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Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: chenxiaoxiong <chenxiaoxiong@huawei.com> Co-committed-by: chenxiaoxiong <chenxiaoxiong@huawei.com>
8.9 KiB
8.9 KiB
What Is the Number of Concurrent Jobs for Different CDM Cluster Versions?
CDM migrates data through data migration jobs. It works in the following way:
- When data migration jobs are submitted, CDM splits each job into multiple tasks based on the Concurrent Extractors parameter in the job configuration.
- 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
- 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.
Parent topic: DataArts Migration (CDM Jobs)


