
- Recording the Time When Data Is Written to the Database
- File Formats
- Converting Unsupported Data Types
-
Tutorials
- Creating an MRS Hive Link
- Creating a MySQL Link
- Migrating Data from MySQL to MRS Hive
- Migrating Data from MySQL to OBS
- Migrating Data from MySQL to DWS
- Migrating an Entire MySQL Database to RDS
- Migrating Data from Oracle to CSS
- Migrating Data from Oracle to DWS
- Migrating Data from OBS to CSS
- Migrating Data from OBS to DLI
- Migrating Data from MRS HDFS to OBS
- Migrating the Entire Elasticsearch Database to CSS
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Best Practices
-
Tutorials
- Creating an MRS Hive Link
- Creating a MySQL Link
- Migrating Data from MySQL to MRS Hive
- Migrating Data from MySQL to OBS
- Migrating Data from MySQL to DWS
- Migrating an Entire MySQL Database to RDS
- Migrating Data from Oracle to CSS
- Migrating Data from Oracle to DWS
- Migrating Data from OBS to CSS
- Migrating Data from OBS to DLI
- Migrating Data from MRS HDFS to OBS
- Migrating the Entire Elasticsearch Database to CSS
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Advanced Data Migration Guidance
- Incremental Migration
- Using Macro Variables of Date and Time
- Migration in Transaction Mode
- Encryption and Decryption During File Migration
- MD5 Verification
- Configuring Field Converters
- Migrating Files with Specified Names
- Regular Expressions for Separating Semi-structured Text
- Recording the Time When Data Is Written to the Database
- File Formats
- Scheduling a CDM Job by Transferring Parameters Using DataArts Factory
- Enabling Incremental Data Migration Through DataArts Factory
- Creating Table Migration Jobs in Batches Using CDM Nodes
- Simplified Migration of Trade Data to the Cloud and Analysis
- Migration of IoV Big Data to the Lake Without Loss
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Tutorials
- Performance White Paper
- Security White Paper
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- Application Example
-
API
-
Cluster Management
- Querying Cluster Details
- Deleting a Cluster
- Querying All AZs
- Querying Supported Versions
- Querying Version Specifications
- Querying Details About a Flavor
- Querying the Enterprise Project IDs of All Clusters
- Querying the Enterprise Project ID of a Specified Cluster
- Query a Specified Instance in a Cluster
- Modifying a Cluster
- Restarting a Cluster
- Starting a Cluster
- Stopping a Cluster (To Be Taken Offline)
- Creating a Cluster
- Querying the Cluster List
- Job Management
- Link Management
-
Cluster Management
- Public Data Structures
- Permissions Policies and Supported Actions
- Appendix
-
FAQs
-
General
- What Are the Differences Between CDM and Other Data Migration Services?
- What Are the Advantages of CDM?
- What Are the Security Protection Mechanisms of CDM?
- How Do I Reduce the Cost of Using CDM?
- Will I Be Billed If My CDM Cluster Does Not Use the Data Transmission Function?
- Why Am I Billed Pay per Use When I Have Purchased a Yearly/Monthly CDM Incremental Package?
- How Do I Check the Remaining Validity Period of a Package?
- Will My Data Be Retained If My Package Expires or My Pay-per-Use Resources Are in Arrears?
- Can CDM Be Shared by Different Tenants?
- Can I Upgrade a CDM Cluster?
- How Is the Migration Performance of CDM?
- What Is the Number of Concurrent Jobs for Different CDM Cluster Versions?
- Can I Stop a CDM Cluster?
-
Functions
- Does CDM Support Incremental Data Migration?
- Does CDM Support Field Conversion?
- What Component Versions Are Recommended for Migrating Hadoop Data Sources?
- What Data Formats Are Supported When the Data Source Is Hive?
- Can I Synchronize Jobs to Other Clusters?
- Can I Create Jobs in Batches?
- Can I Schedule Jobs in Batches?
- How Do I Back Up CDM Jobs?
- What Should I Do If Only Some Nodes in a HANA Cluster Can Communicate with the CDM Cluster?
- How Do I Use Java to Invoke CDM RESTful APIs to Create Data Migration Jobs?
- How Do I Connect the On-Premises Intranet or Third-Party Private Network to CDM?
- Does CDM Support Parameters or Variables?
- How Do I Set the Number of Concurrent Extractors for a CDM Migration Job?
- Does CDM Support Real-Time Migration of Dynamic Data?
- Can I Stop CDM Clusters?
- How Do I Obtain the Current Time Using an Expression?
- What Is the Time Format for the Where Clause Parameters for Creating a Migration Job?
- Can CDM Migrate Field Comments from a Source Table to a Destination Table?
-
Troubleshooting
- What Should I Do If the Log Prompts that the Date Format Fails to Be Parsed?
- What Can I Do If the Map Field Tab Page Cannot Display All Columns?
- How Do I Select Distribution Columns When Using CDM to Migrate Data to GaussDB(DWS)?
- What Do I Do If the Error Message "value too long for type character varying" Is Displayed When I Migrate Data to DWS?
- What Can I Do If Error Message "Unable to execute the SQL statement" Is Displayed When I Import Data from OBS to SQL Server?
- What Should I Do If the Cluster List Is Empty, I Have No Access Permission, or My Operation Is Denied?
- Why Is Error ORA-01555 Reported During Migration from Oracle to DWS?
- What Should I Do If the MongoDB Connection Migration Fails?
- What Should I Do If a Hive Migration Job Is Suspended for a Long Period of Time?
- What Should I Do If an Error Is Reported Because the Field Type Mapping Does Not Match During Data Migration Using CDM?
- What Should I Do If a JDBC Connection Timeout Error Is Reported During MySQL Migration?
- What Should I Do If a CDM Migration Job Fails After a Link from Hive to GaussDB(DWS) Is Created?
- How Do I Use CDM to Export MySQL Data to an SQL File and Upload the File to an OBS Bucket?
- What Should I Do If CDM Fails to Migrate Data from OBS to DLI?
- What Should I Do If Error "Configuration Item [linkConfig.createBackendLinks] Does Not Exist" or "Configuration Item [throttlingConfig.concurrentSubJobs] Does Not Exist" Is Reported?
- What Should I Do If Message "CORE_0031:Connect time out. (Cdm.0523)" Is Displayed During the Creation of an MRS Hive Link?
- What Should I Do If Message "CDM Does Not Support Auto Creation of an Empty Table with No Column" Is Displayed When I Enable Auto Table Creation?
- What Should I Do If I Cannot Obtain the Schema Name When Creating an Oracle Relational Database Migration Job?
- What Should I Do If invalid input syntax for integer: "true" Is Displayed During MySQL Database Migration?
- What Should I Do If the Migration Source Is Oracle and Error Message "snapshot too old" Is Displayed?
- What Should I Do If Error "Identifier name is too long" Is Reported During Entire DB Migration to Hive?
- What Should I Do If Data Is Lost During Migration to DLI?
- What Should I Do If the Oracle Link Connectivity Test Is Successful on the Link Creation Page but Fails on the Links Page?
- What Should I Do If Destination Fields Are Not Displayed When Auto Table Creation Is Enabled in the Destination Job Configuration?
- What Should I Do If a Job Exported from a Cluster Fails to Be Imported to Another Cluster?
- What Should I Do If an Error Message Is Displayed Indicating that the Block Is Missing During HDFS File Migration?
- What Should I Do If the CDM Job Management Page Cannot Be Accessed and a Message Is Displayed Indicating that the Network or Server Cannot Be Accessed?
- What Should I Do If a CDM Cluster of Version 2.8.6 Fails to Migrate Data from OBS to DLI?
- What Should I Do If Error Message "Read timed out" Is Displayed During DWS Data Migration?
- What Should I Do If No Database or Table Information Can Be Obtained Through a Hive Link?
- What Should I Do If Error "get filesystem" Is Reported During the Creation of a FusionInsight HDFS Link?
- What Should I Do If Error "Invoke DLI service api failed" Is Reported When the Data Migration from MySQL to DLI Is About to Complete?
- What Should I Do If a MongoDB Field Fails to Be Migrated to the Destination?
- What Should I Do If a Field Is Escaped and Contains a Backslash (\) During the Migration of a DLI Foreign Table (OBS File) to DWS?
- What Should I Do If "Error occurs during loader run" Is Reported During Migration from PostgreSQL to Hive?
- What Should I Do If Error Message "Lost connection to MySQL server during query" Is Displayed During Migration from MySQL to DWS?
- What Should I Do If Error Message "For input string: "false" Is Displayed During Field Type Conversion During MySQL-to-DLI Migration?
- What Should I Do If an Error Occurs During the Migration of TINYINT Data from MySQL to DWS?
- What Should I Do If the Data Volume Is Inconsistent Before and After Data Migration?
- What Should I Do If an Error Is Reported Indicating an Incorrect Username or Password During Link Creation but They Are Correct Indeed?
- What Should I Do If a Message Is Displayed Indicating that the Fields in the Lower Camel Case Do Not Exist During Data Migration from a Database to OBS?
- What Should I Do If Error "invalid utf-8 character string" Is Reported When CSV Data Is Inserted into the MySQL Database?
- What Should I Do If a Scheduled Job Fails and Link Connectivity Is Abnormal?
- What Should I Do If CSV Data Fails to Be Inserted into a MySQL Database?
- What Should I Do If Error "timeout waiting for connection from pool" Is Reported During ES Writing?
- Why Is Error ORA-01555 Reported During Migration from Oracle to DWS?
- What Should I Do If the FTP Connectivity Test Fails and an Internal Server Error Is Reported?
- What Should I Do If All Users Except User root Cannot Access RDS for MySQL?
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General
- General Reference
Show all
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Scenario
Consulting company H uses CDM to import local trade statistics to OBS, and Data Lake Insight (DLI) to analyze trade statistics. In this way, company H builds its big data analytics platform at an extremely low cost, allowing the company more time to focus on their businesses and make innovations continuously.
Background
Company H is a commercial organization in China that engages in collecting trade statistics of major trading nations and buyer data. It has a large-scale trade statistics database. The collected data is widely used in industry research, international trade promotion, and other fields.
In the past, company H used its own big data cluster with maintenance by dedicated personnel. Each year, company H purchased the dedicated bandwidth from China Telecom and China Unicom and invested heavily in equipment room, electric power, private networks, servers, and O&M. However, the company could not satisfy customers' ever-changing service requirements due to insufficient workforce and limited capabilities of its big data cluster. As a result, only 4% of 100 TB inventory data was useful.
After migrating local trade statistics to Huawei Cloud, company H can make full use of the 100 TB inventory data in maximizing asset monetization, without the need of constructing and maintaining infrastructures but relying on Huawei Cloud's big data analysis capabilities.
CDM and DLI use the pay-per-use billing mode, so maintenance personnel are not required and the dedicated bandwidth cost is reduced. Compared with the offline data center, CDM and DLI save the maintenance cost by 70%. In addition, CDM and DLI have low skill demands for personnel and enable smooth migration of existing services, shortening the service rollout period by 50%.
Task
Use CDM, OBS, and DLI to complete trade statistics analysis using the existing data (for example, trade detail records and basic information) of company H's customer data collection and processing system.
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- When you use the DataSource syntax to create an OBS table, the ORC, Parquet, JSON, CSV, Carbon, and Avro formats are supported.
- When you use the Hive syntax to create an OBS table, the Text file, Avro, ORC, SequenceFile, RCFile, Parquet, Carbon formats are supported.
If the storage format of the raw data table does not meet the requirements, you can use CDM to import the raw data to DLI for analysis without uploading the data to OBS.
Data Types
- Trade detail records
Trade detail records include trade statistics of major trading nations.
Table 1 Trade detail records Field Name
Field Type
Field Description
hs_code
string
List of import and export offering code
country
smallint
Basic information about countries
dollar_value
double
Transaction amount
quantity
double
Transaction volume
unit
smallint
Measurement unit
b_country
smallint
Basic information about the target country
imex
smallint
Import or export
y_year
smallint
Year
m_month
smallint
Month
- Basic information
The basic information indicates the dictionary data corresponding to the fields in the trade detail records.
Table 2 Basic information about countries (description of country) Field Name
Field Type
Field Description
countryid
smallint
Country code
country_en
string
English name of a country
country_cn
string
Chinese name of a country
Table 3 Information about the update time (description of updatetime) Field Name
Field Type
Field Description
countryid
smallint
Country code
imex
smallint
Import or export
hs_len
smallint
Length of the offering code
minstartdate
string
Minimum start time
startdate
string
Start time
newdate
string
Update time
minnewdate
string
Last update time
Table 4 Information about import and export offering code (description of hs246) Field Name
Field Type
Field Description
id
bigint
ID
hs
string
Offering code
hs_cn
string
Chinese name of an offering
hs_en
string
English name of an offering
Table 5 Information about units (description of unit_general) Field Name
Field Type
Field Description
id
smallint
Measurement unit code
unit_en
string
English name of a measurement unit
unit_cn
string
Chinese name of a measurement unit
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