How Do I Set the Number of Concurrent Extractors for a CDM Migration Job?
- When data migration jobs are submitted, CDM splits each job into multiple tasks based on the Concurrent Extractors parameter in the job configuration.
Jobs for different data sources may be split based on different dimensions. Some jobs may not be split based on the Concurrent Extractors parameter.
- CDM submits the tasks to the running pool in sequence. Tasks (defined by Maximum Concurrent Extractors) run concurrently. Excess tasks are queued.
Changing Concurrent Extractors
- The maximum number of concurrent extractors for a cluster varies depending on the CDM cluster flavor. You are advised to set the maximum number of concurrent extractors to twice the number of vCPUs of the CDM cluster.
Table 1 Maximum number of concurrent extractors for a CDM cluster Flavor
vCPUs/Memory
Maximum Concurrent Extractors
cdm.large
8 vCPUs, 16 GB
16
cdm.xlarge
16 vCPUs, 32 GB
32
cdm.4xlarge
64 vCPUs, 128 GB
128
Figure 1 Setting Maximum Concurrent Extractors for a CDM cluster
- Configure the number of concurrent extractors based on the following rules:
- When data is to be migrated to files, CDM does not support multiple concurrent tasks. In this case, set a single process to extract data.
- If each row of the table contains less than or equal to 1 MB data, data can be extracted concurrently. If each row contains more than 1 MB data, it is recommended that data be extracted in a single thread.
- Set Concurrent Extractors for a job based on Maximum Concurrent Extractors for the cluster. It is recommended that Concurrent Extractors is less than Maximum Concurrent Extractors.
- If the destination is DLI, you are advised to set the number of concurrent extractors to 1. Otherwise, data may fail to be written.
Figure 2 Setting Concurrent Extractors for a job
DataArts Migration FAQs
- 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?
- 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?
- 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?
- How Do I Configure the Connection If Only Some Nodes in the 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 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 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 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 a CDM Connector Reports the Error "Configuration Item [linkConfig.iamAuth] Does Not Exist"?
- What Should I Do If Error Message "Configuration Item [linkConfig.createBackendLinks] Does Not Exist" Is Displayed During Data Link Creation or Error Message "Configuration Item [throttlingConfig.concurrentSubJobs] Does Not Exist" Is Displayed During Job Creation?
- 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?
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